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CO NBS TECHNICAL NOTE 885

U.S. DEPARTMENT OF COMMERCE/ National Bureau of Standards

jaflnMiiME

Nicaraguan Building Regulatory System
NATIONAL BUREAU OF STANDARDS

The National Bureau of Standards 1 was established by an act of Congress March 3, 1901. The Bureau's overall goal is to strengthen and advance the Nation's science and technology

and facilitate their effective application for public benefit. To this end, the Bureau conducts

research and provides: (1) a basis for the Nation's physical measurement system, (2) scientific and technological services for industry and government, (3) a technical basis for equity in trade, and (4) technical services to promote public safety. The Bureau consists of the Institute for Basic Standards, the Institute for Materials Research, the Institute for Applied Technology,

the Institute for Computer Sciences and Technology, and the Office for Information Programs.

THE INSTITUTE FOR BASIC STANDARDS provides the central basis within the United

States of a complete and consistent system of physical measurement; coordinates that system

with measurement systems of other nations; and furnishes essential services leading to accurate and uniform physical measurements throughout the Nation's scientific community, industry, and commerce. The Institute consists of a Center for Radiation Research, an Office of Measurement Services and the following divisions: Applied Mathematics — Electricity — Mechanics — Heat — Optical Physics — Nuclear

Sciences 2 — Applied Radiation 2 — Quantum Electronics 3 — Electromagnetics 3 — Time

and Frequency 3 — Laboratory Astrophysics 3 — Cryogenics 3. THE INSTITUTE FOR MATERIALS RESEARCH conducts materials research leading to improved methods of measurement, standards, and data on the properties of well-characterized

materials needed by industry, commerce, educational institutions, and Government; provides

advisory and research services to other Government agencies; and develops, produces, and

distributes standard reference materials. The Institute consists of the Office of Standard Reference Materials and the following divisions: Analytical Chemistry — Polymers — Metallurgy — Inorganic Materials — Reactor

Radiation — Physical Chemistry.

THE INSTITUTE FOR APPLIED TECHNOLOGY provides technical services to promote

the use of available technology and to facilitate technological innovation in industry and Government; cooperates with public and private organizations leading to the development of

technological standards (including mandatory safety standards), codes and methods of test; and provides technical advice and services to Government agencies upon request. The Institute consists of a Center for Building Technology and the following divisions and offices: Engineering and Product Standards — Weights and Measures — Invention and Innovation — Product Evaluation Technology — Electronic Technology — Technical Analysis — Measurement Engineering — Structures, Materials, and Life Safety 4 — Building

Environment * — Technical Evaluation and Application * — Fire Technology.

THE INSTITUTE FOR COMPUTER SCIENCES AND TECHNOLOGY conducts research and provides technical services designed to aid Government agencies in improving cost effec- tiveness in the conduct of their programs through the selection, acquisition, and effective

utilization of automatic data processing equipment; and serves as the principal focus within

the executive branch for the development of Federal standards for automatic data processing

equipment, techniques, and computer languages. The Institute consists of the following

divisions: Computer Services — Systems and Software — Computer Systems Engineering — Information Technology.

THE OFFICE FOR INFORMATION PROGRAMS promotes optimum dissemination and

accessibility of scientific information generated within NBS and other agencies of the Federal Government; promotes the development of the National Standard Reference Data System and

a system of information analysis centers dealing with the broader aspects of the National Measurement System; provides appropriate services to ensure that the NBS staff has optimum

accessibility to the scientific information of the world. The Office consists of the following

organizational units: Office of Standard Reference Data — Office of Information Activities — Office of Technical

Publications — Library — Office of International Relations.

1 Headquarters and Laboratories at Gaithersburg, Maryland, unless otherwise noted; mailing address Washington, D.C. 20234.

3 Part of the Center for Radiation Research.

3 Located at Boulder, Colorado 80302.

* Part of the Center for Building Technology.
WATIONAL llllfilSAU OP STAN55ABBQ

JtmaAKY

NOV a 6 1975

A Technical Review of the Nicaraguan Building

Regulatory System

Richard N. Wright g

f

Institute for Applied Technology

Center for Building Technology

National Bureau of Standards

Washington, D.C. 20234

and

Ing. Atilano Lamana

Instituto De Investigaciones y Ensayes De Materiales

Universidad De Chile

Plaza Ercilla 893 Casilla

1420 Santiago, Chile

Sponsored by

The Organization of American States The United States Agency for International Development

U.S. Department of State

and The National Bureau of Standards

v

'*«, o. **/

U.S. DEPARTMENT OF COMMERCE, Rogers C.B. Morton, Secretary

James A. Baker, III, Under Secretary

Dr. Betsy Ancker-Johnson, Assistant Secretary for Science and Technology

NATIONAL BUREAU OF STANDARDS. Ernest Ambler, Acting Director

Issued October 1975
Library of Congress Catalog Card Number: 75-600078

National Bureau of Standards Technical Note 885

Nat. Bur. Stand. (U.S.), Tech. Note 885, 85 pages (Oct. 1975) CODEN: NBTNAE

U.S. GOVERNMENT PRINTING OFFICE

WASHINGTON: 1975

For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402

Price $1.45 Stock Number 003-003-01476-1
Contents

1. Introduction 1

2. Lessons from the 1972 Managua Earthquake 2

3. Building Regulatory System 2

4. Nicaraguan Building Code 5

4.1 Emergency Code 5 4.2 Cart ilia de Construed' on 5 4.3 Draft Code 6 4.4 General Recommendations 6

5. Review of Designs 7

6. Inspection of Construction '. . . . 8

7. Organization of the National Laboratory and Standards

Activities 9

7.1 Relation Between a National Laboratory and Standards

Activities .9

7.2 Functions of the Nicaraguan Building Institute . . . .10

7.3 Relations with the National University 11

7.4 Relations with Private Laboratories 12

8. Organization and Objectives of the Laboratory 12

9. Educational Programs 15

10. Summary 16

11. References 18

APPENDIX A Itinerary and Contacts in Field Investigations . . .19

APPENDIX B Building Regulation for Earthquake Resistant

Construction 24

APPENDIX C Housing Performance in the 1972 Managua Earthquake 42

1 1

1

A TECHNICAL REVIEW OF THE NICARAGUAN BUILDING REGULATORY SYSTEM

Richard N. Wright

and

Atilano Lamana

The losses in the December 23, 1972, Managua Earthquake provided dramatic

evidence of the need for effective implementation of good building standards. Repetitions of these tragic losses elsewhere in Nicaragua and in a reconstructed Managua are certain unless a good building code is developed

and adopted, its use and design by architects and engineers enforced by

careful review of designs, and the implementation of these designs by the

builders assured by inspection of construction and testing of building

materials. A summary and critical review of U.S. building regulatory

practices for areas with severe natural hazards is presented in Appendix B for guidance in building regulatory system planning and development. A survey of housing performance in Managua is presented in Appendix C to

illustrate that earthquake resistant construction is feasible and economical for Nicaragua and other nations with comparable resources.

Keywords: Architecture; building; building codes; building design; disaster

mitigation; earthquakes; engineering; environmental hazards;

housing; inspection and testing; safety.

1. Introduction

This study of the Nicaraguan Building Regulatory System was sponsored by the

Organization of American States (OAS) and the United States Agency for International Development (AID). Major programs of reconstruction were made

necessary by the December 23, 1972 Managua earthquake. An effective building regulatory system is needed to assure the public health, safety, and

welfare in the reconstructed city, and to achieve these objectives economically.

Ing. Atilano Lamana, who led the study team and represented OAS, has investigated the effects on buildings of many Chilean earthquakes, participated in

the development of Chilean building standards, and heads the Chilean national

laboratory for building technology. Dr. Richard N. Wright, who represented

AID, was leader of the first U.S. building investigation team to reach

Managua following the earthquake and is active in the ongoing U.S. program to

revise seismic design standards.

The writers comprised a joint OAS/AID team which worked in Managua from July

9-21 and July 30-August 8, 1973, and in Mexico and Guatemala from July 23-30,

1973. The team consulted with Nicaraguan government officials, the professional and construction communities in Nicaragua and standards authorities

1
in Mexico, Guatemala, and the United States. An itinerary of these activities

appears in Appendix A. The recommendations and conclusions presented herein,

are based on these consultations, direct observations, and the references

cited from other investigations.

Many persons have assisted the writers in the collection and evaluation of

the information presented here. They thank each of the persons noted in

Appendix A for their help in the work.

2. Lessons from the 1972 Managua Earthquake

Most damages in the 1972 Managua e cies in building practices, defici

before in previous earthquakes, wh

appropriate seismic provisions in

of the earlier disastrous earthqua

ing code with seismic design re qui

it enforced only zoning regulation

regulatory system capable of effec

visions.

arthquake appeared to result from deficienencies which have been exhibited many times

ich would be avoided by implementation of

design and construction. However, in spite

ke of 1931, Managua did not employ a buildrements appropriate to its earthquake risk;

s. Furthermore, it did not have a building

tive implementation of building code proThe amon cent

i n t quak

than

the

with

none

er b dama

pri a nons

the

of t

meas

g th er o he e

e mo fiv

eart

the

of

ui Id

ges

te d true

ENAL

his

ured

e hi

f th

arth

tion

e st

hqua

sta

thes

ings

can esig

tura

UF a type

ace ghes

e ci

quak

s of

ori e ke r ted

e bu wer

be m nan

1 sy

dmi n of

el er

t re

ty.

e pr sue

s , w esi s obje

i 1 d i e se uch

d ch

stem

i str

dama

a t i o n corde

Howe

ove t

h i nt ere g tant

c t i v e ngs c vere ; reduc

oi ce

s , f u a t i o n ge co

of

d , a ver , hat

ensi ener

prac

s of

olla

how

ed f of s rni s bu i ntro

0.39g

nd ac the

it is

ty.

ally

t i c e s the

psed

.

ever

,

or 1 i truct

h i n g s

1 di ng

1 .

1/ [1]

eel er succe

f eas

The m

d e s i g of t provi

Pro

it i ttle

ural

, and are

of the Managua earthquake, ranks

ations probably were greater in the

ssful performance of many buildings

ible and economical to resist earthodern buildings of Managua, taller

ned and constructed in accord with

he western United States. In accord

sions [2], in this severe earthquake

perty damages in a number of the ta 11-

s widely recognized [3] that property

or no additional investment by approtype. The \/ery limited damages to

equipment in the Banco de America and

examples from the Managua earthquake

This section presents an overview of the building regulatory system and the

interrelationships between its elements to provide a framework for discussions of these elements in Nicaragua. A more detailed view of the organization and administration of building regulatory systems is given in

Appendi x B

.

The objectives of a building regulatory system usually include the protection

of the safety, health, and property of the citizens of the political unit

to which the building regulatory system pertains. Each person involved in

the building process: owner, planner, designer, manufacturer, builder, and

occupant has his responsibility and role. The purpose of the building

1/

lumbers in brackets refer to entries in the list of references.

2
regulatory system is to assure clear definition of each role and to make

appropriate checks to assure that each person with a role is capable of

meeting his responsibilities and carries them out faithfully.

Nicaragua has very limited experience with a building regulatory system;

most of this experience has been gained since the 1972 earthquake. Prior

to the earthquake, building regulations dealt only with land use and zoning.

There was no building code covering the practices of design and construction

or the quality of materials to be employed in construction. On January 24,

1973, Nicaragua decreed an emergency code [4]. This code is restricted in

coverage to the earthquake resistant design of building structures and

applies only in the city of Managua. It speaks to design, construction,

and control of the quality of building material. It calls for review of

plans and inspection of construction to assure implementation of the code

provisions .

In June 1973, the Oficina Nacional de Urban ismo published a Cartilla de

Construccion. This is a detailed guide to the construction of houses of one story which are constructed under the supervision of a builder without

participation of professional designers. The Cartilla covers the preparation of materials and the details of their employment in the most common

types of buildings.

The building code was drafted rapidly to meet emergency needs; the Oficina

Tecnica de Construccion Sismica Nacional was created within the Oficina

Nacional de Urbanismo of the Ministerio de Obras Publicas to: review

plans, designs, and calculations; review existing structures damaged in the

earthquake; inspect and control materials used in construction; supervise

construction and insure that structures are constructed in accordance with

plans; and conduct a number of longer range activities concerned with

development of improved building codes and practices. It is to be expected

that problems would be encountered with the emergency code and in its rapid

impl ementation . Prompt and effective resolution of these problems is important to avoid a crisis in the building regulatory system which could either slow the recon- struction of Managua and the further development of Nicaragua as a whole,

or else cause an end to efforts to effectively regulate the building process. The latter would mean that Managua and other areas of Nicaragua

could expect to endure disasters comparable to the 1972 earthquake again

and again in the future.

The r code

docum

and o

d e f i n c r i b e beam,

such

tant

ing p men , ards .

ef er and

ent

ccup

i t i o des

mat

as t ref e roce

etc

.

ence

the

requ

ants

ns o ign

eri a he p renc

ss

.

, in

docu

stand

i r i n g

. Th

f the

proce

Is su roced

e doc

Thes

thei

ments

ards

spec

e sta

qual

dures

ch as ure f ument

e may

r i nt

of th

to whi

i f i c a ndards

i t i e s such

the d or mea

s are

i n c 1 u erpret

e build

ch i t r cts on are te

cal 1 ed

as thos

e f i n i t i suri ng

the ai d de hand

a t i o n a

Building codes and the associated standards are not constant either in

space or in time. In space, they must be adapted to conditions of practice

in individual areas, to the objectives individual governments set for their

buildings' performance, to the nature of the materials available for buildings, and to the skills available in the design and construction professions

and crafts. In time, they change as new knowledge allows improvements in

practices, codes and standards, as the requirements of the public change, or

as the competences of the designers and builders develop. Thus, the develop-
merit and maintenance of building codes and standards is a major activity

within the building regulatory system. In Nicaragua which has a newly created and provisional building regulatory system, this is a particularly un- developed area of the system. There are few people in Nicaragua experienced

in development or maintenance of building codes. An institute for building

standards is needed for the development and maintenance of standards and for

technical support for the process of the development and implementation of

the legal building code.

Laboratories are essential to evaluate and control the quality of building

materials. Many laboratories are involved; industrial laboratories for

quality control by the manufacturer, private laboratories to provide testing services for professional architects and engineers, and contract ser- vices to governmental agencies, and the national laboratory responsible for

direct quality control in selected areas, and for accreditation of the

industrial and private laboratories.

A broad range of education programs are essential for support of an effective building regulatory system. Continuing professional education is

needed for the architects and engineers in Nicaragua; immediately to bring

them abreast of the latest and best practices for earthquake resistant

design so important for the reconstruction of Managua; in the long range to

keep them up-to-date in building technology which is a broad applied field

changing with and benefiting from advances in most disciplines of science

and technology. However, the most critical need for education in Nicaragua

appears to lie in the subprofessional areas for craftsmen such as welders,

masons, and plumbers, foremen and supervisors, draftsmen, inspectors, and

laboratory technicians. The high productivity needed in the construction

industry of Managua for the rebuilding effort will be possible only if

these subprofessi onal s can carry out effectively their roles in the building process.

Nicaragua now has an embryonic building regulatory system established in

response to the emergency created by the December 23, 1972 earthquake. One

major problem with this system is its scope. It pertains only to Managua

and covers only the design of the structural system for earthquake loading.

It is important for the safety and economic well being of the citizens of

Nicaragua that the activities of this system be expanded to cover all building construction in Nicaragua and all significant aspects of the performance

of buildings.

The growth of this system must be well planned to avoid assumption of

responsibilities which cannot be carried out. This would result in a loss

of construction productivity, an increase in cost, and the loss of confidence of the citizens of Nicaragua in the ability of their government to

regulate construction of buildings. Experience [5] indicates that the ideal

organization of the building regulatory system provides:

o focus of all code enforcement activities in one agency

o that the chief of this agency have direct responsibility to the

chief executive of the level of government responsible for building regulations

o that code enforcement be the sole function of this agency

The organization of the Nicaraguan building regulatory system within the

Oficina Nacional de Urbanismo is in accord with the first and third of

these points. Its location within the Ministerio de Obras Publicas gives

that Minister both building program responsibilities, such as the construction of highways and public buildings, and the regulatory responsibility.

The building regulatory system would have fewer potential conflicts of

interest if it were made a separate agency within the executive branch of

the Nicaraguan government.
4. Nicaraguan Building Code

The building code is a legal document requiring that design and construction be in accord with the specifically stated provisions or explicitly

cited standards. The status of and the needs for the building code and its

associated standards in Nicaragua were discussed with officials of the

Ministry of Public Works, members of the design professions and the builders. Discussions dealt with the texts of the January 1973 emergency code

and the draft of the proposed building code.

4. 1 Emergency Code

The erne

e n g i n e e tural d of elem

the des

bui 1 di n

u n s e r v i structu

Review

resi sta

and mem

the s e i ci es :

rgenc

rs wo

e s i g n ents

ign o

g in

ceabl

ral c Commi

nt de

bers

smi c

y cod

r k i n g for

of th

f the

confo

e , un

a p a c i ttee

sign,

of th

p r o v i

e , wh

wi th

sei sm

e bui

stru rmanc

safe

ty fo

feel s Aft

e Ni c

s i o n s

ich wa forei

i c 1 oa

1 d i n g ctural

e with

from h r the

the c

e r di s aragua

of th

s dev

gn ex

ds.

other

syst

the

azard

i n t e n ode i c u s s i n des

e erne

el op

pert

That

tha em o emer

s su ded

s se ons

i gn

rgen

ed in

s, ap

is,

n the

nly f gency

ch as purpo

r v i n g with

profe

cy co

Janu

plies

i t do

stru

or ea code

f i re

se

.

reas

the S

s s i o n de ha

ary 197

e x p 1 i c es not

ctural

rthquak

coul d

, and 1 The N i c onably

e i s m i c

s , the

ve the

3 by

itly

regu

syst

e 1 o be f acki

arag

wel 1 Code

writ

foil

Ni car only

late t em and

adi ngs

u n c t i o ng in uan Se

for e Revie

ers be

owing

aguan

to struch e design

regul ates

Thus , a nal ly quite

adequate

i s m i c Code

arthquake

w Committee

1 i eve that

def i ci eno eol o icar

ei sm ency

his

rtic

trie

true

ati c sed

rds

ual i tsel

rol

he s ppea

his

f sa

he s auge

n ex vail

idel

t re tand

een

gical

aguan

i c ha

code

area . le 33

t con

t i o n . test

in re must

ty of

f mus proce

treng

rs to amoun

fety.

tanda

stee

pi ana able

y rec fers

ards

diffi

evidence suggests that all of Pacific Nicaragua (the

graben and coastal range) is exposed to a degree of

zard comparable to that of Managua. Therefore, emer- provisions should be applied to buildings throughout

refers only generally to the requirement of exercising

trol on the quality of materials and procedures of con- Because of the vagueness of this statement, no systei ng is conducted to control the quality of materials

pairs or new construction. Throughout the code, standbe referred to which call for explicit control of the

materials and procedures of construction, and the code

t call explicitly for enforcement of these quality con- dures . th required for masonry units and mortar in Article 26

low while the allowable unit stresses appear too high;

ts to a compounded infringment upon the normal factor

rds referred to in the emergency code do not cover light

1 and timber construction which are prevalent in Managua

tory commentary, design manuals and design examples are only for the provisions of the emergency code which use ognized U.S. standards.

to design standards of United States; use of these

written in English with the U.S. system of units, has

cult for some Nicaraguan designers.

4.2 Cart ilia de Construccion

The Cartilla de Construccion is a handbook of construction for nonprofessionals such as foremen and small contractors. These persons, working

without professional design assistance, are responsible for approximately

80 percent of the housing units in Managua. The Cartilla which was issued

in June 1973, has been very helpful to the intended users and to subprofessional building inspectors.
4.3 Draft Code

The draft proposed code was submitted for review of the Nicaraguan Seismic

Code Review Committee in May 1973 by the Secretary of Public Works of

Mexico. The draft was prepared by a group in the National University of

Mexico working under subcontract with the Mexican consulting firm DEPLAN

which is the contractor for this work to the Mexican Secretary of Public

Works. Discussions with the Mexican group which drafted the code, indicate

that it is yery closely based on a new code for the Federal District of

Mexico which this group is also preparing.

The scope of the proposed code is limited to design of the structure; it

does account systematically for all types of loading on the structure. It

is indicated that the strategy for this code could be applied to all aspects

of buildings and the structural loading provisions generalized so as to

allow the code to be applied throughout Nicaragua.

Based on discussions with the Nicaraguan Seismic Code Review Committee and

the Mexican group which drafted the code, the writers believe:

The

saf

tio

not

nei

gua

and

The

to

Ear

dif

und

und

rep

The

ste

mat

propo

ety an

n of t conta

ther a

n e n g i stand

new c assure

ly imp

f i cul t erstan

er ext

1 aceme

propo

el and

eri al

s

sed

d pr

hi s

i n a re d neer

ards

ode

tha

1 erne si n d an reme

nt o sed

tim

i n

code emp

esents r phi 1 osop

comment

e s i g n a i s in und

loys an advanced philosophy of structural

elatively novel standards for implementahy. At present, the proposed code does

ary explaining its provisions in detail;

ds or examples available to assist Nicaraerstanding and implementing the philosophy

prov

t th

ntat

ce N dap

tim

f ea code

ber

Mana

1 si o ey a ion

icar

ply

e pr

rthq

doe cons

gua.

ns have not been used enough in practice

re complete, correct, and unambiguous,

of the proposed code in Nicaragua would

aguan designers would have to learn to new techniques at a time when they are essures to meet needs for repairs and

uake damaged buildings,

s not provide standards for light guage

truction; these are extensively used

be

The draft code is a promising forward step in structural design standards.

Mexican experience with its use will correct problems that may exist in the

draft and lead to the development of the necessary design aids. It promises to provide a major resource for the development of a Nicaraguan building code

.

4.4 General Recommendations

The process of development of a new Nicaraguan building code cannot be seen

as an emergency activity. Code development is a process which requires

substantial inputs from all segments of the building community (designers,

building regulatory agencies, manufacturers, and builders) and thorough

study to assure that an appropriate balance is achieved between risks to

public health, safety, and property and the investments required to reduce

these risks. This suggests that several years should be allowed for develop'

ment of a new Nicaraguan building code, and that the process of development

should take full advantage of parallel activities in Mexico, the United

States, and other countries of the world.

Nicaraguan building codes and standards must have substantial inputs from

the Nicaraguan building community to assure their effective applicability

in Nicaragua. As discussed in more detail elsewhere in this report, it is

recommended that the code and standard development activities become a responsibility of a Nicaraguan institution concerned with building standards. An immediate activity of this institution of building standards
should be the amendment of the emergency code to remedy already identified

defects .

The process of development of a new Nicaraguan building code may be inappropriate for Nicaragua to undertake alone. It is a major technical effort.

Since conditions of service, natural hazards and practices of the building

community are closely related throughout Central America, it appears appropriate to explore an appropriate international organization for a code

development process applicable throughout Central America. This also is

recommended by the second Central American Congress on Earthquake Engineering held in San Jose, Costa Rica, August 2-4, 1973.

5. Review of Designs

Review of designs is a major element in the building regulatory system. It includes review of design calculations, plans for the building, and the

specifications governing the materials and fabrication to assure that the

projected building is designed in accord with the building regulations.

Review of projects costing more than Cordobas 20,000 ($2,900) is conducted

in the National Technical Office of Seismic Construction. The status of

this office's review of designs on July 19, 1973 amounted to 50 projects

awaiting review, many for the second time, with reviews completed at a rate

of approximately 15 per week. This indicates an average waiting period of

three weeks; some members of the Nicaraguan professional community said that

their projects have taken two-three months for completion of reviews.

At the time of the investigation, review of designs had been conducted in

Nicaragua for only six months. This was a time of emergency in the preparation of building designs; it was certain there would be problems with the

process. The reviewers stated that many plans and calculations were incomplete, the work was not organized systematically, it is difficult to determine what assumptions were made, where numbers were taken from, and where

they were to be used. Some professional practitioners said that the review

was overdetai 1 ed , most calculations were recomputed, elements were redesigned

in the review, and, therefore, the reviewers may appear co-responsible for

the design. These problems occurred with a work load which was mostly re- pairs and designs for buildings of one and two stories. They were expected

to become worse when the redevelopment plans were defined and more substantial projects were designed.

The office had problems with the turnover of professional staff who find more attractive employment in design practice after learning to review

efficiently. It was also noted that for some buildings, work started before

obtaining a permit, occupancy was attempted without a permit, and attempts

were made to use influence to obtain waivers of the normal procedures of

review and inspection.

The wri

the des

work he

the pi a builder

consi de

which m tance t job cov

of mate

spot ch

rectly . dupl i ca revi ew

i s poss

ters

igns

has

ns d can

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ay i o wi er t rial

ecki

It ting

proc

ible

cons i have

under

e s c r i b under

1 the

ncl ude

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he req

s. Th

ng of

is no

, i n i ess , w only

der the

the pro

taken . e the i stand t code re emerge

ding, e

u i r e d f

e compe

typi cal

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t s e n t i h i c h is

if the

obje

per s To a ntend

he in

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tence

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p r i a t rety ,

i n t submi

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the p

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the de

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e de

the

sign

the

es i g the

i ci e gner

rman ear

i cat

e qu

s as

t th

desi

sign

pub

i s

d e s i g ner i revi

nt de

, tha

ce of

thqua

ions

a 1 i ty

sured

ey ar

gn th er . lie a wel 1

n to as

s compe

ewer mu

tai 1 , t t the c the bu

ke load

devel op

and fa

by sys

e carri

e struc

An effi

nd the

o r g a n i z

sure that

tent for the

st see that

hat the

alculations

ilding

i ng , res i s- ed for the

b r i c a t i o n temat i c ed out corture by

c i e n t designer,

ed so that
the reviewer can clearly trace the concepts of the designer through the

plans, calculations and specifications.

Educat

United

in Urb

Such a cess . guides

di rect

their

haps o Ni cara

from o the I n f i rms , vices

i on of

Nation

am* smo progra

An imp

for su

1 y with

work fo

f less

guan bu

ther so

t e r n a t i which

to buil

desi g

s was

g i v i n m wou ortan

bmi tt

the

r rev than

i 1 d i n urces

onal

regul

ding

ners

cons

g on1 d pr

t par

al of

Ni car

iew. one y

g reg

; in

Confe

arly

regul

and re

i d e r i n t h e - j o

o v i d e

t of s proje

aguan

A rel ear in

ul ator

the Un rence

provi d atory

viewers can

g a mission

b- trai ni ng

additional

uch assi sta

cts for rev professiona

a t i v e 1 y , s h duration,

y system,

ited States

of Building

e both desi

agenci es , a

resolve these diff

of foreign experts

to their Nicaraguan

help to accelerate

nee should be the p iew. The experts s

1 firms to train th

ort-range program o should prevent a cr Comparable expertis

alone model code a Officials or q u a 1

i

gn services and con

1 so are capable of

i cul ti es . The

to work directly

col 1 eagues . the review proreparation of

hould interact

em in presenting

f this type, peris i s in the

e is available

gencies such as

f i ed consul ti ng

tract review serthis assistance.

For the longer range, the Nicaraguan building regulatory system needs a professional development program to assure growth in the competence of its

reviewers of design. Attractive salaries also are required so that highlyqualified personnel are not lured away to private practice.

There

condu

build

d e s i g

a c t i v commu

be on much

erly

appro

caree

al s w membe

whose

of hi

when

1 s ct o

i ng

n, i

i ti e ni ty

ly a of i cond

ach . r of

1th

r of wor

s pr

a de

an a f al

code

t wi

s to

. Th

cad

ts t ucte

Re

not

the

the

k he

of es sign

1 terna

I revi

is au

II be

prope

en the

re, hi

ime to

d. Th

view o hi ng b necess

revi e must

,

s i o n a 1 er in

ti ve ews gmen

poss

rly

rev ghly

ass ere

f Pi

ut r ary

w st

fro

act

a pr

whi

with

ted

ible

qua!

i ew

cap

uri n may

ans evie

capa

aff

m ti

i v i t of es

ch may

i n the

by sta

to co

i f i e d staff

able i g that

be pro

i s a v w of p b i 1 i t i of Urb

me to

i es . s i o n a 1

red

Of i ndar

ntra

f i rm of t

n re the

f ess ery

1 ans

es . ani s time

Howe

f i r

uce t ci na

ds fo

eta

s i n he Of

vi ew cont

ional

impor

i s n A co mo wo revi ver , m wor

he prob

N a c i o n a

r the s substan

the N i c

i c i n a N a c t i v i t ract re advant

tant pr

ot attr

n f 1 i c t rks par

e w , in

there i ks some

1 ems a

1 de U ubmi tt

t i a 1 p aragua

a c i o n a

i e s it

view a ages t ofessi

acti ve of i nt

t - 1 i m e order

s no c times

n si n rbani

al an art o

n pro

1 de

self,

c t i v i o the

onal

to m erest

for

to ac

o n f 1 i on re

g f r smo

.

d re

f th

fess

Urba

but

ties

con acti

ost

may

a de

hi ev ct o vi ew

om t Wh

view

e re iona

ni sm dev

are trac

vity

prof

exi

sign

e a f in

heen the

of

view

1o need

o t i n g propting

, but a e s s i o n

- st if a er

,

bal ance terest

Another problem in the review of designs was noted. Some Nicaraguan governmental agencies with construction responsibilities may be proceeding

with design and construction practices which are not in accord with the

building code. The Government of Nicaragua should have a policy on the

codes and specifications to which governmental buildings will conform; the

policy should make the Oficina Nacional de Urbanismo responsible for assuring

compliance with the regulations.

6. Inspection of Construction

A system for inspection of construction by the building regulatory authorities has existed in Managua only since the establishment of the Oficina

Tecnica de Construccion Seismica Nacional following establishment of the

emergency building code in January 1973. The inspection force in this

office is headed by a professional engineer and employs nine, fifth-year

engineering students as inspectors. Their work load in mid-July amounted

to approximately 15 schools and 120 private buildings under construction.

The Seccion de Permissos of the Oficina Nacional de Urbanismo also employs

field inspectors to assure that construction and occupancy do not occur without permits.
Discussions and field visits with the inspectors indicated that these students

responded responsibly to the opportunity to participate directly in the emergency. They carried out their duties thoughtfully and in general, effectively. A manual and a check list for inspectors were needed to assure more systematic and uniform inspections. Apparently because of the vagueness of

the emergency code, inspection did not include any quality control of materials or taking and testing of samples. Inspection activities were reported

to be hampered by a shortage of vehicles, only three available to the group.

The activity of inspection is an essential part of the building regulatory

system for all Nicaragua; it should be institutionalized by the development

of a permanent body of inspectors. These should be skilled subprof ess i ona 1

s

under the direction of a professional engineer. The inspectors should receive

salaries adequate to allow them to concentrate on their responsibilities for

the life safety and property of Nicaraguan citizens. The skills and salaries

should be comparable to those for good construction foremen or laboratory

technicians. Formal training programs are essential for qualification as a building inspector since the breadth of responsibility exceeds the knowledge

of any construction craft or subprof essi onal skill in the background of a potential inspector. Furthermore, formal classes and examinations provide a useful third-party evaluation of his character and intelligence. The inspector must have legal authority to stop unacceptable work and must inspect for

conformance with specifications for materials as well as the geometrical

requirements of the plans.

A manual of practice and appropriate report forms must be prepared for

inspectors. These are essential for guidance and consistency on the job

and will be equally useful resources for the formal training program.

Experience [3] elsewhere indicates inspection by the building regulatory

authority alone is not enough to assure proper quality of construction.

The owner should be required to engage professional services for surveillance of construction as part of the professional services required for

design. The designer is exceptionally well-qualified to recognize occurrence of conditions which were not anticipated in design and to assess the

builder's implementation of plans and specifications. This surveillance

should in no way reduce the builder's responsibility for compliance with

the plans and specifications. Responsibility of both the designer and the

building authority for inspection of construction provides additional assurance of compliance which has been shown effective by the good earthquake performance of California schools constructed under provisions of

that state ' s Field Act.

There are also examples of poor performance of buildings for which the owner and builder was essentially one entity. For these situations, an especially stringent review of design and inspection of construction should

be provided by the building regulatory authority at the expense of the

owner-bu i 1 der

.

7. Organization of the National Laboratory

and Standards Activities

7.1 Relation Between a National Laboratory

and Standards Activities

Nicaragua's present problems in developing a building code are not of

transient nature. A building code must be continually under revision;

furthermore, it must be complemented by many standards. Therefore, a permanent office of standards is needed for this work. This organization

would not develop a totally original building code and standards. Rather,

it would coordinate the work for national adaptation of international

standards and represent national interests in international standards

activities.
There are many advantages in adopting international standards. They include

economy of effort in development of standards for national application, benefits from advances in international technology, and qualification of the

national products for foreign trade. Therefore, it is recommended that this

office of standards be closely related with ICAITI (Instituto Centro Americano de Investi gaci on y Tecnologia Industrial) and support it in the discussion and promotion of a building code and building standards for Central

Ameri ca

.

A building code must account for local conditions of practice, as well as requiring technically sound uses of fundamental principles and methods of

design. The properties of local building materials are of principal significance; the experimental information required to define these can be

developed by a national laboratory for testing of materials. The work of

this laboratory may be coordinated with foreign laboratories, especially

those of Central America in connection with ICAITI, to plan joint investigations on problems of regional nature relevant to the development of a Central American building code.

However, it is not enough to have a building code; it also is necessary to

provide for its enforcement. At present, enforcement lacks the support a national laboratory for testing of materials could provide in direct quality

assurance and through accreditation of private laboratories.

Because these close relationships between the office of standards and the

national laboratory are essential to their effectiveness, and to reduce

their operational costs, it is proposed that they be integrated into one Nicaraguan Building Institute.

7.2 Functions of the Nicaraguan Building Institute

The principal functions are:

nspec

ccred

t a n d i he qu

he I n ion o roced

ontro

ion m or th

ill t pon t f fac

ipes,

oul d

e sam ontro

uard

ny re

g e n c i he In evel o

c t i v e ill g ill o

u n c t i

I a s s i

I

I

owa

or sp

here

f the

ti on

i t a t i ng.

al i ty

s t i t u f the ures .

1 of

a t e r i e pro

ake p he so toryfloo

analy

pi ed

1 of

the r jecti

es wh

s t i t u pment

ly i n

i ve e btai n ons i fying

ble s e c i f i

i s ne

1 oca

of t on o The

of

te r pri

qual

als

tect

1 ace urce made

r ti ze t at t qual

egul

on o

i c-h te.

of

the

xper

sta

n co mat

tres

est

ed f

1 ma

he private laboratories. The Institute shall provide

f the private laboratories to give their tests legal

Institute will exercise periodic inspection to assure equipment and testing procedures. For this function

equires instruments and expert personnel for calibravate laboratories' equipment and evaluation of their

ity.

at t ion

i n of

pro

les,

he s he c ity

atio

f pr

woul

Th

heir

of c the

the

duct

asb ourc

usto

may

n of

oduc

d ac

e Ins

ori g onsum

facto

mater

s sue estos

es of

ms ho

be ex the

ts wo

t on

t i t u t e in, be

e r s in

ry, qu

i a 1 s . h as c cemen

sand

use an tended

nation

ul d be

the ba

will

fore

c 1 u d i arry,

This

ement

t , an and g d tes

to m

1 s ex held

sis o

asse

they

ng th or c woul

, 1 im

d 1 urn ravel

ted i ateri

ports

by a f the

ss th are d

e sma ustom

d be

e, gy

ber .

. Im

n the

als f

. Th

pprop

test

e qua

i s t r i llest

s hou

the m psum,

The

porte

1 abo

or ex

e leg

r i a t e repo

lity

buted

. Th

se , d eans

bri c

I n s t i d mat

rator

port

al au gove

rts p

of c for

i s i epen

for

k, b tute

eri a y.

i n o thor

rnme

rovi

onstrucsale,

nspection

ding

control

1 ocks

,

al so

1 s woul

d

This

rder to

ity for

ntal

ded by

codes and standards. The Institute would participate

development of codes and standards; its laboratory

imental support for their preparation. The laboratory

tistics on the qualities of national materials from its

ntrol of quality. These are vital information for

eri als, determining their admissible applications and

ses. The laboratory also may conduct research programs

udies related to standards. For example, at present

or a study of the shear strength of masonry walls made

terials (blocks, bricks, cement, lime, sand).

10
Eval u new u prove

el erne

s t u d i peti t

D i s s e know!

o r i g i a cat

Testi

servi

f i c a t

i ng t The i with

Educa

equip

educa

usef u these

work

nati o Also,

will

its p

ati on a ses of

m e n t s i nts to es of c ions, e m i n a t i o edge, p nal or

al og of

ng. Th ces to

ions, s he serv

n s p e c t i the Ins

t i o n . ped 1 ab

ti on .

1 i n co

s. The

will en nal i n t the pa

help it

rof essi

nd d

1 oca

n th

veri onne

tc.

n of

repa

i n t the

e In the

tudi

ices

on s ti tu The

orat

The urse

pro cour

eres

rti c rec onal

evelopment. The

1 raw mater i a 1 s i e qual i ty of pres

fy their design a ctions, evaluate

Institute will carry out studies on

n construction, study possible iment materials, test prefabricated

nd fabrication, make experimental

the various proposals in design cornknow! ed

re recom

ran si ati

materi a

s t i t u t e , Mi ni s try

es of ma which a e r v i c e s te for t

u n i v e r s i ory to s f a c i 1 i t i s on mat

blems re age the

t and co

i p a t i o n ogni ze t staff.

ge.

mend

ons , Is f asof

teri

t pr

of b he t ties

tren

es o eri a cogn

stud

ntri

of t he m

The

ed pr

orga

or wh

the n Publ i al s , esent

u i 1 d i e s t i n shou

gthen

f the

Is an

i zed

ents

bute

he st

ost c

I n s t i a c t i c ni ze

i ch i a t i o n c Wor

and c are

ng re

g of

Id ha

thei

1 abo

d i n in da

to se

to th

udent

apabl

tute

es f tal k t ma

al 1 ks i ontr

cone

gula

samp

ve f

r pr

rato

the

ily

lect

ei r

s i n e wh

will

or co

s and

i n t a i abora

n the

ol of

erned

tory

les t ree a ogram

ry wi

prepa

conta

thes

prof e the

en th

d i s t r i b u nstructio

semi nars

ns standa

tory, wi

1

devel opm

qual i ty , only wit

agencies

aken on t ccess to

s of prof

11 be par

ration of

ct wi th t is topics

s s i o n a 1 d work of t ere is ne

te pe

n whe

, and

rds .

1 pro

ent o thus

h hi g may c he jo

this

ess i o

t i c u 1 prof

he la

of r

e vel o he In ed to

r t i n e n t ther

prepare

vide

f s p e c i - ampl i fyhways

.

ontract

bs.

wel 1 - nal

arly

e s s i o n a 1 boratory

eal

pment . s t i t u t e increase

For all these reasons, it appears necessary to locate the laboratory

close to the two universities of Managua.

o Arbitration. The Institute can serve as the supreme technical

authority in resolution of contractual problems.

o Training. The Institute can collaborate in the training of subprofessional technical personnel by making available its physical

facilities and recommended practices.

7.3 Relations with the National University

In some countries, the laboratories of the engineering school of the

national university function as the national laboratory. At first view,

this would be a possible solution for Nicaragua; it is examined by an analysis of its advantages and disadvantages.

There are various factors favoring the concept as follows:

The u of ju

A tes

v e r s i The a resou Contr

s tude

h o s p i an ex and t

i s t i c edge

Equi p The a bl ems

n a t i o

m versi

dgment

ting p r ty extr

v a i 1 a b i rces av

ol of q nts con

tal for

eel 1 ent

he qual

perspe

in t h e

i

ment in

c t i v i t i r e q u i r nal i n t

ty constitute

and a high 1 e ogram for con

a financial r

1 i ty of good

ai 1 abl e to th

uality of bui

tacts with pr

a medical sc means for st

i ty of its ma ctive of mate

r 1 ectures . the laborato

es in control

i ng research . erests and th

s an

vel o trol esour

1 abor

e stu

1 d i n g

a c t i c hool . udy o

t e r i a rials

a r b i t r a f knowl

of qual

ces whi

atory e dents . materi

e compa

Also,

f the n Is. Th

' perfo

tor with recognized independence

edge

.

ity of

ch can

qui pme

materials gives the unisupport research . nt improves the educational

a 1 s in

rabl e the p a t i o n

' ey can rmance

ri es also may be u of quality of mat

Research will be

e real technical q

the universities gives the

to those in a clinical

rofessors have available

s construction practices

give the students a realby incorporating this knowl

sed in university research,

erials will disclose probetter focused on the real

uestions if the investi gall
tors participate actively in problem identification, research planning

and planning for application of research results.

The disadvantages of placing the Nicaraguan Building Institute in the

National University are as follows:

o Th

re

laon

zeon

veAsor

wo

Th

ac

reec

Th

of

di

ge

Th

e um

petit

borat

the

ns . the

rs i ty

a co atory

rk an

e 1 ar

a d e m i

1 a t i v

o n o m i e , nat

acti

f f ere

rs of

e res

versi ty

ive work

o r i e s m u economi c The inte

preserva

cannot

nsequenc

must sa

d admi ni

ge volum

c staff,

e academ

c and ad

i o n a 1 la

v i t i e s c nt from

s tri kes

earch in

laboratories would have to carry out a large volume of

which is not directly in its interest. The national

st serve the interests of the state, which are focused

development of the country and the safety of its citirests of the university are different; focused primarily

tion, transmission, and growth of knowledge. The unicommit itself fully to goals different from its own.

e, the professors or researchers who work in the labor i f i c e a large part of their time in routine technical

stration which interfere with their academic careers,

e of routine work mentioned above requires a large nonThe laboratory attains a size much larger than its

ic importance in the university and can become a severe

mini strati ve burden.

boratory in its work of control of quality has a rhythm

orresponding to those of the building industry, which is

that of the university. There are also increased danor riots interfering with laboratory functions,

terests of the State and university may differ.

In the balance of advantages and disadvantages, it seems inconvenient to

make the university

great advantages in

national laboratory

versity should have

oratory .

responsible for the national laboratory. But there are collaboration. Therefore, if at all possible, the

should be located close to the university and the unia definite role in the activities of the national 1 a b

-

7.4 Relations with Private Laboratories

In addition to the laboratories of the National University of Nicaragua,

which presently provide quality control for building materials, there also

exists in Nicaragua, two private laboratories; LAMSA and NICASOLUM. These

laboratories work principally in soil mechanics, but also test building

materi al s

.

The creation of the Institute would not cause a reduction in the activities

of these laboratories. On the contrary, their volume of work should in- crease because of the work required in the reconstruction, and particularly

because of the greater requirements for control of quality of materials

which should be called for in the building code

A properly equipped laboratory of the Nicaraguan Building Institute is

essential to the building regulatory system. For development and revision

of building codes and standards, the laboratory must provide the necessary

12
experimental knowledge, including data obtained from quality control testing and from special experimental programs. The laboratory must participate

in the implementation of the building code, directly through control of

quality of materials and indirectly through inspection of private laboratories. The laboratory also must participate i n "educa ti on , in the vocational education of technicians and building tradesmen, in the curricula of

engineering students, in thesis research for professional degrees, and in

post-graduate research for professionals.

For the o fol 1 ows

specific

building

abbrevi at

t i o n . As

other thr

sary to c tory for

equi pment

rganization of the laboratory, these functions may be classified

tests for control of quality; special studies for evaluation of

designs, research, or development; teaching and demonstrations of

practices; and inspection of other laboratories. These may be

ed, respectively, as: control, research, teaching, and calibraide from the last function, which requires special methods, the

ee have many methods of testing in common. However, it is neces- onsider co-existence of these three functions in the same laborathe selection of the number and type of testing machines and

as

These

cementi ng

functions must be carried out for the

aterials, bricks and tiles, metals, wu convenience in use of equipment and test methods,

organized in the following sections:

various materials which

woods , and pi asti cs include:ds , and plastics. For

the laboratory may be

1

4.

5.

Bind

be d rel a will

aggr

sect

Cone

be i prob

they

Pref

pipe

with

betw

qua!

Meta

and

of t al so radi

Wood

grad

such

ers , edi c ted

hav

egat

ions

rete

n pe

1 ems

kno

abri

s, j con

een

ity

Is f cabl

he s wou

ogra

s .

i ng

as

which includes cements, limes and gypsums. This section will

ated to the control of quality and to problems of development

to these materials or procedures for their use. This section

e equipment for tests of mortars, of admixtures, and of alkalie reactions; it will provide appropriate services for other

s , agg rmanen which

w of t cates

oi sts , trol o them,

of pi a or con

es , st

peci me

Id be

p h i c c Charac

c 1 a s s i doors

rega

t CO

may

he e for

wal

f qu

Thi

s ti c trol

ruct

ns w resp

ontr

teri

f i ca and

tes a ntact

exi s xi ste

tests

1 pan

a 1 i ty

s sec mate

of q ural

ill b ons i b ol of

z a t i o ti ons

wal 1

nd mor

wi th

t , and nee of

of br

els, p of th

ti on , rials,

ual i ty

shapes

e samp

1 e for

wel di

n of t

, stud

panels

tars . the j they

spec

i cks , ol es , ese e or Wo

espe

of r

, 1 ig

led i nond

ng.

he na

i es o

Th

ob s mus

ial

bio

etc

1 erne ods , ci al

ei nf

htwe

n th

estr

e pe

i tes

t vi

prob

cks ,

. T nts

may

ly o orci

ight

e Cu

ucti

rsonnel o in order

si t those

1 ems . tiles, a his s e c t i and probl

include

f safety

ng bars , sections

stoms hou

ve testi n

tional woods, bas

f adhesi ves , and

f this section must

to identify the

job sites where

sbestos cement,

on will be concerned

ems of connections

the control of the

hel mets . pre ten si on i ng wires

, etc . A 1 arge part

se. This section

g of metals including

ic unit stresses,

studies of el ements

The mechanics of soils and bituminous materials are not included in the

first stage, because some capabilities exist in

and the Highways Laboratory. However, if it is

Highways Laboratory with the Institute, it will

improve the existing equipment.

the private laboratories

decided to integrate the

be necessary to review and

The work of controlling quality requires inspection in factories where

specimens will be taken with appropriate methods. It is recommended that

quality control not be limited to providing certification of specific

pieces or lots of production, but be extended to the statistical interpretation of test results to judge the quality of products with values of

averages, standard deviations, histograms and fractions defective. In this

way the laboratory serves in an advisory role to the manufacturer and the

13
builder, as well as in support of the building regulatory system.

It is beneficial to the building community and building users to publish

the useful information arising from these tests, with care to avoidance of

commercial conflicts. Examples of useful knowledge include the characteristics of the common aggregates, the current values obtained on the job

sites for the strengths of concretes and their dispersion, and the qualities of the foundation soils in different parts of the city. Similarly, it

would be desirable to make and publish special studies to characterize the

national timbers, to recommend typical proportions of concrete and mortar

mixes for small projects, to provide curves of correlation between strength

and rebound of the Schmidt hammer, etc.

The Institute's programs for special studies will be established to meet

the most important needs of the Nicaraguan building community. Strong

candidates for study include the improvement of pozzolans, use of lightweight aggregates, mix proportions for mortar for maximum bond to masonry

units, and studies of shear walls. The importance of courses for the

training of welders is emphasized; they would become more necessary in the

event of an increase in the volume of steel construction. Also, welders

must be periodically requalified, and it is necessary to impose radiographic control of welding in metal construction.

The requirements for laboratory equipment can be compiled from the ASTM

standards which define testing procedures and equipment for the various

building materials. Many equipment suppliers can recommend lists of

equipment as well as providing quotations of prices.

There are well-defined items of equipment for which it is only necessary to

select the maker, and sometimes to decide on the number of elements when

more than one is required. However, in other instances, and particularly

for multiple use equipment, there are more decisions to make. In this

latter class are testing machines, extensometers , measuring instruments and

recording apparatus. At least three testing machines are needed for tests

of specimens of various materials, each one with various scales and in

conjunction covering a range from zero to about 100 metric tons in tension

and to about 200 metric tons in compression. They must have load-deformation recorders and implements such as various grips, loading plates,

supports for flexure and bend tests, etc. A machine for testing pipes and

a small machine for tensile tests of mortar briquettes also should be

considered. A testing machine made up of two frames with hydraulic jacks

should be installed for tests of structural elements such as tests of walls

under horizontal forces.

The equipment required for measurement of deformations includes electrical

resistance strain gages for use in the laboratory and in the field with a bridge, connection box, and multiple channel recording apparatus. Mechanical

and optical extensometers of various types are required with calibration

equipment for all the deformation measuring instruments.

The loading ranges of proving rings for calibration of testing machines

must provide for the apparatus in the laboratory and in other laboratories

of the country.

Ultrasonic and portable x-ray equipment

testing of metals and welds.

is required for nondestructive

Equipment with a guarded hot plate, should be provided for measurement of

thermal insulation.

The following equipment is recommended for the concrete laboratory. There

should be two mixers of distinct capacities with vertical axes, a vibrating

table and immersion- type-vibrators, a core drilling apparatus, various

14
Schmidt hammers with a calibration anvil, a device for location of the

position of reinforcing bars within concrete elements, and a curing chamber

to be used for both cements and concretes.

list of equipment,

for the laboratory

study of comparable

is estimated that a be from 150,000 to

requi re some 800 to

It is not the intent of this chapter to provide a 1st of equipment, but

only to bring out some suggestions. The planning

requires a detailed investigation with a thorough

existing facilities and available references. It minimum investment for the testing equipment will

200,000 U.S. dollars. The building is likely to

1,000 square meters of usable area.

9. Educational Programs

The rapid economic and social progress and development of Nicaragua in

recent years has led to strong demands for comparable growth in the capabilities of its building community; the emergency created by the 1972

Managua earthquake increases these demands. Professional architects and

engineers are strongly motivated to learn the latest practices for earthquake engineering; this is just one of many important and rapidly advancing

areas of building technology. Highly skilled subprof essi onal s and technicians: welders, plumbers, electricians, mechanics, masons, draftsmen, inspectors, etc., are essential to modern building practices. This group is

probably the most lacking in a nation which formerly had a gap between highly

educated and largely illiterate classes of citizens.

Post-graduate education for the professionals is needed in Nicaragua.

There are special difficulties in instituting such a program. The universities appear to be in danger of losing their best qualified faculty to

professional practice for which there is great demand during the emergency.

Formal basic education and technical training are needed to develop subprofessional skills. There may be difficulties in finding equipment and

qualified teachers for subprofessional training programs.

The Organization of American States has sponsored a special training program for construction workers; it achieved such success that the Government

of Nicaragua has requested another, but also identified some problems. The

selection of students must be the responsibility of the management of the

training program; little can be accomplished if the background of students

is too varied. Attention must be given to implementation of new knowledge;

workers returning with new skills, which are not accepted by their supervisors, have gained little.

Establishment of programs for subprofessional training should be accompanied

by a certification process which will assure adequate recognition in responsibilities and in pay, for the successful completion of training.

Modern equipment and facilities are needed for programs of subprofessional

training. The Instituto Tecnico de Capacitacion in Granada, had equipment

and could obtain experienced teachers in Spain. The implementation of their

program was prevented by the lack of a building. This capability should be

investigated in detail, and a government loan considered for construction of

the building, if this program can contribute effectively to the needs of the

building community for subprofessional skills.

The materials testing laboratory, discussed in this report, could provide

an important additional resource in equipment and staff for the support of

programs of subprofessional training.

The universities of Nicaragua, in cooperation with the Nicaraguan Association of Architects and Engineers, should develop programs of post graduate

education for practicing architects and engineers. The shortage of faculty

may be resolved by offering visiting appointments under United Nations or

15
Organization of American States auspices to faculty from abroad. In view

of the opportunities for research and special studies resulting from the

earthquake and reconstruction programs, such a visiting scholar program

would be capable of attracting outstanding faculty.

10. Summary

This review and evaluation of the Nicaraguan building regulatory system has

considered:

o the performance of buildings in the 1972 Managua earthquake

o the emergency building code and the draft building code

o the status of code administration activities of review of

inspection of construction

o current and prospective laboratory facilities for control

quality of building materials

o needs for an institute of building standards charged with

of Nicaraguan building codes and standards

o needs for post-graduate professional education and subprofessional

technicians training programs.

The principal conclusions and recommendations are as follows:

pi ans and

of the

devel opment

and

1 Although human suffering and property losses were severe in the 1972

Managua earthquake, numerous examples of successful performance of

many types of buildings in all parts of the city show that earthquake

resistant construction is feasible and economical for Managua. Future

disasters can be avoided by an effective building regulatory system

requiring land use planning for avoidance of damages caused by faulting and unstable slopes, and earthquake resistant design and construction practices for avoidance of damages caused by ground shaking.

5. The Nicaraguan building community seems able to function with the emer gency code until a new code is developed. However, certain specific

16
deficiencies have been identified which should be corrected promptly

by the proper authorities. No control is being exerted over the

quality of materials; explicit test requirements should be cited in

the code and their performance required by inspection. The scope of

the emergency code should be enlarged by citation of existing standards

to cover structural loadings in addition to earthquakes, and the performance of important aspects of the building in addition to the structure. The code, with adjustment of loadings consistent with local

hazards, should be applied to all important construction in Nicaragua.

6. Inspection services are now provided by engineering students; they are performing well in the emergency. However, for the long range, a permanent body of subprofessional inspectors should be established with

training and salaries appropriate for this important responsibility.

Manuals and check lists are needed for systematic organization of

inspection.

7. A Nicaraguan Building Institute should be established which would include a laboratory for testing building materials and an office of

building standards. The Institute should be independent of the National University since its primary role is technical support of the building regulatory system rather than teaching or basic research, but its

facilities should be conveniently available for liaison and support of

these university programs. The Institute also should be independent

of ministries with direct construction responsibilities since these

may lead to a conflict with its essentially judicial role.

8. The Institute will participate actively in Central American development

of building standards and would be charged with development of building

codes and standards appropriate to Nicaraguan conditions. A principal

initial activity would be the improvement of the emergency building

code. An international organization or international assistance is

particularly important in the next several years during which Nicaraguan professional resources, available to the Institute, are limited

since these resources are largely committed to design, construction,

and regulatory activities related to the reconstruction.

9. The Institute's laboratory for building materials should support control of the quality of building materials and the development of

improved building standards. The laboratory should be capable of all

tests called for in the national building codes and standards, and

should be responsible for accreditation of the private laboratories

which will also provide testing services in support of the building

code and standards.

10. Post-graduate programs for architects and engineers of Nicaragua

should be organized by the universities and the Nicaraguan Association

of Engineers and Architects to disseminate advances in practices to

the professions.

11. Major training programs and facilities should be developed and implemented to increase subprofessional competence in the building com- munity. Appropriate measures for certification of skills and adjustments of salary levels should be made to encourage effective use of

these educational resources.

17
11 References

[1] Matthiesen, R. B., and Knudson, C. F., Strong-Motion Instrumental

Measurements, Managua, Nicaragua Earthquake of December 23, 1972,

Earthquake Engineering Research Institute, pp. 21-25 (May 1973).

[2] Recommended Lateral Force Requirements and Commentary, Structural

Engineers Association of California, 171 Second Street, San Francisco,

California 94105 (1968).

[3] Building Practices for Disaster Mitigation, National Bureau of Standards (U.S.), Building Science Series 46, Wright, R. N., Kramer, S.,

Culver, C. G., editors, 483 pages (February 1973).

[4] Cod i go Para los Construcci ones en el Area del Distrito Nacional, La

Gaceta, Ano LXXVII, No. 15, Managua, Nicaragua (24 January 1973).

[5] Sanderson, R. L., Codes and Code Administration, Building Officials

Conference of America, Chicago, Illinois (1969).
APPENDIX A ITINERARY AND CONTACTS IN FIELD INVESTIGATIONS

This is a day by day account of the principal activities and contacts made

by Ing. Atilano Lamana and Dr. Richard N. Wright in 1973, to gather the

information for this report:

July 9

July 10

•R. N. Wright

Travel to Managua, Nicaragua

Engineer, US/AID

let by Mr. John Kardell, General

•R. N. Wright

Briefing on mission with US/AID staff: Mr. Robert Culbertson,

Director; Mr. Emerson Melaven, Deputy Director; Mr. Craig Noren,

Housi ng

.

July 11 -R. N. Wright

Inspection of housing performance in 1972 earthquake and emergency

housing with Mr. Craig Noren.

A. Lamana

Travel from Santigo, Chile, to Managua, Nicaragua.

July 12 -R. N. Wright and A. Lamana

Briefing with Nicaragua staff of Organization of American States:

Dr. Cesar Cisneros, Representante ; Sr. Manuel Diaz, Subrepresentante; Arq. Julio Ospino.

Inspection of damage and repairs to public buildings: Ing. Jorge

Hayn, Director del Departmento de Construed' ones y Mantenimi ento

de Edificios Publicos, Ministerio de Obras Publicas.

July 13 -R. N. Wright and A. Lamana

Meeting with Ing. Cristobal Rugama, Ministerio de Obras Publicas

to discuss mission.

Meeting with Ing. Humberto Porta, Director Instituto Geografico

to discuss siting studies and earthquake faulting.

Inspection of Laboratorio de Carreteras, Ministerio de Obras

Publicas with Ing. Jaime Icabalceta, Director.

July 14 -R. N. Wright and A. Lamana

Travel to cities of Leon and Corinto to see building conditions

and construction practices.

July 15 -Travel to cities of Masaya and Granada to see building conditions

and construction practices.

July 16 -R. N. Wright and A. Lamana

Inspection of materials testing laboratory, LAMSA, Ing. Carlos

Schutze, Gerente Administrative.

Inspection of laboratories of the Universidad Nacional Autonoma

de Nicaragua, Dr. Abdel Karim, Decano, Facultad de Ciencias and

Ing. Adolfo Diaz, Director, Departamento Ingenieria.

July 17 -R. N. Wright and A. Lamana

Briefing on activities of the Oficina Tecnica de Construed' on Sismica Nacional, Ing. y Dr. Armando Hernandez, Supervisor General; Ing. Luis Bolanos, Deputy.

19
Inspection of materials testing laboratory, NICASOLUM, Ing.

Marcelo Rios, Ingeniero Jefe.

July 18 -R. N. Wright and A. Lamana

Meeting with committee for seismic code review: Ing. y Dr.

Armando Hernandez, Ing. Luis Bolanos, and Ing. Ernesto Carcamo,

Oficina Nacional de Urbanismo; Ing. Christian Icaza, Arquitectura

y Construccion S. A., representing the Association Nicaraguense

de Ingenieros y Arquitectos.

Meeting with Arq

A . , and a member

Eduardo Chamorro, Disenso y Construed" ones , S of the private sector Panel for Reconstruction

July 19 -R. N. Wright and A. Lamana

Meeting with committee for seismic code review (persons noted

above) to confirm perspectives of earlier meeting.

Discussion of procedures for review of plans and inspection,

Oficina Tecnica de Construccion Sismica Naciona; Ing. y Dr.

Armando Hernandez, Supervisor General; Ing. Ernesto Carcamo, Jefe

de Revision; Ing. Noel Zamora, Jefe de Inspection.

Discussion of procedures for building and occupancy permits. Ing

Rolando Hernandez, Jefe, Seccion de Permissos, Oficina Nacional

de Urbanismo.

Discussion of mission and building regulatory system with Ing.

Salvador Lopez, Director, Oficina Nacional de Urbanismo,

Ministerio de Obras Publicas.

July 20 -R. N. Wright and A. Lamana

Discussion of programs for education of subprofessional s such as craftsmen and inspectors with Dr. Cesar Cisneros, OAS.

July 21

July 22

July 23

Briefing of OAS and AID personnel on progress in our mission:

Dr. Cesar Cisneros, Representante , Arq. Julio Ospina, and Srita

Christann Sanchez of OAS, Mr. Robert Culbertson, Director, Mr.

Fred Alvarez, Engineer, Mr. Craig Noren, Housing, and Mr. John

Kardell, Engineer of AID.

Meeting with Nicaraguan architects, engineers and contractors to

discuss perspectives of the building regulatory system: Arq.

Eduardo Chamorro, Disenos y Construcciones S. A.; Arq. Julio

Villa, Director, Sovipe Ingenieros S. A.; Arq. Jose Francisco

Teran, Director, Arquitectos y Ingenieros S. A.; Ing. Frederico

Fielder, Ministerio de Distristro Nacional; Ing. Carlos Santos;

Arq. Roberto Sanson.

R. N. Wright and A. Lamana

Travel to Mexico City, Mexico

R. N. Wright and A. Lamana

Visits to construction sites in Mexico City and State of Mexico

with Dr. Ramon Echenique-Manrique, Invest igador en Ciencia y Technologia de la Madera, Universidad Nacional Autonoma de Mexico

(INAM) . R. N. Wright and A. Lamana

Visit to office of the Organization of American States in Mexico

to arrange contacts in Mexico with persons contributing to a new building code: Sr. Jose Carlos Ruiz, Representante, Arq. Heriberto Allende, Division de Desarrollo Urbano. Reported at U.S.

Embassy, Mr. John Amott, Economics Section.

20
July 24 -R. N. Wright and A. Lamana

Further arrangements with OAS, review of building code provisions,

meeting with Dr. Juan Casillas, Decano, Facultad de Ingenieria,

UNAM.

July 25 -R. N. Wright and A. Lamana

laboratories at

July 26

July 27

July 28

July 30

Inspection of laboratories at UNAM, d code development for Nicaragua and Me

Instituto de Ingenieria: Dr. Emilio

Esteva, Subdirector; Dr. Daniel Resen

Meli .

of work on building

npy-Qonnel of the

UNAM, discussion

Mexico with persoim

Rosenblueth; Ing. Luis

diz, Subdirector; Dr. Roberto

R. N. Wright and A. Lamana

Briefing Mexican office of OAS on progress: Sr. Jose Carlos Ruiz,

Representante ; Arq. Heriberto Allende and Lie. Jorge Videla,

Programa de Desarrallo Urbano.

Development of outline for report, review of proposed code.

R. N. Wright and A. Lamana

Discussion of Nicaraguan building regulatory system with Dr.

Emilio Rosenblueth, Instituto de Ingenieria, and Dr. Ezio

Faccioli, UNESCO, expert in soil dynamics at UNAM.

•A. Lamana

Travel to Guatemala City, Guatemala.

•A. Lamana

Visit to ICAITI, Instituto Centro Americano de I n ves ti gac i on y Technologia Industrial. Meeting with Ing. Gabriel Dengo, Subdirector; Ing. J. Joaquin Bayer, Chief of the Division of

Analysis, Experiments and Tests. Discussion concerned the

coordinative work of ICAITI in standards for Central America.

Visited the laboratories of the Center of Engineering Research

of the University of San Carlos. Meeting with Ing. Emilio

Beltranena, Director, and with Ing. Oscar Asturias on methods

of review, inspection and control of quality of materials in

Guatemal a .

Travel to Managua, Nicaragua.

July 31 -A. Lamana

Met with OAS officials to plan future

Francisco Robleto, Executive Director

for Promotion of Exports.

work. Met with Ing.

of the Nicaraguan Center

August 1 -A. Lamana

A holiday in Managua. Observed damages to buildings in the

center of the city, especially the forms of failure of masonry

wal 1 s . August 2 -A. Lamana

Meeting with Dr. Abdel Karim, Dean of the Faculty of Sciences,

on the building code. Visited with him, the Colonia Centroamerica

for information on methods of repair. Worked in preparation of

lists of equipment for laboratories.

August 3 -A. Lamana

Meeting in the Oficina Nacional de Urbanismo with Ing. Salvador

Lopez, Director, Ing. y. Dr. Armando Hernandez, Supervisor

General, and Ing. Edmundo Davila, Chief of Constructions and

Repai rs .

21
Meeting with Dr. Alejandro Baca in the Camara de la Construed' on

to learn about amounts of production of materials.

August 4 -A. Lamana

Observing damages in subdivisions Bello Horizonte, Salvador ita

and buildings in the center of the city.

August 5 -A. Lamana

Work in preparation of lists of equipment for laboratories.

August 6 -A. Lamana

Visited the Colonia Altmira d'Este accompanied by inspectors from

the Oficina Nacional de Urbanismo, Messrs. Matus and Solozano.

Observed methods of construction of masonry.

Meeting with the Minister of Public Works, Ing. Cristobal Rugama,

together with the representative of OAS, Dr. Cesar Cisneros to

discuss progress in the mission.

August 7 -A. Lamana

Met with the Minister of the National District, Sr. Luis Valle

Olivares to discuss the mission.

Met with

Davila y Oficina NacionalNoel Zamora.

de Urbanismo with Ing. Edmundo

August 8

A. Lamana

Travel to Washington, D. C. August 9 -R. N. Wright and A. Lamana

Visit to the laboratories for testing materials of the National

Bureau of Standards. Meeting with Dr. Robert Crist, Assistant

Chief, Office of Federal Building Technology, to obtain informa

tion on equipment for laboratories.

August 1 0-A . Lamana

Meeting with Arq. Philip Huber, Director, and Arq.

Sanudo of the Programa de Desarrollo Urbano of OAS

them of progress in the work.

Cel esti no

to inform

R. N. Wright and A. Lamana

Work at the National Bureau of Standards on preparation of the

report . August 21-R. N. Wright and A. Lamana

Work at the National Bureau of Standards in preparation of the

report. Meetings with: Ing. J. W. Haverfield, Materials Reference

Laboratories, on methods for inspection of laboratories and

essential laboratory equipment, and Dr. Felix Yokel and Dr. George

Fattal of the Structures Section on problems of resistance of

masonry walls to shearing forces.

22
Presentation of the report on August 21, 1973

Samuel Kramer

Cel es ti no Sanudo

Antonio Quesada

David E. Sarfaty

Osvaldo Bedini

J. A. Van Fleet

Oscar C. Reyes

Thomas R . Call away

Center for Building Technology

National Bureau of Standards

Organization of American States

Organization of American States

Organization of American States

Organization of American States

Inter-American Development Bank

Inter-American Development Bank

Department of Housing and Urban Development

Miss Patsy McCoy provided cheerful and efficient assistance in arrangements

for the study and in typing the draft of the report. Miss Carol Gooden did

excellent work in the final typing.

23
APPENDIX B BUILDING REGULATION FOR EARTHQUAKE RESISTANT CONSTRUCTION

1. THE BUILDING PROCESS AND BUILDING REGULATORY SYSTEM

1 . 1 Objecti ve

The purpose of this paper is to describe the role of standards and of the

building regulatory system in improving the safety and functionality of

buildings and other elements of the manmade environment. Specific attention

is given to standards for mitigation of earthquake hazards, but the procedures for developing design standards reflecting the state of the art of

science and technology and for implementing them through the building

regulatory system are equally applicable to all natural and manmade hazards.

This paper was drafted for the U .

S

./Ni caraguan Reconstruction Technical

Seminar held in Managua, June 20-21, 1973, cosponsored by the Domestic and

International Business Administration, U.S. Department of Commerce, and the

members of the Nicaraguan private sector who agreed to participate. It takes

a general view of procedures for building code enforcement, legal authorities

for building regulations, and procedures for the development and implementation of standards. Hopefully, this description will be adaptable to a wide

variety of situations for building regulation. This description is based on

a major recent review of building practices for disaster mitigation (!)— .

It must be emphasized that earthquake resistant construction is entirely

practicable with good building practices. Earthquakes, hurricanes, floods,

etc., are natural hazards; they are not natural disasters. They are extreme

environments which we know will recur from time to time. Disaster denotes

the extensive losses of life and property which can occur from the chain

reaction of failures resulting from man's neglect of these natural hazards

in his building practices.

Interfaces of the building regulatory system with the building process are noted. The organization and administration of the building regulatory

system are described. Examples are given of systems which have been particularly effective, and others which have been particularly ineffective,

in providing earthquake resistant construction.

1/

Numerals in parentheses refer to entries in the list of references

24
1.3 Building Process

A simplified, schematic diagram of

1, which is taken from reference 2. study and program analysis, decide

be located, how much space will be

space are required. The principal

and the architect. It is important

the building process is shown in figure

The early phases, the feasibility

such matters as where the building will

provided and what characteristics of the

actors in this activity are the owner

to obtain breadth of professional

inputs in programming. Specialists such as the engineering geologists may

guide in the site selection; the structural engineer can assist in selection of a structural scheme well adapted to site conditions and intended

use

.

The design phases, schematic design and design development, are concerned

with the development of a solution meeting the requirements developed in

programming. Principal participants in design include the architect,

structural engineer, mechanical engineer, foundation engineer, etc.

The contracting phase, involving preparation of contract documents and

bidding or negotiation for selecting the contractor, requires preparation

of detailed working drawings and specifications by the design team or potentia

contractors and the preparation and evaluation of contractors' offers. The

construction phase involves the actual construction and its surveillance. As

discussed below, the design team should play an important role in this phase.

The final part of the building process occupancy has, as principal actors,

the persons using the building, those who maintain or remodel it, and,

hopefully, if we are to learn from our past mistakes, some surveillance by

the planning and design team which allows them to evaluate the success of

their design concept.

1.4 Building Regulatory System

Major interactions of the building regulatory system with the building

process also are shown in figure 1. The principal elements of the building

regulatory system are: (1) the building regulations denoted as "code", and

(2) the regulatory agency or agencies which enforce and interpret the codes.

The codes speak directly to certain aspects of the building and the building process :

o land use, defining the natural and manmade environments,

o design, controlling the performance of the building in the natural

and human environments,

o construction, controlling how the design is implemented,

o occupancy, controlling how the building is used, maintained, re- modeled, or removed.

The usual interactions of the

process are shown in figure 1. planners and designers during

that these regulations are com reviews the planning and desig

designer's conception are made

This interaction is denoted "a after any necessary modificati

compliance with the design dur

processes of inspection, and s tinued after construction to a

building regulatory system and the building

The codes themselves are referred to by the

the programming and design stages to assure

plied with. The building regulatory system

n when appropriate documents describing the

available to the building regulatory system,

gency" in figure 1. Following approval,

on, the building regulatory system promotes

ing construction by field enforcement. These

ometimes of evaluative review, may be con- ssure appropriate occupancy.

The responsibilities of the regulatory system are summarized in figure 2.

The building regulatory system is responsible for development and mainten- ance of the building code (here considered to include land use, zoning,

25
subdivision, and other regulations), the process of examination and approval

of plans which assures their compliance with the code, and field enforcement

which assures that the construction and occupancy are in accord with the

code and plans.

2. STANDARDS FOR BUILDING

2.1 Types of Standards

A standard is commonly defined as "that which is established by authority

as a rule for measuring." Since the term is used by many with differing

shades of meaning, let us define some terms for use herein:

o Specification: a stated rule for measurement

o Standard: A broadly accepted specification

o Code: a legal requirement for application of a standard

Note these terms are distinguished by the process of promulgation. A stand

ard is textually like a specification, but it has been accepted through an appropriate process by a group which is recognized to issue standards. A code is issued by a lawmaking body.

Standards may

they present.

be classified

Sanderson ( 3

)

in accord with the type of rule

notes the following classes:

for measurement

o Engineering practice, such as a method for predicting the strength

of a beam

o Material, such as a broadly accepted definition of a type of cement

o Test method, such as a procedure for stating the strength of con- crete

Note that standards of these categories can be referred to in a code.

Standar

Wright

mance s in q u e

s

meets t focuses

def i ni t often a not mee

they ar determi

t i v e st

an o p t

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cri pti v (5).

ds m

(4)

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proc

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standards should

Both have their

of the desired a user to say: "Th

nservi ceabi 1 i ty f eful statements t ted. It is quite

s on reinforcing

f the col umn . Id

ildings (such as the attributes de

s .

not be seen as the antithesis of prescriptive

place. Performance standards are essential for

ttributes of the building. It is most meaninge building must have less than 1 percent probarom earthquake per year." Prescriptive stando the designer or to the builder of exactly

clear that this stress is to be computed as P/A

bars will be separated by no more than 1/4 of

eally, prescriptive standards for particular

reinforced concrete frames) will be calibrated

sired for particular classes of occupancy, such

26
2.2 Land Use Planning

Land use plans provide standards which substantially affect the safety of

buildings from earthquakes or other hazards. Wiggins, et a 1 . , (6) review

the state of the art of land use planning for disaster mitigation and

provide a guide to literature in the area. The major elements of land use

pi anni ng are :

o The general plan, which is a prescriptive standard for a geographical area describing how land use is to develop.

o Zoning regulations, which describe the conditions for land use for

various purposes. One set of zoning regulation may be applied to a variety of general plans.

o Subdivision regulations prescribe in detail how land is to be used

when subdivided for a specific purpose.

Planning for disaster mitigation may take two approaches. One is exclusionary, totally preventing certain land uses in certain areas. This approach

is appropriate when these land uses would be clearly undesirable. Another

approach is microzoning in which the land use plan defines the intensity of

natural hazards for specific areas. The microzoning approach allows con- siderably greater flexibility in land use. Land use is not arbitrarily

restricted but results from an economic balance between the benefits and

costs of rational land use.

Mi crozona ti on for earthquakes will account for intensity of ground shaking,

hazards of permanent ground movements such as landslides and fault displacements, and recurrence intervals for earthquake induced flooding and wave action. The forces of ground shaking usually can be accounted for in

all types of buildings and occupancies. The other effects are considerably

more critical; if their hazards are high, exclusionary zoning is usually

required. Microzoning for wind effects is similar. Wind velocity, as affected by topography and surface roughness, can be accounted for rationally in building design. Wind induced storm surges sometimes can be accounted for by design; otherwise, these areas may be avoided for construction.

Building exclusion from flood plains is a common form of land use regulation

However, mitigation of flood damage also can be provided in design. Volcanic effects require attention in regional land use planning, and usually

require exclusionary planning.

2.3 Consensus and Industry Standards

Recal 1 i n acceptan

i ndustry

be accep

Ameri can fabri cat

standard

est i n c

1

sumers a consensu

any gove

and the

Testi ng

test met

variety

design 1

g that

ce by

stand

ted by

I n s t i ion an will

u d i n g f fecte

s stan

rnment

Ameri c and Ma

hods . of sta

oads f

a s some

ards

a s tute

d er

be a

i ndu

d by

dard

al b an N teri

The

ndar

or b

tanda

cons

i s i p e c i f of S ecti o ccept

stry , the

orga

ody,

ati on

al s p Amer

ds in

u i 1 d i

rd is

t i t u t e

n the

i c i n d teel C

n of s ed by

the p proces

n i z a t i are th

al Sta

romul

g

i c a n N

c 1 u d i n ngs , a

d i s t i n g d body,

group a ustry o onstruc

tructur

a group

rof essi

s or pr ons , ne

e Ameri

ndards

ates st

a t i o n a 1 g test

nd \/ery

u i s h e d the d c c e p t i r trad

ti on s al s te

repre

ons us oduct

i t h e r can So

I nsti t andard

Stand

method

compl

from

i s t i n ng th

e ass

p e c i f el fo

s e n t i ing t stand

one o ci ety

ute . s dea

ards

s , en ex pr

a s cti o em

.

oci a

i cat

r bu

ng t he s ardi

f wh

for

The

ling

Inst

gi ne oduc

p e c i f i n betw

Indus

t i o n .

i on f o

i 1 d i n g he gen

tandar

zed .

i c h is

Testi

Ameri

with

i tute

e r i n g ts sue

cation

een con try sta

An exa

r the d s. Ac

era! pu

d , and

The maj

affi li ng and

can Soc

both ma promul g practi c

h as mo

by i sens ndar

mpl e esig

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teri

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is the

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rials

for

al s and

a wide

uch as homes .

The process for promulgation of a consensus performance standard is shown

in figure 4; a similar process is used for prescriptive standards. Usually

the standard is drafted by a vitally concerned sponsoring group. Often

this group represents the industry or profession using the standard. The

27
standard is reviewed by a committee representing all affected parties

elements are important in the review:

Two

o Technical correctness, does it reflect the state of the art of

technol ogy?

o Performance levels, is the performance called for adequate and yet

not requiring wasteful overinvestment in unneeded performance?

Generally the process of review includes a publicly recorded vote. Substantial negative votes will preclude promulgation of the standard; all negative

votes must be specifically considered and resolved.

2.4 Structural Design Standards

From a performance viewpoint, structural design standards pertain to one or more of the following objectives in disaster mitigation:

o avoid human suffering

o avoid property loss

o preserve essential functions

To a the

dati

si en stat

sei s by t tion

resp

and

1 oad

c h i e v limit

on of

t 1 os

es pe

mi c 1 he dy

. En onse

as a ings

e th

sta

the

s of

rtai

oads

nami

ergy

and mean

for

ese obj

tes (7)

system

f u n c t i n to st

, parti

c respo

absorp

thereby

s for p which p

ecti

: u

; fu

onal

ruct

cul a nse tion

mai rese

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ves ,

1 tim

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ity.

ural

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of t

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the

ate

onal

Th

des

tent

he s impo

ning

g n

1 OSS

d e s i g limit

limit

ese co

i g n s t

i on mu tructu

rtant

f unct

f e saf

es and

ner stat

sta

nsi d anda

st b re a as a iona

ety

los

must

es in

tes i erati

rds f

e giv

nd to mean H ty

under

ses o

give ex

vol ve s nvol ve ons of

or any

en to 1 mechan

s f or r or a v o

i

p 1 i c i ome p

a per

perf o type

i m i t isms

e d u c i ding

reat

i o n a 1

t attention to

ermanent degramanent or tran- rmance and limit

of loading. For

states generated

of energy absorpng dynamic

property loss,

(but infrequent)

ity are tolerated

Stru mane

prop

seve

spec

gene

base

faci

trum

evol

out

ment

ctura

e by

orti o ri ty

i f i c ral n d , an

1 i t i e with

ution

where

s i n

1 design criteria must provide for the desired level of perforconsi stent selection of design loadings, response analyses, and

ning procedures. The state of the art for definition of loading

is discussed on a sei smol ogi cal basis by Algermissen (9) and for a building site by Donovan (10). Newmark and Hall (11) describe the

ature of the principles upon which earthquake resistant design is

d consider the development of design procedures for structures,

s, and components with emphasis upon the use of the design specdeformation. Pinkham (12) reviews the

current seismic design criteria, and points

earthquakes illustrate needs for improveaccount for inelastic

of an experience with

experiences in recent

criteria.

In the establishment of structural design criteria the decision is made on how the building should behave for various levels of earthquake excitation.

Then, both analytical procedures and proportioning criteria can be focused

on assuring the desired behavior under the design conditions. Bresler (13)

describes how structural elements respond to the cyclic, inelastic deformations induced by earthquakes. Available laboratory and field experience

has defined standards conducive to avoidance of collapse in earthquakes.

28
Further standards development and research will provide better guides to

maintenance of important functions, reduction of property damage, and more economical designs.

It is more challenging to establish effective standards for the safety of

existing buildings. Buildings constructed under earlier standards may not

provide the performance levels now required by society. However, since

either their strengthening or removal is very expensive, special attention

to their safety is appropriate. McClure (14) describes available knowledge

and current standards for survey and evaluation of existing buildings.

2.5 Standards for Nonstructural Systems

Much of the hazard to life, much of the property loss, and much loss of

function results from damages to building furnishings and equipment in

earthquakes or other natural hazards. Ayres and Sun (15) describe experiences with building furnishings and equipment in recent earthquakes and

recommend standards and details for mitigation of these losses.

The safety of furnishings and equipment provides a special problem in

standards writing since the design and installation very rarely involves

the structural engineers who tend to be most conscious of earthquake

effects. It must be recognized that buildings will move in earthquakes.

Furnishings and equipment must be designed to accept the anticipated motions

without damage and to hold together under the shaking the building will

undergo .

The failures of utilities and industrial equipment cause substantial losses

in earthquakes and other natural disasters. Enforcement of standards for

these facilities has not traditionally come under the authority of the

building regulatory system even though the consequences of failures of

these systems are equally relevant to public safety. Descriptions of these

failures (16, 17) suggest that design standards comparable to those applied

for buildings or for the furnishings and equipment of buildings, should be

developed and enforced.

2.6 Building Codes

The building code is essentially the collection of standards whose application is required by law. The history of the development of the building

regulatory system in the United States, Baseler (18), has led to a large

number of building codes and code authorities. The principal collections

of building standards are the so-called model codes (the Basic Building

Code of the Building Officials and Code Administrators International Inc.,

the Uniform Building Code of the International Conference of Building

Officials, the Southern Standard Building Code of the Southern Building

Code Congress, and the National Building Code of the American Insurance

Association). For the first three, the standards are generated by a consensus-like process in which affected professional and industrial groups

can recommend standards and speak for or against their adoption. However,

the voting for adoption is limited to the building officials who are the

members of these organizations.

The individual States of the United States of America possess the primary

constitutional authority for building regulations. The States have joined

together in the National Conference of States on Building Codes and Standards (NCSBCS) for coordinated efforts in development of standards and code

administration procedures. Statewide building regulations have been established by 23 States. In many instances, this amounts to uniform, Statewide

implementation of one of the model codes.

Federal agencies establish standards for the buildings they construct or

use themselves, or the buildings which are Federally assisted in construc29
tion, for example, by a Federally guaranteed mortgage. Federal standards

are published for review and comments by all affected organizations, interests, or individuals before the standards are implemented. Conflicts may

be resolved by informal discussions or legal processes.

The development of a building code for a local government or a State involves

complex interactions of many parties as noted in figure 5.

2.7 Housing Codes

Housing codes control the conditions of occupancy of buildings. To date,

these codes have been concerned with public health under essentially normal

conditions of use. When consideration is given to the relationships between normal conditions of use and the hazards which may arise in the event

of an earthquake, it is evident that attention should be given to seismic

risks in the development of housing codes.

3. ADMINISTRATION OF CODES AND STANDARDS

3.1 Functions of the Building Regulatory System

The principal functions of the building regulatory system are related to

the participants in the building process in figure 2. The totality of

activities of the building regulatory system is somewhat broader:

o generation and maintenance of standards and codes

o administration of codes

review of plans

inspection of construction

testing or approval of testing of materials and components

inspection of conditions during occupancy

emergency measures for public safety

o licensing of professionals involved in the building process

o education of the staff of the building regulatory system

The organization and administration of the building regulatory system must

provide for the effective conduct of these functions. There are a variety

of organizations possible for these functions. In the following sections

some United States experiences are noted.

3.2 Organization of the Building Regulatory System

Technical standards for inclusion in building codes follow generally the

process of development sketched in figure 3. The group developing the

standards language may be an industrial, professional, or governmental

organization with particular concern for the specific technical area. All

of these groups have strong commitment to the building process. Generally,

one or more will react promptly when a need for improved standards becomes

evident in the building community. The appropriate role of the building

regulatory system is to assure that there is standards generating activity

where needed, and to provide, solicit, or endorse appropriate financial

support for the generation of standards.

Building code administration is part of the police power of the government.

Sanderson (3) notes that it effectively implements the required legal

authority only when it reports directly to the chief executive, focuses all

enforcement for land use, building, and housing codes in one agency, and

has this enforcement activity as the sole function of the agency.

These activities require a well qualified staff sufficient in number to:

maintain the quality of the building code, evaluate all planned construction, and oversee activities during construction. Substantial investment

in the building regulatory system is essential to the general public bene30
fit. The sources of revenue for the building regulatory system are discussed by O'Bannon (19). It is appropriate to charge some of the costs to

the direct users through charges for building permits and inspections.

However, a substantial part of this activity, as well as that for maintaining the building regulations, provides benefits to the general public and

should be supported from the general revenue. It is particularly important

not to assess the builder for the costs of inspection and testing. Under

these circumstances, the inspector and testing laboratory come to feel they

work for the builder and identify with his concerns rather than those of

the occupant and general public.

3.3 Experiences for Seismic Regions

As described by Pinkham (12) seismic design criteria and provisions for

their implementation have evolved from actual experiences with earthquakes.

The west coast of the United States has been the location of its most

frequent exposure to damaging earthquakes; United States design criteria

wery largely arise from California experience. However, the introduction

of nuclear reactors, and public concern for the secondary hazards which

would arise from a earthquake-damaged reactor, have encouraged high-level

scientific and professional concerns with earthquake hazards and earthquake

design criteria for all regions of the United States, Newmark and Hall

(11). Present activities in the Federal Cooperative Program on Building

Practices for Disaster Mitigation (1) are focused on development of a new generation of seismic design standards from the extensive research and

experiences of the last decade.

The Field Act of California (16) has been shown by actual earthquake experience to provide an effective approach to mitigation of earthquake hazards.

The requirements of the Field Act are not generically different from those

of the building regulatory system of figure 2; rather it requires by law

that these activities be carried out effectively.

o Plans and specifications must be prepared by a licensed architect

or structural engineer.

o The plans and specifications are submitted to a specific State

department for review and approval prior to contracting for con- struction.

o A full-time resident inspector must assure compliance with the

plans and specifications. Moreover, the construction is to be

supervised by an architect or structural engineer.

o Verified reports shall be submitted by the architect, engineer,

contractor and inspector certifying that all work complies with

the approval document.

o The State agency makes field inspections during the progress of

construction.

o Any violation of the Act or false statement is a felony.

In contrast to this successful experience, every earthquake shows failure of

buildings as a result of practices which are known to be inadequate for

earthquake resistant construction. These include:

o critical facilities which failed at the time they are most needed

by their community as a result of failure to require higher levels

of performance for such facilities.

o unbraced frame structures which have sufficient flexibility and

ductility to avoid structural collapse, but whose motions are so large as to induce extensive nonstructural damage with concurrent

hazard to life, loss of property, and loss of functionality.

o shear wall systems which are stiff enough to reduce nonstructural

damage, but show enough damage in earthquakes of limited duration

to call into question their safety for great earthquakes.

31
collapses which arise from inadequate lateral force resistance and

ducti 1 i ty

.

major structural damage from inadequate diaphragm systems to provide

for horizontal transfer of lateral forces.

inadequate detailing of structural members to provide for toughness

and energy absorption.

lack of attention to providing definite clearances between elements

which will move relative to one another or strong connections between elements which should move together.

complex framing schemes which lead to concentration of deformations

and local failures.

hazards to life or property from failures of nonstructural elements,

nonstructural elements which have acted structurally to reduce the

resistance or energy absorption of the structure,

inadequate anchorage of equipment.

additions and modifications of buildings which lacked the attention

given earthquake resistance in the original design.

There is no perfect safety. Reduced, but never zero, risks of loss from

earthquakes or other hazards is achieved only for increased investment.

The Structural Engineers Association of California (20) estimates the

following increases in building costs (not including land, site work, or tenants improvements) to increase lateral force resistance from the nominal

levels supplied where strong winds or earthquakes are not considered to the

level needed in the highest seismic zone.

One and two story wood frame

One to two story brick or concrete block

Four story and up brick or concrete block

Reinforced concrete

Steel frame

2 percent

8 percent

10 percent

5 percent

3 percent

Thes

basi

when

cann

crib

bene

illu

and

of t perc

acti

tion

i nve

e re

c sc

it

ot b es t fit

mi na Ware

he t ent

v i t i cos stme

prese

heme

i s no

e est

he mi

s t u d i ting

(22)

otal

i n th es ca

t i s nt ha

nt a

i s w

t.abl i cro

es r to p poi

1 ife

e op

rri e of t

s gr

verage

el 1 ada

The pol

shed co and mac

e q u i r e d ut firs

nt out

cycle c e r a t i o n

d out i he orde

eat lev

values, costs can be lower when the architect's

pted to lateral force resistance and much higher

icy on appropriate levels of earthquake performance

nsidering first cost alone. Kunreuther (21) desro economic considerations involved in the costs/

to establish optimal levels of performance. It is

t costs in a total lifecycle perspective. Hattis

that for a typical office building that 2 percent

ost is involved in the initial construction, 6 and maintenance, and 92 percent in the costs of

n the building. An additional 10 percent construcr of 0.002 of the total lifecycle cost; this small

erage in mitigating losses.

3.4 Emergency Activities

The building regulatory system also has a primary responsibility for the

public safety during an emergency such as the occurrence of an earthquake.

McClure (14) describes activities which must be conducted during an earthquake emergency. The building regulatory system may have primary responsibilities in:

o rescue of persons trapped in damaged buildings

o assessment of the safety of buildings for emergency occupancy

o assessment of building damages to guide emergency allocations of

governmental funding

o criteria for repairs of damaged buildings following the earthquake

emergency

o updating codes and code enforcement practices in light of the

1 essons 1 earned .

32
It is a major responsibility of the building regulatory system to be ready

to carry out its emergency functions, to learn from the emergency, and to come forth from it with an improved building regulatory system. McClure

provides counsel on all these factors.

4. SUMMARY AND RECOMMENDATIONS

4.1 The Professional Perspective

Building standards and the building regulatory system cannot be considered

to make automatic the attainment of excellent buildings. This objective

can only be achieved through the participation of skilled and responsible

individuals in all facets of the building process. Standards and the regulatory system do provide guidance to these individuals and protect them

from the unfair competition of the less scrupulous.

4.2 Requirements for Producing Earthquake Resistant Construction

Earthquake resistant construction is achieved only if the activities shown

in figure 1 are carried out effectively. This requires:

o proper siting and conception of the building with the aid of land

use planning standards in the programming phase

o proper design with the aid of standards for the loads, response

analysis and proportioning for the structure and nonstructural

el ements

o careful review by the building regulatory agency to assure that the

land use planning and design standards were correctly employed

o careful implementation of the plans in construction with inspection

by skilled representative of the building regulatory agency and the

designers

o occupancy of the building under the guidance of the housing code to

maintain its initial safety

4.3 Needs for Standards for Earthquake Resistant Construction

Experiences in recent earthquakes indicate that where current design standards are effectively applied, earthquake hazards are substantially mitigated. The most important immediate need is for the effective implementation

or recognized good practices.

The seventy-one major recommendations in reference 1 speak to many needs

for improved standards for earthquake resistant construction. Only a few

major points can be noted here. The risk inherent in the design standards

should be stated explicitly so that all parties in the building process

know where they stand and so that reduced risks can be achieved where

desired. The last ten to fifteen years have seen much research in earth

and engineering sciences and much experience with earthquakes. Much of

this new knowledge is not yet available in design standards and methodologies to the design professions. A major program of updating seismic design

codes is underway under the sponsorship of the Cooperative Program on Building Practices for Disaster Mitigation.

4.4 Needs for Improvements in the Regulatory System

The organization of the building regulatory system is discussed in Section

3.2. Unfortunately, the ideal organization of the building regulatory

system is rarely achieved. It calls for:

o focus of all code enforcement activities in one agency

o that the chief of this agency have direct responsibility to the

chief executive of the level of government responsible for building

regulations

33
o that code enforcement be the sole function of this agency

Experience with California schools constructed under the Field Act shows

that this organization of the building regulatory system is effective. It should be uniformly adopted.

34
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REFERENCES

[I] Building Practices for Disaster Mitigation, Wright, R., Kramer, S., and

Culver, C, editors, Nat. Bur. Stand. (U.S.), Bldg. Sci. Ser. 46, 474

pages (Feb. 1973). Available from Superintendent of Documents, U.S.

Government Printing Office, Washington, D. C. 20402, (SD Catalog No.

CI 3 . 29/2:46, $5.30)

[2] Rowland, G. A., and Gallagher, N. E., Performance Standards--Thei r Compatibility with the Building Regulatory System, Nat. Bur. Stand. (U.S.),

8 pages (1972) .

[3] Sanderson, R. L., Codes and Code Administration, Building Officials

Conference of America, Chicago, Illinois (1969).

[4] Wright, J. R., Performance Criteria in Building, Scientific American,

224 , No. 3, pp. 17-25 (March 1971).

[5] Dikkers, R. D., Coordinated Evaluation System Project (CES), Model

Documentation for Building Regulation, Nat. Bur. Stand. (U.S.), Tech.

Note 775 (May 1973).

[6] Wiggins, J., et a!., Land Use Planning and Natural Disaster Mitigation,

Building Practices for Disaster Mitigation (Ref. 1), pp. 139-178.

[7] Wright, R. N., and Ang, A. H. -S., A Consistent Basis for Functional

and Ultimate Criteria, Performance Concept in Building, Nat. Bur. Stand.

(U.S.), Spec. Publ. 361, 1, pp. 181-190 (Feb. 1972).

[8] Sharpe, R., Kost, G., and Lord, J., Behavior of Structural Systems

under Dynamic Loads, Building Practices for Disaster Mitigation (Ref.

1 ) , pp. 352-394.

[9] Algermissen, S., The Problem of Seismic Zoning, Building Practices for

Disaster Mitigation (Ref. 1), pp. 112-125.

[10] Donovan, N., Earthquake Hazards for Buildings, Building Practices for

Disaster Mitigation (Ref. 1), pp. 82-111.

[II] Newmark, N., and Hall, W., Procedures and Criteria for Earthquake

Resistant Design (Part II), Building Practices for Disaster Mitigation

(Ref. 1 ), pp. 209-236.

[12] Pinkham, C, Procedures and Criteria for Earthquake Resistant Design

(Part 1), Building Practices for Disaster Mitigation (Ref. 1), pp. 188-

208.

[13] Bresler, B., Behavior of Structural Elements, Building Practices for

Disaster Mitigation (Ref. 1), pp. 286-351.

[14] McClure, F., Survey and Evaluation of Existing Building, Building Practices for Disaster Mitigation (Ref. 1), pp. 395-426.

[15] Ayers, J., and Sun, T., Criteria for Building Services and Furnishings,

Building Practices for Disaster Mitigation (Ref. 1), pp. 253-285.

[16] Lew, H. S., Leyendecker, E. V., and Dikkers, R. D., Engineering Aspects

of the 1971 San Fernando Earthquake, Nat. Bur. Stand. (U.S.), Bldg. Sci.

Ser. 40, (December 1971 ) .

[17] Schiff, A. J., and Yao, J. T. P., Response of Power Systems to the San

Fernando Valley Earthquake of 9 February 1971, Center for Large Scale

Systems, Purdue University, (1972).

40
[18] Baseler, P., Approaches to Implementation, Building Practices for Disaster Mitigation (Ref. 1), pp. 63-81.

[19] O'Bannon, R. E., Building Department Administration, International Con

ference of Building Officials, Whittier, (1973).

[20] Report of the Ad Hoc Committee on Costs of Design for Earthquakes,

Structural Engineers Association of California, (Sept. 1970).

[21] Kunreuther, H . , Values and Costs, Building Practices for Disaster Miti

gation (Ref. 1), pp. 41-62.

[22] Hattis, D. B., and Ware, T. E., The PBS Performance Specification for

Office Buildings, Nat. Bur. Stand. (U.S.), NBS Report 10527, p. B8.

41
APPENDIX C HOUSING PERFORMANCE IN THE 1972 MANAGUA EARTHQUAKE

This reports a survey of the performance of modern housing developments in

Managua during the 1972 earthquake. Most of the developments are low or moderate cost financed through the Banco de la Vivienda de Nicaragua,

however, performance is also reported for a traditional area and a few

upper income housing developments. The purpose of this report is to show,

by Nicaraguan experience, that it is feasible and economical in developing

or developed countries to construct buildings which will resist severe earthquake shaking. All of these housing developments were competitive in

the Nicaraguan housing industry. Some performed very well; a more detailed

study of the plans and material properties for these units will be required

to quantify the characteristics which assured good performance. Some

performed badly, in many instances the reasons for this bad performance

were clearly indicated in visual inspection of the damages. The performance, good and bad, is described and illustrated in the inspection summaries which follow.

The writer collected some information for this report on December 30, 1973,

and January 3, 1973, in company with Mr. Samuel Kramer, Chief, Office of

Federal Building Technology, Center for Building Technology, National

Bureau of Standards, and Ing. Raul Amador, Departamento de Construcciones y

Mantenimiento de Edificos Publicos, Ministerio de Obras Publicas, Nicaragua,

These earlier investigations [1]!/ focused principally on larger public

buildings. Most of the material presented here was obtained in a survey

conducted on July 11, 1973, in company with Mr. Craig Noren, Foundation for

Cooperative Housing, with USAID mission, Managua, Nicaragua. Mr. Noren

provided the information on the characteristics of the housing developments

which is listed in Table 1.

The damages described herein were caused principally by very intense ground

shaking throughout the whole area of the map in figure 1. A peak horizontal acceleration of 0.39g was recorded [2] at the ESSO refinery just west

of the Laguna Asososca at the left of figure 1. This is among the highest

intensities of ground motion ever recorded for an earthquake [3]. Since the

surface breakage due to the earthquake faulting [4] appeared along the

lines noted near the center of figure 1, it is likely that the intensity of

ground motion for all the housing developments approached or exceeded the

values measured at the ESSO refinery. The seismic intensity contours re- ported by Hansen and Chavez [5], support this inference.

The housing units are relatively stiff, high natural frequency buildings

which would be quite susceptible to damage from the relatively intense but

relatively short duration earthquake which occurred in Managua. Therefore,

housing units which performed well in the Managua earthquake would be

likely to perform well if subjected to severe earthquake shaking in other

parts of the world.

The primary conclusion to be drawn is that much of the performance was very

good. In spite of the severe shaking, structural damage was in many instances negligible or light and the units remained habitable. Severe damages

and collapses were observed, but these damages can be attributed generally

to poor details of construction or deficiencies in the materials. It would

1/

Numbers in brackets refer to entries in list of references

42
not have been expensive to avoid these defects. Little additional material

or time is required to execute connection details well. Proper control of

material quality does not add substantially to construction costs.

Good building practices in Managua resulted in housing units which withstood the severe earthquake successfully. Those which failed to perform

well could have if inspection of plans and construction, and testing of

materials had assured that the dimensions, details, and qualities of materials were appropriate for a zone of high seismic risk. Table 1 and the

inspection summaries which follow illustrate that the poorly performing

units were not systematically more economical than those which performed

well. There is clear evidence that earthquake resistant construction is

feasible and economical for Nicaragua or any other nation with comparable

resources available to the building community.

43
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S45
Housing Performance

Type of Housing

Size

Date of Construction

Financi ng

Location

LAS BRISAS

Inspection Date

Inspected by

11 July 1973

Craig Noren

R. N. Wright

middle income

one story

1970

FHA/CABEI

A on figure 1 Most of the units use light weight corrugated metal or asbestos roofs on timber framing. Walls appear to be masonry, concrete blocks or tile, reinforced with columns and bond beams. Damage to these units was wery limited,

occasional light cracking at most, not enough to reveal details of construction, figure 2; store construction in the colonia uses reinforced concrete

block, figure 3.

Near the south of the development, we found a row of houses which included a type using poured, probably precast, concrete panels and concrete panel

roofs alternately, figure 4, with the type described above. The concrete

panel types had all failed and had been abandoned while those of the reinforced masonry type were in good condition and in use. The failures were typically separation of panels at joints, figures 5 and 6; the joint details

were minimal ties, perhaps just what was needed for construction loads.

Some interior panels, notably around showers, figure 7, had fallen. This is

evidence of strong snaking at Las Brisas and demonstrates the importance of

careful connections in panel systems.

Housing Performance

Type of Housing

Size

Date of Construction

Financing

Location

COLONIA FRANCISCO MORAZAN

Inspection Date: 11 July 1973

Inspected by : Craig Noren

R. N. Wright

lower income

one story

1967

INVI (Instituto Nicaraguense de la Vivienda)

B on figure 1 These units had light corrugated roof systems; some with cast-i n-pl ace con crete walls with #2 undeformed reinforcement and some with reinforced con- crete block walls. Figures 8, 9, and 10 show a unit with some cracking,

most units had no such visible damage.

Housing Performance

Type of Housing

Si ze Date of Construction

Financing

Location

BARRIO M0NSEN0R LEZCANO

Inspection Date: 11 July 1973

Inspected by : Craig Noren

R. N. Wright

mi xed

varied,

various

one and two stories

probably after 1931

C on figure 1 Taquezal performance, figure 11, ranged from shaken-off plaster and roof

tile to complete collapse. Wooden slab buildings showed no damage. Masonry

and concrete frame construction ranged in performance from light cracking to

collapse, figure 12 and 13. The closeup of figure 14, shows poor performance

of unreinforced masonry.

46
Figure 2: Las Brisas, no apparent damage to typical house.

Figure 3: Las Brisas, reinforced block masonry construction.

47
Figure 4: Las Brisas, alternate concrete panel type (failed) and

reinforced masonry (in use) houses.

Figure 5: Las Brisas, detail of panel separations at connections.

48
Figure 6: Las Brisas, displaced roof

panel

.

Figure 7: Las Brisas, joint where

interior partition was displaced.

49
Figure 8: Colonia Francisco Morazan, cracking representative of

greatest observed damage.

Figure 9: Colonia Francisco Morazan, cracked

wall

.
Figure 10: Colonia Francisco Morazan, opened joint at corner.

51
i^SJ&r

^*^w

1

1 K'fe

gj

ii i

I H

.I U11 1

»

iHdP jria ***

—x.

: ^-—'—

•xTv^'iF

J^^l

Figure 11: Barrio Monsenor Lezcano, most taquezal severely damaged

or collapsed.

Figure 12: Barrio Monsenor Lezcano, varied performance of masonryconstruction.

52
'•>'<*!&%;%%

Figure 13: Barrio Monsenor Lezcano, mix of sound and collapsed buildings.

Figure 14: Barrio Monsenor Lezcano, close up of damaged masonry.

53
Housing Performance

Type of Housing

Size

Date of Construction

Financing

Locati on

COLONIA MANAGUA

Inspection Date

Inspected by

1 1 July 1973

Craig Noren

R. N. Wright

lower income,

one story

1960

INVI

D on figure 1

sel f-hel p

This is an ai ded-sel f-hel p housing project [6]. The corners and wall panels

of full height are tilt up poured reinforced concrete, masonry block infills

are used below windows, roofs are corrugated metal or wood framing. Performance is generally good, the infilled, unkeyed masonry panels tended to

crack and sometimes fall in out-of-plane flexure. The corner panels often

showed a diagonal crack at about 2/3 height. An example of greater than

average damage appears in figure 15. Occupants were pleased with the housing performance and showed pride of construction; they reported shaking had

been severe enough to damage plumbing fixtures. Added rooms including

second stories, figure 16, performed quite well. Nearby taquezal construction was severely damaged.

Housing Performance

Type of Housing

Si ze Date of Construction

Financing

Locati on

COLONIA MAXIMO JEREZ

Inspection Date: 11 July 1973

Inspected by : Craig Noren

R. N. Wright

lower middle income

one story

1967

INVI

E on f i gure 1 These are light roofed, one-story houses with two types of walls. One type

uses a reinforced concrete end frame with members about 6 in square, perhaps

cast in place, with precast panels inside the frame, figure 17. Similar

construction occurs in Colonia 14 de Septiembre. These walls were substantially damaged, figure 18 and 19. Some construction joints between frame

members had no continuity, the precast panels separated because of inadequate anchorage. The other type of wall in unframed concrete at corners,

enough to expost reinforcement and the full thickness of wall. These damages appear more easily repairable. In general, houses in this colonia had

light to substantial, but repairable, damage.

Housing Performance

Type of Housing

Si ze Date of Construction

Financing

Locati on

ALTAMIRE D'ESTE

Inspection Date

Inspected by

11 July 1973

Craig Noren

R. N. Wright

upper middle income

varied, one or two stories

1969 and later

F on figure 1

In general, the substantial houses in this area survived well with some light damage. The collapsed reinforced masonry house, figure 21, designed

and occupied by an engineer, shows a stenciled sign blaming the builder for

the failure.

54
Figure 15: Colonia Managua, damage limited to cracking in poured concrete corner.

Figure 16: Colonia Managua, additions, even of second stories,

survived.

.- .-.-_• .-vST 55
«D :

4

i

i—

i

v

1

Figure 17: Colonia Maximo Jerez, less damaged frame-panel units.

Figure 18: Colonia Maximo Jerez, separation

of frame and panels.

56
Figure 19: Colonia Maximo Jerez, damage to interior and exterior

panels.

Figure 20: Colonia Maximo Jerez, unframed units showed some cracking at corners.

57
t

l!

Si***

V /'*>'

i^>'is ^*» *

Figure 21: Altamira d'Este, the stencil is the owner-designer blaming the builder

58
Housing Performance

Type of Housing

Size

Date of Construction

Financing

Location

BOSQUES DE ALTAMIRA

Inspection Date: 11 July 1973

Inspected by : Craig Noren

R. N. Wright

middle income

one story

1970 and later

CABEI with HIGO

G on f i gure 1

In this area the intensity of shaking was sufficient to topple free standing,

one meter high masonry walls. These houses use corrugated metal roofs on steel framing set into the exterior and interior masonry walls. These walls

are tile reinforced with bond beams and columns. Many houses show little or

no damage, a few are severely cracked as a result of poor details of reinforcement.

Housing Performance

Type of Housing

Size

Date of Construction

Financing

Location

LOS ROBLES

Inspection Date

Inspected by

11 July 1973

Craig Noren

R. N. Wright

upper middle income

varied, one or two stories

1960

H on figure 1 Damage varied from none visible to collapse. A collapsed two-story house of

tile walls reinforced with concrete bond beams and columns shows poor anchorage of reinforcing; the dimensions and details were not apparent for the

collapsed first story structure, figure 22. Roofing had been salvaged; it

appeared to have been tile on a wood frame. The range of performance from

negligible damage, figure 23, to collapse indicates the importance of good

building practices.

Housing Performance

Type of Housing

Size

Date of Construction

Financing

Locati on

C0L0NIA LUIS S0M0ZA

Inspection Date: 11 July 1973

Inspected by : Craig Noren

R . N . Wright

lower middle income

one story

1970

INVI

1 on f i gure 1

The walls are concrete block reinforced by concrete bond beams and columns.

The interior cross wall is structural with a reinforced crown beam, figure

24. Roofing is asbestos cement on timber purlins. Damage varied from none

to light cracking, figures 25 and 26. Intensity was enough -to collapse free

standing masonry walls and lightly reinforced masonry houses in the nearby

Barrio Ducuali, figure 27.

59
Figure 22: Los Robles, collapsed two-story

house, second floor on ground.

Figure 23: Los Robles, generally good condition of neighborhood.

60
Figure 24: Colonia Luis Somoza, structural

interior walls.

Figure 25: Colonia Luis Somoza, generally good condition of

houses.

61
I*

Figure 26: Colonia Luis Somoza, light cracking of blocks.

Figure 27: Barrio Ducuali, collapsed house with roof salvaged.

L^M^

62
Housing Performance

Type of Housing

Size

Date of Construction

Financing

Location

COLONIA NICARAO

Inspection Date

Inspected by

11 July 1973

Craig Noren

R. N. Wright

Roof

and

The

a fi

thi r

i s w fore

meti

tanc

rei n abou

pres

deta

s are tile, concr

el d c d of

eak s ement

cal ly

e. T force

t 50

sed u

i 1 s a

corruga

were se ete wal 1 o n n e c t i o these un

i nee 3 #

i n the

, i t i s he units

ment, fi

percent

n h a p p i n e ppeared

ted m en . s are

n to

its b 3 bar

full

diffi

with

gures

of th

ss wi

d e f i c

lower middle income

one story

1960-1963

INVI

J on figure 1

etal on timber framing. Two types of walls, concrete

Sound units with concrete walls are shown in figure 28.

3 in thick, perhaps using precast corner elements with

the panel below window. The front walls of about one- ulged in out-of-plane flexure, figure 29. The corner

s with less than 1 in effective depth are the reinheight, figure 30. These damages are repairable cos- cult to achieve proper, greater than original, resistile walls appeared to have cavities grouted without

31 and 32. Although no collapses of these were seen,

ese walls were severely damaged. Some occupants exth the performance, indeed the quality of construction

i e n t

.

Housing Performance

Type of Housing

Size

Date of Construction

Financing

Locati on

COLONIA 14 DE SEPTIEMBRE

Inspection Date: 11 July 1973

Inspected by : Craig Noren

R . N . Wright

lower middle income

one s tory

1964

INVI

K on f i gure 1 Performance is generally better than in the adjacent Colonia Nicarao, figure

33. Most walls are concrete block reinforced with bond beams and columns,

figure 34, some use end frames as in Maximo Jerez, figure 35, apparently

with concrete panel walls; roofs are corrugated asbestos cement. There is

damage to most homes, typically wall flexure out of its plane, figure 36,

perhaps due to unsatisfactory mortar.

63
Figure 28: Colonia Nicarao, less damaged units,

Figure 29: Colonia Nicarao, bulging of front walls,

64
Figure 30: Colonia Nicarao, close up of corner reinforcement.

Figure 31: Colonia Nicarao, damaged grouted tile construction.

J

65
Figure 32: Colonia Nicarao, damaged grouted tile construction.

Figure 33: Colonia 14 de Septiembre from Colonia Nicarao, damage

lesser in former colonia.

66
Figure 34: Colonia 14 de Septiembre, concrete block house with light

damage.

Figure 35: Colonia 14 de Septiembre, cracked and repaired house of

type like Maximo Jerez.

67
Figure 36: Colonia 14 de Septiembre, concrete block house with flexural cracking.

68
Housing Performance

Type of Housing

Size

Date of Construction

Fi nanci ng

Location

VIVIENDO DE MI HERMANO

Inspection Date: 11 July 1973

Inspected by : Craig Noren

R. N. Wright

lower income

one story

under construction 1972

L on figure 1

These

ded in

beams

cement

37. L than a most o col umn

to the

togeth connec

ted si

p r i a t e

are

the runn

roo ater mom

f th

s, f bea

er

.

tion

neefor

cons

gro

ing

f pa

al f ent

e un

i gur

ms s Som

had

the

reg

truct

und t one w nel s orce

resi s rei nf

e 38.

i nee

e tee

litt

units

i ons

ed o hrou

ay o span

resi

tant orce

Ma

the

bea

1 e s wer

of s

f a gh a

n to

ni ng

stan

con

d ma

ny a conn

ms p tren

e no tron

syste

cast

p of

betw

ce co necti

sonry

sbest

e c t i o ulled

gth i t occ

g lat

m wit

- i n - p the c een b mes f on to

wal 1 os ro

n was off

n she

upi ed

era!

h pr

1 ace

ol urn earns rom

the

s; t of p

i na the

ar,

; th

fore

e t e n s i footi

ns , la

, and

the i m beams

hey we anel s dequat

col umn figure

e syst

e

.

oned concrete columns imbedng, prestressed inverted tee

rge corrugation asbestos

infill masonry walls, figure

bedment of the column rather

The earthquake shook out

re not anchored to beams or were broken by the fasteners

e to cause the frames to move

s since the beam to column

39. Human losses were limiem as designed seems inapproHousing Performance

Type of Housing

Size

Date of Construction

Financing

Locati on

PROYECTO PILOTO

Inspection Date

Inspected by

11 July 1973

Craig Noren

R. N. Wright

lower middle income

one story and two story

1969

INVI

M on figure

PRIMERO DE MAYO

Inspection Date

Inspected by

11 July 1973

Craig Noren

R. N. Wright

Type of Housing

Si ze Date of Construction

Financing

Location

lower income

one story

1972

INVI

N on figure 1

The row units use light corrugated asbestos roofs and reinforced concrete or masonry walls, figures 43 and 44. There was not enough damage to clearly

reveal the details of the construction. The structural performance in the

earthquake was excellent.

69
Figure 37: Viviendo de mi Hermano, frame and wall failures as seen January 3, 1973.

Figure 38: Viviendo de mi Hermano, collapsed

wa 1 1 s

.

70
Figure 39: Viviendo de mi Hermano, sheared column.

71
Figure 40: Proyecto Piloto, view of one and two story units.

Figure 41: Proyecto Piloto, sound structural condition of two story

units.

72
Figure 42: Proyecto Piloto, damage limited to loss of eave trim panels

73
Figure 43: Primero de Mayo, units show no damage.

Figure 44: Primero de Mayo, close up of an entrance.

74
Housing Performance

Type of Housing

Size

Date of Construction

Financing

Locati on

CIUDAD JARDIN

Inspection Date

Inspected by

11 July 1973

Craig Noren

R. N. Wright

middle class

one story

1961

CABEI

on figure 1 Shaking here next to the Aduana fault was strong enough to topple free

standing masonry walls. These houses with light roofs and reinforced

masonry walls showed no collapses; damage ranged from light to severe with

most units in the lightly damaged group, figures 45 and 46. Blocks were loosened in some walls, suggesting substandard mortar, figure 47. Other

walls cracked due to poor details of reinforced.

Housing Performance BELLO HORIZONTE

Inspection Date

Inspected by

30 Dec. 1972

Raul Amador

Sam Kramer

R. N. Wright

Type of Housing

Size

Date of Construction

Financi ng

Locati on

middle i ncome

one story

1969

CABEI

P on f i gure 1

These are single and duplex units with cast- i n-pl ace reinforced concrete

walls and precast prestressed channel shaped roof panels, figure 48. Dwelling units are approximately 20 ft wide by 40 ft deep, walls are 4 in thick,

roof panels are 8 ft wide and 22 ft long with 12 in flange height and 2 1/2

in slab thickness. Roof panels are intended to be attached to walls by

welding at four corner pads. At best, weld size was about 3/16 in, 2 in in

total length; many welds were spots or omitted, figure 49. In most units

roof panels broke their anchorage and moved, sometimes enough to fall off

the wall and into the unit, figure 50. Where welds were stronger the wall

or slab often is broken around the anchorage of its connection pad, figure

51. Other damages to the walls were slight.

These show graphically

inadequate connections

how a basically sound precast system can fail through

75
Figure 45: Ciudad Jardin, repairs of cracking and broken panels.

Figure 46: Ciudad Jardin, localized damage, failure of free standing

walls.

76
Figure 47: Ciudad Jardin, crack patterns suggesting weak mortar,

77
Figure 48: Bello Horizonte, the precast roof channels have slid off walls,

December 30, 1972.

Figure 49: Bello Horizonte, lack of connection of roof to wall in duplex

unit, December 30, 1972.

78
Figure 50: Bello Horizonte, weld broken and roof panel cracked at con- nection, December 30, 1972.

Figure 51: Bello Horizonte, walls cracked at connection of roof panels,

December 30, 1972.

79
REFERENCES

[1] Wright, R. N., and Kramer, S., Building Performance in the 1972 Managua

Earthquake, National Bureau of Standards (U.S.), Technical Note 807, 150

pages (1973).

[2] Matthiesen, R. B., and Knudson, C. F., Strong-Motion Instrumental

Measurements, Managua, Nicaragua Earthquake of December 23, 1972, Earthquake Engineering Research Institute, pp. 21-25 (May 1973).

[3] Lew, H. S., Leyendecker, E. V., and Dikkers, R. D., Engineering Aspects

of the 1971 San Fernando Earthquake, National Bureau of Standards (U.S.)

Building Science Series 40, 419 pages (December 1971).

[4] Brown, R. D., Jr., Ward, P. L., and Plafker, G., Geologic and Seismologic Aspects of the Managua, Nicaragua Earthquake of December 23, 1972,

U.S. Geological Survey, Geological Survey, Professional Paper 838, 34

pages (1973).

[5] Hansen, Francisco, and Chavez, Victor M., "Isoseismal Maps of the

Managua, December 23, 1972 Earthquake," Managua Nicaraguan Earthquake

of December 23 , 1972 , Earthquake Engineering Research Institute, San

Francisco, pp. 104-114 (November 1973).

[6] Colonia Managua, Ideas and Methods Exchange No. 58, Office of International Affairs, Department of Housing and Urban Development, Washington, D. C, 15 pages (June 1962).

[7] Proyecto Piloto de Vivienda en el Istmo Centroameri cano , Comite Interi nsti tucional sobre Vivienda y Desarrollo Urbano, Secretaria General

de la Organizacion de los Estados Americanos, Washington, D. C., 65

pages (1972).

80
NBS-114A (REV. 7-73)

U.S. DEPT. OF COMM. BIBLIOGRAPHIC DATA

SHEET

1. PUBLICATION OR REPORT NO. NBS TN-885

2. Gov't Accession

No.

3. Recipient's Accession No.

4. TITLE AND SUBTITLE

A Technical Review of the Nicaraguan Building

Regulatory System

5. Publication Date October 1975

6. Performing Organization Code

7. AUTHOR(S)

Richard N. Wright, and Ing. Atilano Lamana

8. Performing Organ. Report No.

9. PERFORMING ORGANIZATION NAME AND ADDRESS

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

10. Project/Task/Work Unit No. 460.00

11. Contract/Grant No.

12. Sponsoring Organization Name and Complete Address (Street, City, State, ZIP)

National Bureau of Standards

Organization of American States

Agency for International Development

fDepartment of State)

13. Type of Report & Period Covered Final

14. Sponsoring Agency Code

15. SUPPLEMENTARY NOTES

Library of Congress Catalog Card Number: 75-600078

16. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bibliography or literature survey, mention it here.) This report on the Nicaraguan Building Regulatory System has been prepared under the

auspices of the Organization of American States and the United States Agency for International Development. It presents an overview of the building regulatory system in

Nicaragua; its activities in review of designs, issuance of building permits, inspection of construction, control of quality of materials, and issuance of occupancy permits. The technical bases for these activities are the building code and standards,

the laboratory facilities for control of the quality of building materials, and the

processes for development and application of codes and standards. Recommendations

address the status and development of this system and its technical bases.

The losses in the December 23, 1972, Managua Earthquake provided dramatic evidence

of the need for effective implementation of good building standards. Repetitions of

these tragic losses elsewhere in Nicaragua and in a reconstructed Managua are certain

unless a good building code is developed and adopted, its use and design by architects

and engineers enforced by careful review of designs, and the implementation of these

designs by the builders assured by inspection of construction and testing of building

materials. A summary and critical review of U.S. building regulatory practices for areas with severe natural hazards is presented in Appendix B for guidance in building

regulatory system planning and development. A survey of housing performance in Managua

is presented in Appendix C to illustrate that earthquake resistant construction is

feasible and economical for Nicaragua and other nations with comparable resources.

17. KEY WORDS (six to twelve entries; alphabetical order; capitalize only the first letter of the first key word unless a proper name; separated by semicolons)

Architecture; building; building codes; building design; disaster mitigation; earthquakes; engineering; environmental hazards; housing; inspection and testing; safety.

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