(b) Measurements of specimens. Thickness measurements, when
required, shall be made with a suitable micrometer. Al)
other dimensions shal] be made with a commerically obtainable
measuring tape and all dimensions reported to the nearest
1/16 inch.

Procedure of Test

5. (a) The scaffold or shoring tower or shore to be tested shall be
erected in such a manner as to simulate field conditions and
aligned vertically so that it is not out of plumb more than
1/8" in three feet. No greater attempts should be made to
adjust the components concentrically then would be expected
in actual use.

(b) The load shal] be applied directly on the load bearing member
or members by use of load transfer beams or cross head of
testing machine; or directly by hydraulic jacks in an approved
testing apparatus or fixture.

Duration of Test

6. The scaffolding tower or shore shall be subject to increasing
loads until the ultimate load is reached.

Speed of Testing

7. (a) The allowable limits for rate of loading on scaffolding
towers shall be not less than 5,000 lbs. per minute nor
more than 10,000 lbs. per minute.

(b) The allowable limits for rate of loading on Post Shore shall
not be less than 1,000 lbs. per minute nor more than 2,000
lbs. per minutes.

{c). The rate of loading in each test shall remain constant.

Types of Tests

8. (a) Shoring leg loading shall consist of frames erected into
towers composed of four (4) vertical legs’ with a normal
bracing, base plates, and/or adjustment screws. When
adjustment screws are used they shall be extended equally
on the top and equally on the botton;, but top and bottom
extensions need not be the same. All four load bearing
legs shall be subjected to simultaneous loading until the
ultimate load is reached by the weakest leg. Tests
according to this method are "A" series tests.

10


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4.

Certification

1 certify that the above described test was performed in accordance
with the applicable provisions of the Procedure for Compression Testing
of Welded Frame Scaffolds and Shoring Equipment as published by the
Scaffolding, Shoring & Forming Institute, Inc.

Attach Sketch of Test

14 ¥U.S. G.P.0.:1993-301-717:80357


APPENDIX:
SCAFFOLDING, SHORING, AND FORMING INSTITUTE
TEST PROCEDURE


L

IL.

SYSTEMS CERTIFICATION

All factory-fabricated components of vertical shoring towers used to support bridge construction
shall be either tested or analyzed to determine that it is a certified system capable of supporting a
specific allowable design load. Bridge shoring layouts may utilize multiple-load capacity towers (c.g.
20 kips (89 KN), 100 kips (445 KN), etc.).

Each shoring tower class shall be tested, analyzed, and marked in accordance with the following
procedures:

A. The testing of vertical shoring towers shall be accomplished by one of the following
methods:

1 A representative vertical shoring tower that consists of all structural components
manufactured by one source shall have been tested in accordance with the
Scaffolding, Shoring, and Forming Institute (SSFI) test procedure (see appendix) to
determine allowable loads.’ These allowable loads shall be certified by the single
source manufacturer through ‘his representative to the bridge contractor.

2, A vertical shoring tower system that consists of components obtained from several
manufacturers shall have been tested in accordance with the SSFI test procedure to
determine allowable loads. These allowable loads shall be certified by the supplier
(equipment owner) of the intermixed equipment to the bridge contractor.

3. ‘An alternate to 1.A.2. (above): A representative vertical shoring tower(s) of intermix
component systems shall be on-jobsite tested by the contractor following the SSFI
test procedure with the exception that on-site loading may be substituted for the use
of laboratory or specially designed test machines, The supplier of the intermix
components or the contractor, if he is the owner of the equipment, shall have the
on-site engineer certify the test procedure and determine the allowable design loads
using the SSFI recommended factors of safety.

B. The analysis of the system shall be accomplished by a complete three-dimensional structural
analysis. In many cases, some test loading may be warranted to determine joint parameters
to be used in conjunction with the three-dimensional analysis, The manufacturer, supplier,
or contractor who uses the analysis method for determination of allowable loads shall certify
these allowable loads to the bridge contractor.

This analysis method may also be used for single source suppliers.

(on The marking of the system for certification shall consist of the following:

1, The manufacturer of all new components manufactured after the date of this
publication shall place on cach component a marking indicating his name as
manufacturer. In case LA.2. and LA3. (above), the supplier and/or owner of the
equipment shall mark each componcat with their own identification, indicating that
the components that they have supplied have been tested to determine the
allowable loads that they are certifying.

CONTRACTOR'S ENGINEER DOCUMENTATION
A. A bridge shoring layout is to be submitted by the contractor, and must include the following:

1 Shoring tower components identification by the manufacturer and/or supplier
and/or contractor.


TABLE OF CONTENTS
Section No, Page No,

L SYSTEMS CERTIFICATION

eosesnesenes 1

II, CONTRACTOR'S ENGINEER DOCUMENTATION

TI, FORMWORK 3

APPENDIX: SCAFFOLDING, SHORING, AND FORMING INSTITUTE
TEST PROCEDURE .

eesrsseesense 5



HNR-10/11-93 (1M) QE


I.

f. Check that when two or more tiers of frames are used, each shall be
braced to at least one adjacent frame.

g While checking the cross braces, also check the locking devices to ensure
that they are all in their closed position or that they are all tight.

h. Check each upper adjustment screw or shore head to ensure that it is in
full contact with the formwork. If it is not in contact, it should be adjusted
or shimmed until it is.

i. Check to see that the obvious mistakes of omitting joists, using the wrong
size ledger, or timber placed flat have not been made. Check the print to
see that the lumber used is equal to that specified on the shoring layout,
Check the general formwork scheme to make sure that it follows good
standard practice for formwork.

j. If the shoring layout specifies exterior bracing for lateral stability, check to
see that this bracing is in place in the locations specified on the drawing.
Check to make sure that the devices that attach this bracing to the
equipment are securely fastened to the legs of the shoring equipment. If
tubing clamps are used, make sure that they have been properly tightened.

If devices for holding timber have been used, check to see that a sufficient
number of nails have been used to hold the bracing securely to the frame

legs.
FORMWORK

Reference Guide Design Specification for Bridge Temporary Works, Publication No. FHWA-RD-93-
032, Federal Highway Administration, Washington, DC, January 1993.

Reference ANSI A10.9 Concrete and Masonry Construction.


QO

Publication No. FHWA-RD-93-033
November 1993

Certification Program for
Bridge Temporary Works

©

US.Department of Transportation
Federal Highway Administration

Research and Development
Tumer-Fairbank Highway Research Center
6300 Georgetown Pike

McLean, Virginia 22101-2296


Stringers or ledgers - members which directly support the
joists, usually wood or steel load-bearing members.

FRAME OR PANEL* - The principal prefabricated, welded structural unit
in a tower.

HORIZONTAL SHORING - Metal or wood load-carrying beams of fabricated
trussed section used to carry a shoring load from one bearing point,
column, frame, post, or wall to another.

JOISTS - See Formwork

LIFTS OR TIERS* - The number of frames erected one above each other
Tn a vertical direction.

LIVE LOAD - The total weight of workmen, equipment, buggies, vibrators,
and other loads that will exist and move about on the scaffold or
shoring equipment.

LOAD BEARING MEMBER - Any component of a scaffold or shoring structure
which 1s directly subjected to load.

LOCKING DEVICE - A device used to secure the cross brace to the frame
or panel.

POST SHORE or POLE SHORES* - Individual vertical member used to
support Toads.

a. Adjustable Timber Single Post Shore - Individual wooden
timers used with a fabricated clamp to obtain adjustment
and not normally manufactured as a complete unit.

b. Fabricated Single Post Shores - Type 1; Single all-metal
post, with a tine adjustment screw or device in combination
with pin and hole adjustment or clamp.

Type I1; Single or double wooden post members adjustable
for a metal clamp or screw and usually manufactured as a
complete unit.

c. Timber Single Post Shores - Wood timber used as a
structural member for shoring support.

RE-SHORING - A system used during the construction operation in which the
~~ ortatnal shores are removed and replaced in a sequence planned to
avoid any damage to partially cured concrete.

SAFE LEG LOAD - The load which can safety be directly imposed on the
frame leg. (See Allowable Load).

SCAFFOLD LAYOUT - A design diagram for scaffolding.

SHOCK LOAD - Impact of material such as the concrete as it is released or
dumped during placement.

SHORE HEADS - Flat or formed metal pieces which are placed and centered
on vertical members.

Ne


Ne

January 31, 1986
Publication No. S102

Recommended Procedure
for
COMPRESSION TESTING OF WELDED FRAME SCAFFOLDS AND SHORING EQUIPMENT
Scope

1. This procedure is intended to cover the compression testing of equip-
ment used for scaffolding and vertical shoring.

Definition of Terms

2. The definition of terms below, relating to the compression testing of
equipment used for scaffolding and shoring should be considered as
applying to the terms used in these methods of compression testing.

ACCESSORIES - Those items other than frames, braces, or post shores used
to Facilitate the construction of scaffold and shoring.

ADJUSTMENT SCREW = A leveling device or jack composed of a threaded screw
‘and an adjusting handle used for the vertical adjustment of the
scaffolding, shoring and formwork.

ALLOWABLE LOAD - The ultimate load divided by factor of safety.
BASE PLATE - A device used to distribute the vertical load.

COUPLER OR CLAMP* - A device for locking together the component parts of
a tubular metal scaffold.

COUPLING PIN - An insert device.used to connect lifts or tiers vertically.

CROSS BRACING - A system of members which connect frames or panels of
scaffolding or shoring laterally to make a tower or continuous
structure.

DEAD LOAD SHORING - The load of forms, stringers, joists, reinforcing rods,
and the actual concrete to be placed.

EXTENSION DEVICE - Any device, other than an adjustment screw, used to
Obtain vertical adjustment of shoring or scaffolding equipment.

FACTOR OF SAFETY - The ratio of ultimate load to the allowable load.

FORMWORK - The material used to give the required shape and support of
poured concrete, consisting primarily of:
Sheathing - material which is in direct contact with the concrete
such as wood, plywood, metal sheet or plastic sheet.
Joists - Members which directly support sheathing.


The allowable tower leg load requirements.

Verification of shoring leg loadings so that the sills, cribbing, or piles can be
designed of sufficient size to support the shoring loads as determined by jobsite soil
Specification of internal shoring bracing furnished by the manufacturer.

Specification of any external bracing (guys, etc.) required by the supplier and
furnished by the contractor.

B. Prior to installation the contractor shall document that:

4.

5.

All components contain manufacturer, supplier, or contractor’s identification.

Each component is in satisfactory condition, ic. not bent, broken, distorted, welds
not cracked, and parts not corroded. Surface rust is acceptable.

Moving parts operate (locks work, jack handles turn, etc.).
Coupling pins must effectively align the frame or panel legs.

Pivoted cross braces must have center pivot securely in place.

c. Prior to load application:

1,

Each shoring tower.per I. (above) shall contain the components as specified by the
certification as to manufacturer/supplier. The certification shall include the name
of the company that is certifying the system.

a Check to see that there is a sound footing, or sill, under every leg of every
frame on the job. Check also for possible washout duc to rain.

b. Check to make certain that all base plates or adjustment screws are in firm
contact with the footing or sill. All adjustment screws should be snug
against the legs of the frame.

« Obtain a copy of the shoring layout that was prepared for this specific job.
Make sure that the spacings between towers and the cross brace spacing of
the, towers do not exceed the spacings shown on the layout. If any
deviation is necessary because of field conditions, consult with the engineer
who sealed the drawings for his approval of the actual field setup.

d. Check for plumbness in frames in both directions. The maximum
allowable tolerance for a frame that is out of plumb is 1/8 inch in 3 ft
(3.175 mm in 0.9 m). The total tower frame leg out of plumb dimension
shall not exceed the diameter of the frame leg. If the frames exceed this
tolerance, bases must be adjusted until the frames are within the tolerance.

e Check for gaps between the lower end of one frame and the upper end of
another frame. Gaps indicate that one adjustment screw must be adjusted
to bring the frames in contact. If this adjustment does not eliminate the
gap, then it indicates the frame is out of square and must be replaced.


PREFACE

Following the collapse of the Route 198 bridge over the Baltimore/Washington Parkway in 1989, the
Federal Highway Administration (FHWA) established the temporary works research program. The program
was guided by a task group established by the FHWA. The task group was comprised of representatives
from the FHWA, the American Association of State Highway and Transportation Officials, the
Transportation Research Board, the American Road and Transportation Builders Association, the Associated
General Contractors, the American Society of Civil Engineers, and the Scaffolding, Shoring, and Forming
Institute (SSFI). This certification program was prepared by the Shoring Engincering Committee of the SSFI
at the request of the FHWA.

The certification program was developed to ensure that the equipment used at a jobsite is identifiable and
in a condition to perform the intended task. The document addresses all factory-fabricated components of
vertical shoring towers used to support bridge construction. It provides for testing vertical shoring towers
that have structural components manufactured by one source and components that are intermixed from
several manufacturers.

The program also addresses the proper documentation, inspection, and certification needed by the
equipment owner and the contractor’s engineer prior to placing concrete.

Na,


(b)

(c)

(d)

(e)

Post Shores shall be tested individually at their minimum
and maximum heights and at every foot throughout their
operating range. The shores may be tested in both a braced
condition and an unbraced condition with the individual

test data displayed as a graph showing allowable load

versus overall height with the manner of bracing, if any,
clearly indicated. Loading shall be continued until ultimate
load is reached. Tests performed according to this method
are "B" series tests.

Extension devices - shall be positioned in or upon the legs

of the shoring and tested in the manner outlined in paragraph
8 (a). The extension devices may be tested extended from

the top, bottom or both ends of the legs, and also in a braced
or unbraced condition. The devices shall be tested at their
maximum and minimum height and at every foot through their
operating range with the individual test data displayed as

a graph showing allowable load versus extended length and the
manner of bracing,-if any, clearly displayed. Tests performed
according to this method are "C" series tests.

Welded Frame Wall Scaffolds - Welded frame wall scaffolds shall
be tested one (1) frame wide and two (2) cross brace lengths
Jong. The frame scaffold components shall be erected into the
above configuration composed of six (6) vertical legs with
normal manufacturer's recommended bracing, and with base plates
or adjusting screws on the botton. The six (6) legs of the test
configuration are to be loaded to the scaffold’s anticipated
allowable leg load and held at that value. Loading shall be
continued on the two legs of the center fram until the ultimate
load of these two legs is reached. The ultimate load of the center
frame legs shal] be the ultimate Jeg load for the welded frame
scaffold system. Tests performed according to this method are
"D" series tests. .

Scaffold Component Testing - All load-bearing individual

scaffold components shall be tested independently to obtain

their ultimate load. When components are supported by other
scaffold members, a test fixture of design similar to these
supporting members shail be used to support the components being
tested to assure that the test load can be transferred to the
adjacent members. All components shall be tested to ultimate load
and horizontal being components shall have their ultimate load as
well as their total center deflection recorded. Tests performed
according to this method are "E“ series tests.

Witness of Test

9.

All tests must be witnesses by @ reputable independent testing

laboratory, University, or a registered Professional Engineer, who

must attest that the test was performed in accordance with
applicable provisions of this standard.

i


TEST SUMMARY FORM

Tested by: Date of Test

Test Number

Component Tested

Type of Test (Machine. » or Apparatus )
a. Series (A), (B),.(C), (0), (E)
b. Number of Tiers
c. Adjustment Beyond Leg
Top 5 ’ >
Bottom > ’ >
d. Extension Beyond Leg
Top. . 5 5
Bottom_ , ,
e. Extension, (Top ) (Bottom, )
(Braced » or Unbraced y
f. Ultimate Total Test Load
g.° Utlimate Load - Each Leg:
, ’ , (Average )
h. Ultimate Shore Load

i.

Ultimate Ledger Load ;

Witness to Test

Company Representative

Independent Representative

Other Witness

Other Witness



Ke

Technicat Report Documentation Page

1. Report No. 2. Government Accession No.

FHWA-RD-93-033

3. Recipient's Catalog No.

4. Title and Subtitie
CERTIFICATION PROGRAM FOR BRIDGE TEMPORARY WORKS

5, Reoort Date
November 1993

"6: Performing Organiizaiion Code |

7. Author(s)
Shoring Engineering Committee

9. Performing Organization Name and Address
Scaffolding, Shoring, and Forming Institute, Inc.
1300 Sumner Avenue
Cleveland, Ohio 44115-2851

70. Work Unit No. (TRAIS)
3D1b

11, Contract or Grant No.

13. Type of Report and Period Covered

12. Sponsoring Agency Name and Address.
Office of Research and Highway Operations R&D
Federal Highway Administration
6300 Georgetown Pike
McLean, Virginia 22101-2296

Final Report
April 1990 - December 1992

14, Sponsoring Agency Code

15. Supplementary Notes
FHWA Program Manager for Bridge Temporary Works:

Sheila Rima) Duwadi

16. Abstract

Following the collapse of the Route 198 bridge over

Parkway in 1989, the FHWA established the temporary works research program.

The program was guided by the Scaffolding, Shoring,
formed by the FHWA.

bridge site.

This report is a series of reports produced under this program.

reports in this series are:

The objective of this report is to develop a
certification program aimed at the supplier of falsework equipment to the

the Baltimore/Washington

and Forming Task Group as

The other

FHWA-RD-91-062
FHWA-RD-93-031
FHWA-RD- 93-032
FHWA-RD- 93-034

Synthesis of Falsework, Formwork, and Scaffolding
for Highway Bridge Structures

Guide Standard Specification for Bridge Temporary
Works

Guide Design Specification for Bridge Temporary
Works

Construction Handbook for Bridge Temporary Works

17. Key Words

Falsework, formwork, shoring,
temporary structures, certification

18. Distribution Statement

No restrictions. This document
is available to the public through
the National Technical Information

program. Service, Springfield, Virginia 22161.
19. Security Classd. (of this report) 20. Security Classif. (of this page) 21. No. of Pages| 22. Price
Unclassified Unclassified 18

Form DOT F 1700.7 (8-72)

Reproduction of completed page authorized



FOREWORD

This study is part of the Federal Highway Administration’s Temporary Works
Research Program, conducted as a result of the falsework collapse of the
Route 198 bridge over the Baltimore/Washington Parkway, Maryland. This report
was developed by the industry to act as a certification program for
manufactured falsework systems supplied to bridge construction projects. This
certification program is aimed at the supplier of equipment to bridge sites,
be that the manufacturer or the contractor. It is also intended for the State
highway agencies to use in developing their own specification. This program
will be of interest to bridge owners, contractors, and manufacturers and
suppliers of falsework components to bridge projects.

Additional copies may be obtained from the National Technical Information
Service, 5285 Port Royal Road, Springfield, Virginia 22161.

Thomas +
Director, Office of
Engineering and Highway
Operations Research and
Development

NOTICE

This document is disseminated under the sponsorship of the Department of
Transportation in the interest of information exchange. The United States
Government assumes no liability for its contents or use thereof.

The contents of this report reflect the views of the authors who are
responsible for the facts and the accuracy of the data presented herein. The
contents do not necessarily reflect the policy of the Department of
Transportation.

This report does not constitute a standard, specification, or regulation. The
United States Government does not endorse products or manufacturers. Trade or
manufacturers’ names appear herein only because they are considered essential
to the objective of this document.


SHORING LAYOUT - A design drawing prepared prior to erection showing
arrangement of equipment for shoring.

SILL OR MUD SILL* - A footing (usually wood) which distributes the
Vertical Toads to the ground or slab below.

SPAN - The horizontal distance between posts, columns, or upright support
members.

STRINGERS. OR LEDGERS* - see formwork.

TESTING APPARATUS OR FIXTURE - A special purpose device fabricated for
the express purpose of testing scaffolding and shoring.

TESTING MACHINE - A compression testing machine of a type usually found
in Universities, Colleges, and reputable Testing Laboratories.

TIMBER STRESSES - Stress-grade lumber conforming to recommended tables
Tn “Wood Structural Design Data Book", by National Lumber
Manufacturers Association, Washington, 0.C.

TOWERS - A composite structure of frames, braces and accessories.

TUBE AND COUPLER EQUIPMENT - An assembly used asa load-carrying
Structure consisting of tubing or pipe which serves as posts,
braces, and ties, a base supporting the posts, and special
couplers which serve to connect the uprights and join the various
members.

ULTIMATE LOAD - The maximum load which may be placed on a structure
before its failure due to buckling of column members or failure
of some component.

Calibration of Testing Devices

3. (a) The device used to determine loads applied shall be calibrated
and certified either immediately before or after the testing
by a reputable testing laboratory.

(b) Testing machines used for compression testing shall be calibrated
in accordance with ASTM Specification £4 of current revision
during the preceding 12 month period.

Test Specimens

4. (a) Scaffold and shoring components shall be selected at random
from inventory and shall exhibit approximately the same
variations in measurements as would be expected from random
sampling including mill tolerances on thickness of various
members.

*(These terms may be used synonymously. )


Report of Test Results

10. Test resuits shall be reported on Form A (see attached) including
drawing of test setup with the following:

(a) Ultimate Total Test Load

{b) Ultimate Leg Load or Component Test Load as Applicable
(c) Type of Test

(d) Laboratory

(e) Witness

ssfi
revised 8/85
Jpb/itj