10CUEE CONFERENCE PROCEEDINGS
10th International Conference on Urban Earthquake Engineering
March 1-2, 2013, Tokyo Institute of Technology, Tokyo, Japan

BUILDING MONITORING EARTHQUAKE RESPONSE NETWORK IN LIMA

Patricia Gibu 1), Carlos Zavala 2), Ricardo Proaño3), Luis Lavado3) and Lucio Estacio4)1) Associate Professor, Associate Researcher
2) Professor, Chief Laboratory of Structures,
3) Assistant Professor, Earthquake Engineering Dept,4) Assistant Professor, Assistant Researcher Laboratory of Structures
CISMID, Civil Engineering Faculty, Universidad Nacional de Ingeniería, Perúpgibu@uni.edu.pe, czavala@amauta.rcp.net.pe, rproano@uni.edu.pe, lmlavado@hotmail.com, solo2click@hotmail.com

Abstract: Under the Peru - Japan SATREPS Project a building monitoring network has been implemented in Lima city,under the support of JST and JICA. The network considering a set of 5 sensors installed on different levels of threebuilding: One is framed concrete structure, the second is a masonry and concrete wall building and the third is a hospitalwith concrete framed structure. The buildings are located in two kinds of soil of Lima (two in medium soil, and one inrigid soil). Since the installation of the sensors, seven moderate quakes has been register. This paper presents themonitoring response of one building and the dynamic characteristics measure from the stronger event registered for thebuildings. Good agreement with simulation previously performed was found, and the results give us the confidence forthe developed of parameters for the stiffness degradation under small and moderate quakes for concrete framed structures.

1. INTRODUCTION

buildings at UNI campus.

Under the Peru - Japan SATREPS Project, with thesupport of JST and JICA, a building monitoring network has
been implemented in Lima city since 2011.
A total of 15 sensors are to be installed on different
levels of three buildings: One is a framed concrete structure,
the second is a masonry and concrete wall building and thethird is a hospital with concrete framed structure. One of therecorded moderate quake is shown and the response of abuilding analyzed and compared with previous studies.
1.1 Sensors Network Setting
Accelerations sensors are connected through internal
network and IP addresses to access to Internet

Figure 1 Connection of sensors to network through IP
address and internet
After preliminar testing period in a local network(Figure 2), a set of 5 sensors has already been set in 2

Figure 2 Network setting test and final placement ofsensor at basement level in UNI Central Building
At each building, the 5 sensors set are aligned to avertical line, and if possible near to gravity center. At thebasement level, sensors has been fixed in a hole box in floor,
and then at ceiling (slab) for each upper level.
1.2 Selected Buildings
The criteria for the selection of the buildings to bemeasured was the consideration of likely used structural
system in Peru and also the different combination ofmaterials.
A set of 5 sensors will be installed in each of threebuildings, which was selected as representative of typicalstructures and material: Central Building of UNI is 3F+ BF Level and 16m high,irregular configuration in plan, with masonry and- 1691 -

concrete walls and concrete frame structure built morethan 80 years ago, used mainly for administrative
offices
G2 Block at Civil Faculty of UNI, is for classrooms, a3F framed RC building with irregular configuration ofstiffness due to its distribution of masonry walls (hall at1F, corridors and classroom at upper floors).
Block A of Edgardo Rebagliati Martins National
Hospital is a 14F+BF building, more than 50 years old,
RC framed building, classified as essential type for its
importance of use.

2.2 Central block of G2 building at Civil Engineering
Faculty of UNI
Central Block G2 Bldg of Civil Engineering Faculty(FIC) is a 58 year old, reinforced concrete framed, 3-stories(10m high) structure with one underground floor. Half of its
typical plan continue down to a basement floor. First floor isthe main entrance hall, and upper levels are for classroom
and corridors. So, in plan shown regular configuration (28mx 12m approximately), but some masonry thick walls(250mm) not aligned, in upper levels, changes its stiffness ateach story (soft floor).

Figure 3 Central Building and G2 bldg block (North view)at Civil Engineering Faculty at UNI
2. PRELIMINAR STUDIES OF SELECTED
BUILDINGS FOR MONITORING
2.1 Central Administrative Building of UNI
As shown in figure 4, plan of Central Building of UNI isirregular its longer dimension L=117m and B=23m wide forthe main body. Sensors has been set to the South-East part ofthe building about 0.25L from gravity center

Figure 6 Location of Central Block G2 in FIC and Southside view of building
Previous studies and evaluation has shown somereference values for natural period of building: Frommicrotremor measurement (2007) Tx (longitudinaldirection): 0.195s, and Ty (short direction): 1.62s
Preliminary analysis confirms a weak first level withgreater relative displacements. Observing damage andfailure at columns before than beams. From theoreticalelastic analysis, it was obtained periods of 0.31s for firstmode, which model is shown in figure 7

Figure 7 Modeling G2 building and deformed configuration
Figure 4 Plan of Central Building in UNI and location ofsensors
Some previous calculation and measurement has been
conducted as reference for assess dynamic monitoringresults. Microtremor measurements has been conducted in 3
points (soil: center zone and at 3F: NO and SE wing ofbuilding) and showed fundamental periods (from Fourier
Amplitude Spectra) of Tx=0.23s and Ty=0.28s for thebuilding where X is longitudinal axis, and for soil Ts= 0.41s.

Setting of sensors was located at center of gravity inplan, aligned in a vertical line, and is shown in figure 8

Figure 5 Preliminary measurement and analysis:
microtremor and modeling

Figures 8 Central Block in G2 FIC and setting of sensors
to the ceiling (below)- 1692 -2.3 Edgardo. Rebagliati Martins Hospital - Building A(East block)This 14F, reinforced concrete building, 55year old,beard 2 main earthquakes (1966 and 1974), but main
structure have not been damaged. “A-Block” was focusedfor this study and is the right block show in Figure 9.
Dimensions in plan are 15.9m x 73m, and 45.6m high fromground level with 14F
Figure 10 Notice of registered event at ITK network for
UNI building
Additional data of this event to process: Depth 53Km,
Latitude -11.42ºS; Longitude -77.92º
Data for G2-FIC building has been processed. Figures
11 and 12 show signal at basement and 4F. It is possible toread that acceleration on the top of the building reach a valueof 20 gal, almost 3.3 times the basement acceleration.

Figure 9 E Rebagliati Hospital and studied block

Figure 11 Response recorded at basement level

As reference also for this building exist two previous
studies: evaluation 1997 and more detailed, non linear
analysis conducted for a thesis research. For intermediatelevel earthquake, predicted damage are expected in beams inboth directions of analysis, endangering inmediatly
occupancy or interrupting normal performing of functions as
hospital
3. DATA ADQUISITION FROM RECENT EVENTSAND RESULTS
Since the installation of the sensors, seven moderatequakes has been registered in the network. In table 1 isshown a official List of Earthquake registered by IGP
National Network in November and December 2012.
Lightened row of table 1, was registered as 2.6 max responseat upper level in the network notice, as shown in Figure 10.
Table 1 List of Earthquake registered, Nov&Dec 2012
Lima studied
List of Earthquakes registered, Novblock& Dec 2012 (Lima)
DateTime

Magnitude

1

03/11/2012

20:52:12

4.7 ML

III-IV Yauyos; III Lima2

13/11/2012

00:48:58

4.0 MLII Lima3

15/11/2012

19:21:55

4.8 MLIII San Vicente de Cañete, Chincha
Alta; II-III Lunahuana; II Lima, Ica

427/11/2012

04:19:59

4.4 MLIII Barranca; III II Huacho; II Lima

522/12/2012

01:43:39

4.2 MLII Chila, Lima

628/12/2012

20:57:40

4.3 ML

II-III Huaral, Lima

731/12/2012

03:46:17

4.7 ML

III-IV Huacho III Lima

Figure 12 Response recorded at 4F level
Response of each level has been processed. Figure 13
shows predominant modal distribution and a large
displacement evidence very flexible N-S direction comparedwith E-W.

Intensidad - localidadesFigure 13 Predominant modal distribution- 1693 -Table 2 shows predominant period for each direction ofanalysis. Values of periods for mode 2 in this table agreewith previous measurements (see item 2.2)

city. Two on buildings at UNI campus and other set at
Edgardo Rebagliatti Hospital. The instalation process has
been presented and the sensors are now on line.

Table 2 Predominant periods (s) for each direction

Monitoring response of one of selected buildings andthe dynamic characteristics measure from the events has
been presented. Good agreement with simulation previously
performed was found, and the results give us the confidence
for the developed of parameters for the stiffness degradation
under small and moderate quakes for concrete framedstructures.

mode
123EW
0.22
0.19
0.15

NS
0.23
0.16
0.12

Figures 14 and 15 shows spectra (acceleration andvelocity) for basement level measurements

Acknowledgements:
The authors would like to express our gratitude to the Ministryof Education of Japan, thorough the Japan Science and Technology
Agency (JST) and the Japan International cooperation Agency(JICA) for the support the Japan-Peru SATREPS Project for thesupport to this research. Also our gratitude to Dr. Fumio Yamazaki
PI investigator of the SATREPS project and promoter of thisinvestigation.
Also our gratitude to Msc. Miguel Diaz graduate student of theFaculty of Engineering of Yokohama National University for thesupport in the elaboration of this paper and or his great
contributions during the data processing
References:Zavala T, Carlos, Reyna, Roy. (2011) Preliminary Report“Medición de vibración ambiental en la estructura del Pabellón
Central UNI” for Satreps- JST-JICA Project
Moya L, Zavala C., (2012) Preliminary Report “EvaluaciónEstructural del Pabellón G2 de la Facultad de Ingeniería Civil”
for Satreps- JST-JICA Project
Camacho V, Audry (2010), “Vulnerabilidad Sísmica Estructural delos Edificios Principales de la Facultad de Ingeniería Civil de laUniversidad Nacional de Ingeniería”, Undergraduated Thesis for
Civil Engineering, FIC-UNI, Lima, Peru
Fajardo G, Cesar (2012) “Evaluación estructural de una de las
edificaciones del Hospital Edgardo Rebagliati M”
Undergraduated Thesis for Civil Engineering, FIC-UNI, Lima,Peru

Figure 14 Acceleration spectra (h=0.05). signal frombasementFigure 15 Velocity spectra (h=0.05). signal from basement
Both figures presents peaks values at the predominantperiods and components of acceleration reach a maximum
spectral component for a range between 22 to 27 gals foreach direction of the building. Also the velocity indicates apeak value between 0.3 s. to 0.38 s. for this building.
4. CONCLUSIONSFirst building monitoring network has been installed
and is working at the present time in Lima Peru, as an outputof the Project for Enhancement of Earthquake and Tsunami
Disaster Mitigation Technology in Peru (JICA/JST), under
the cooperation scheme of SATREPS.
Three sets of five sensors have been installed in Lima

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