IISEE Newsletter Special Edition
November 2020

Foreword
Our institution, International Institute of Seismology and Earthquake Engineering (IISEE), mainly conducts threefollowing one-year training courses named (S) Seismology Course, (E) Earthquake Engineering Course and(T) Tsunami Disaster Mitigation Course.
This booklet is a collection of abstracts of individual study reports from the trainees of the 2019-2020 course.
Regarding the trainees from S course and T course, only trainees who have volunteered wrote their abstracts.
Therefore, please kindly note that not all the abstracts are posted in this booklet.
Their further detailed synopsis can be found on the following website.
https://iisee.kenken.go.jp/syndb/
Also, you can watch the final presentation from five trainees on IISEE E-learning website.
https://iisee.kenken.go.jp/el/
We hope this booklet will help you.
Tatsuya Azuhata
Tatsuhiko Hara
Bunichiro Shibazaki(E Course leader)(S Course leader)(T Course leader)International Institute of Seismology and Earthquake Engineering,
Building Research Institute1 Tatehara, Tsukuba, Ibaraki 305-0802, JAPAN.
E-mail: iisee@kenken.go.jp

Table of Contents
Seismology Course
2.
3.
4.

Estimation of Surface Wave Dispersion Characteristics Using Ambient Noise
Records in Ulaanbaatar Region
Strong Motion Estimation in Costa Rica at Specific Sites Using Spectral Inversion
MethodStrong Ground Motion Simulation of the 2019 Java, Indonesia, Earthquake (Mw
6.9) Using Empirical Green’s Function Method

Engineering Course
5.

Detail Seismic Performance Evaluation of a Twelve (12) Storied Official Building in
Dhaka and Suitable Retrofitting Technique
6. Seismic Evaluation and Retrofitting of Traditional Bhutanese Residential House
7. Proposal of Ground Motion Prediction Equation (GMPE) for Chilean Ground
Motion Records and Its Application
8. Evaluation and Retrofitting of a Historic Adobe Masonry Building
9. Seismic Evaluation and Retrofitting of Existing Reinforced Concrete Buildings in
Myanmar
10. Seismic Performance Evaluation for Continuous Use of an Existing Bridge in
Nepal
11. Earthquake Performance Evaluation of Typical Bridge Structures with Seismic
Isolation and Soil Structure Interaction in the Philippines

Tsunami Course
12. Tsunami Modeling of the Anak Krakatau Volcano for Development of Tsunami
Warning System in the Sunda Strait

1

Estimation of Surface Wave Dispersion Characteristics
Using Ambient Noise Records in Ulaanbaatar Region
1.6cm

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Lkhagvadorj DALAIJARGAL
Institute of Astronomy and Geophysics, Mongolian Academy of Science (IAG), Ulaanbaatar,
Mongolia
E-mail : mnlhagvaa@gmail.com

Takumi HAYASHIDA (Supervisor)
International Institute of Seismology and Earthquake Engineering, Building Research Institute,
JAPAN

Seismic interferometry is a technique for extracting Green’s function from ambient noise cross-correlations
between two receivers is now an effective tool to illuminate subsurface structures such as crust and uppermost
mantle of the Earth from the regional to global scale. Our study obtained Rayleigh and Love wave dispersion
characteristics between 5 s and 20 s from yearly-stacked cross-correlation functions (CCFs) of ambient seismic
noise data (between January 1, 2018 and January 1, 2019), using the dense seismic broadband network
consisting of 17 stations in the Ulaanbaatar region, Mongolia. The extracted empirical Green's functions ofRayleigh and Love waves between 136 pairs of stations showed substantially large signal-to-noise ratios (> 17) inthe target periodic range, indicating clear trends of wave propagation up to ~270 km. We used transversetransverse (TT) component for the estimation of Love wave dispersions. As for Rayleigh wave. we removed Pwave contamination, which exists as precursors, from the stacked CCFs using vertical-to-radial (ZR) and radialto-vertical (RZ) components and succeeded in obtaining dominant Rayleigh-wave signals. The estimatedRayleigh and Love-wave phase velocities using the matched-filter frequency-time analysis (Fig. 1) showed little
variation over the period between 6 s and 10 s, indicating small subsurface heterogeneity in the Ulaanbaatar
region. The estimated Rayleigh wave phase velocity map for 8 s indicated small (~0.05–0.1 km/s) velocity
contrasts between the western and eastern parts, suggesting the possibility of local-scale seismic velocity
heterogeneity in the study area. The resulting velocity trend corresponds well with the estimations derived with asparse seismic array. We also found a significant feature which could extend our Rayleigh wave phase velocity
dispersion to a much longer period, and shorter spacing stations, (which are typically excluded in seismic
interferometry) could be included using the spatial autocorrelation (SPAC) method (Fig. 2). The combined use of
the two methods makes it possible to conduct a tomographic study in the Ulaanbaatar region.

FigureFig. 1. Measured Rayleigh and Love wave phase and groupvelocities for all station pairs, (a) Rayleigh wave, (b) Love wave.

Fig. 2. The comparison between
the SPAC results and seismic
interferometry results .

Institute of Astronomy and Geophysics of Mongolian Academy of Science
The Institute of Astronomy and Geophysics (IAG) of the Mongolian
Academy of Science (MAS) was established in 1957. The IAG is the only
organization that conducts geomagnetic and seismological studies under
the government budget. It also closely collaborates with the National
Emergency Management Agency and National Security Council with its
main duty that provides emergency information about earthquake
occurrence.

2

Strong Motion Estimation in Costa Rica at Specific Sites Using
Spectral Inversion Method
1.6cm

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Photo

Nathalie Yoliana CHAVARRÍA ESQUIVEL
Costa Rican Electricity Institute, COSTA RICA
E-mail : natyoli90@gmail.com

Toshiaki YOKOI (Supervisor)
International Institute of Seismology and Earthquake Engineering, Building Research Institute,
JAPAN

Determination of site effect at different stations as a way to secure lifeline
facilities
The complex tectonic setting of Costa Rica implies the necessity of a real seismic hazard scenario
characterization for lifeline facilities and the country. In this paper, one of the conventional spectral inversion
techniques is applied to strong ground motion records obtained at important facilities including powerhouses
distributed over the country, with the purpose of separate the site effect, the source spectra, and the path effect.
To assure the quality of the results, the broadband station JTS of IRIS/IDA is also incorporated. A first consistency
check was established to assure the appropriateness of the input data using the individual site effects. Onceinversion was performed using the reference events and a depurated database, the frequency-dependent quality
factor 𝑄 = 179𝑓 0.5598 was obtained for the northern and central part of Costa Rica, along with the source spectra
and the individual site effect (Fig. 1). A second consistency check was performed to assure the results usingsynthetic acceleration spectra in comparison with the real observed ones.
Based on the results of the inversion, synthetic acceleration amplitude spectra for the 2012 Sámara earthquake of
Mw 7.6 at specific sites were calculated and could be consistent with the intensity anomaly observed during thisearthquake (Fig. 2). This method of reproduction may allow us to estimate acceleration spectra of major
earthquakes, and to develop a proper seismic hazard analysis of the country. Recommendations are given basedon the lessons obtained during the analysis to better and reinforce the strong motion observation of the Costa
Rican Electricity Institute (ICE).

FigureFig. 1. Site effect of the strong motion stations,normalized by PPA8 (rock site station).

Fig. 2. (left) Anomalous intensity distribution (modified from
RSN, 2012) and (right) synthetic spectra at Poás station forthe 7.6 Mw 2012 Sámara earthquake .

Costa Rican Electricity Institute

The Costa Rican Electricity Institute (ICE) is a public institution created in1949 to provide electricity to the entire country. ICE uses hydroelectric,
geothermal, wind, and solar sources to produce energy. Today, ICE
provides electricity to 99% of Costa Rica’s territory, obtained from 100%
renewable energy most days of the year. To secure the inversion given
by ICE, in 1973 the Seismology and Volcanic Auscultation and threats
department was created, and from 1975 became a member of the
National Seismological Network of Costa Rica (RSN UCR-ICE).

3Strong Ground Motion Simulation of
the 2019 Java, Indonesia, Earthquake (Mw 6.9)
Using Empirical Green’s Function Method
Ardian Yudhi Octantyo
Agency for Meteorology, Climatology and Geophysics, REPUBLIC OF INDONESIA
E-mail : yudhi.octantyo@gmail.com

Hiroe MIYAKE (Supervisor)
Earthquake Research Institute, University of Tokyo, JAPANToshiaki YOKOI (Supervisor)
International Institute of Seismology and Earthquake Engineering, Building Research Institute, JAPANThrough the adjustment of the scaling parameters, adequate synthetizedwaveform of the large intraslab earthquake can be achieved using plateboundary earthquake records
This study estimated strong motion generation area parameters and simulated the strong ground motion of the 2August 2019 (Mw 6.9) intraslab earthquake and a hypothetical plate boundary earthquake (Mw 8.7) using thestrong motion records of the 11 August 2019 (Mw 5.1) plate boundary earthquake with the empirical Green’s
function method. We first estimated the strong motion generation area that reproduced the strong ground motion
during the Mw 6.9 intraslab earthquake and conducted a rough estimation of the scaling parameters to see theimpact of these parameters on the performance of the synthetic waveform reproduction. We also adjusted thestress drop ratio parameter (C) for some station records, which is sensitive to waveform amplitude. Adequate
synthetized waveform for the estimated strong motion generation area can be achieved for acceleration, velocity,and displacement pulses (Fig. 1).
We then modeled the strong motion generation area of the Mw 8.7 hypothetical plate boundary earthquake using
the Mw 5.1 plate boundary earthquake and the Mw 6.9 intraslab earthquake as the element events (Fig. 2). The
estimated peak ground acceleration values from the empirical Green’s function simulation were compared withthe conventional ground motion prediction equation. The comparison provided a simulated acceleration level
excited by a hypothetical Mw 8.7 that may occur in the future. The variability of simulated ground motion in termsof methods, source type as the element event, and rupture directivity effect was confirmed.

FiguresFig. 1. Ground motion simulation results of theMw 6.9 intraslab earthquake using the Mw 5.1
plate boundary earthquake at CLJO station(EW component).

Fig. 2. Strong motion generation area estimated tosimulate the Mw 8.7 hypothetical plate boundary
earthquake using the Mw 5.1 plate boundary
earthquake and the Mw 6.9 intraslab earthquake as
the element events.

Agency for Meteorology, Climatology and Geophysics (BMKG)The Agency for Meteorology, Climatology and Geophysics is a government
institution that carries out government tasks in the fields of Meteorology,
Climatology, Air Quality and Geophysics in accordance with the provisions of theapplicable laws.

4

Detail Seismic Performance Evaluation of a Twelve (12) Storied
Official Building in Dhaka and Suitable Retrofitting Technique
Rajib Kanti BISWASAssistant Engineer, Public Works Department, BANGLADESH
E-mail : rajib_kanti_biswas@yahoo.com

Matsutaro SEKI* and Yosuke NAKAJIMA** (Supervisor)*Visiting Research Fellow, International Institute of Seismology and Earthquake Engineering, Building
Research Institute, JAPAN**Principal Engineer, Engineering and Risk Service (ERS), JAPANThe detail seismic evaluation is a more rational and practical one toevaluate the seismic performance of the building.
The main purpose of this study is the evaluation of the seismic performance of the existing RC building situated in
Dhaka and constructed before the establishment of the National building code, 1993. Currently, Bangladesh
National Building Code (BNBC) is being updated. Significance changes in seismic provisions have been brought.
Therefore, it is necessary to evaluate seismic performance and the strengthening of old buildings to keepcompatibility with the requirement of updated building code. This study compares the seismic evaluation results ofbuilding by the 2nd level screening method of Japan Building Disaster Prevention Association (JBDPA), 2001, anddetail seismic evaluation method and suggests a suitable retrofit technique. The JBDPA, 2001 standard mainly
targets weak-column and applies for low to mid-rise buildings. Therefore, it provides inaccurate results for weakbeam building. On the other hand, the concept of detail seismic evaluation method is based on both the Japaneseand the American seismic evaluation method. This method can evaluate the actual behaviors of weak-beambuildings during earthquake events. To evaluate the seismic performance of the building by detail seismic
evaluation method, non-linear static pushover analysis was performed according to ATC 40, 1996 / FEMA 273,
1997 /356, 2000 /440, 2005 and ASCE 41, 2013. The damage distribution and sequence of the collapse of thebuilding were observed. It was found that detail seismic evaluation method provided most rational and practicalresults rather than 2nd level screening method of JBDPA, 2001 from the viewpoint of seismic evaluation of thebuilding due to the target building was found to be weak-beam and high-rise building. Furthermore, the required
strength for retrofit was easily estimated by this method. The new shear wall for retrofit proved to be effective inincreasing the necessary seismic capacity of the building.

FigureAfter Retrofit

Spectral Acceleration,
Sa

RC

R∆C

CC

0.1

Before Retrofit
F

RF(X-Direction)
IS0 = 0.213 > IS = 0.127
Judgement: Unsafe
CPIS = 0.0385 ✕ 3.308 = 0.127

0.2

CPC = 0.0385

Initial Stiffness

YPCP

CPF = 254.7/76.99 = 3.308

0.0

F

0

Fig. 1. The calculation procedure of required strength
for retrofit. RIS0 is Newly defined based on structural
type after retrofit. RF, new ductility index is consideredwhich will be less than the existing F value.

200
400
Spectral displacement, Sd

Fig. 2. Evaluation by detail seismic evaluation (Xdirection). The seismic index of the structure is foundto be 0.127, which is less than seismic demand(0.213). Therefore, it is judged that this building does
not have the adequate seismic capacity.

Public Works Department (PWD), Bangladesh
Public Works Department (PWD), under the Ministry of Housing andPublic Works, is the pioneer government organization for designing,
construction & regulating buildings in Bangladesh. Over about two
centuries, PWD could successfully keep up the country's infrastructuredevelopment trend and standard. Currently, PWD involves various
projects related to earthquake disaster management, especially in retrofit
buildings.

5

Seismic Evaluation and Retrofitting of Traditional
Bhutanese Residential HousePEMA
Division for Conservation of Heritage Sites, Department of Culture, Ministry of Home and Cultural
Affairs, BHUTAN
E-mail : pema0789@gmail.com

Takayoshi AOKI (Supervisor)
Nagoya City University, JAPANThe first of its kind conventional fragility curves are developed based on
capacity curves derived experimentally for traditional Bhutanese houses.
Traditional stone masonry houses form an integral part of the unique landscape of Bhutan. Unfortunately, thesestructures are highly vulnerable to seismic activities, but only limited research works for the vernacular masonry
constructions. Thus, this paper explicitly deals with the development of seismic technology to strengthen suchrandom rubble masonry structures in mud and cement mortars. This study’s basis is the full-scale quasi-static test
conducted on two-storied residential houses designed based on a representative sampling of traditional houses
for unreinforced and retrofitted types. The proposed seismic intervention is the mesh-wrap retrofitting technique.
There are three components in this research study: (i) Three phases of seismic evaluation of random rubble
masonry, i.e., specification code, allowable unit stress calculation, and horizontal load-carrying capacity; (ii)Experimental campaigns and FE-based numerical simulations and (iii) Seismic fragility assessment with
development of experimental based fragility curves based on capacity spectrum method. Firstly, the seismic
evaluation helps in easy assessment and judgment of the seismic capacity, employing simple hand calculations
without using a sophisticated analysis tool. Secondly, the full-scale quasi-static test reveals that the proposed
mesh-wrap retrofitting technique effectively increases the seismic capacity of such structures, i.e., 1.58 times thebase shear of conventional (unreinforced) structures. We developed a Finite Element based numerical models
and conducted non-linear pushover analyses. The FE-numerical model was capable of simulating the structural
response similar to the experimental campaign. Thirdly, the developed fragility curves are first of its kind for stone
masonry houses of Bhutan, with a clear definition of limits states.

FiguresFig. 1. Schematic full-scale quasi-static test setup (left) andExperimental capacity curves in terms of base shear (kN) and top
storey drift (%) for Unreinforced rubble Stone Masonry in Cement
mortar (USMC),Retrofitted rubble Stone Masonry in Cement
mortar (RSMC) and Retrofitted rubble Stone Masonry in Mudmortar (RSMM) in blue, red and black lines respectively (right).

Fig. 2. Fragility curve of USMC house. Eachdotted lines corresponds to limit states:
Immediate Occupancy (IO), Life Safety (LS)and Collapse prevention (CP). Similar curves
are also developed for RSMC and RSMM
structures.

Department of Culture, Ministry of Home and Cultural Affairs
The Department of Culture is a government entity responsible for thesustenance of cultural heritage and Bhutan's cultural landscape for thepresent and future generations, amongst other mandates. It places
importance on integrating cultural heritage into all areas of national
development. “A nation stays alive when its culture stays alive”. Pleaserefer to http://www.departmentofculture.gov.bt for more details.

6Proposal of Ground Motion Prediction Equation (GMPE) for
Chilean Ground Motion Records and Its Application
Victor Pablo DIAZ GOMEZ
Ministry of Publics Works, Structural Projects Department, Chile
E-mail : vpd.ingenieria@gmail.com

Shojiro KATAOKA (Supervisor)
National Institute for Land and Infrastructure Management, JAPANA Japanese Ground Motion Prediction Equation modified by Chilean
records, has a correct correlation with Chilean Earthquakes.
After the 2010 Chilean Earthquake, buildings design code was upgraded in topics related to spectrum design and soil
classification. However, the bridge's design code keeps the same spectrum design and the same soil classification. Therefore,
it is necessary to analyze it. The main target of this research is to propose a Ground Motion Prediction Equation (GMPE), topredict seismic intensity in different locations in Chile, and analyze current spectrum design for bridges. Due to a short timeof research, I use an existing GMPE given by Dr. KATAOKA Shojiro from NILIM. This equation was developed in Japan;
therefore, it is based on Japanese soil classification and its natural period. The current soil classification in Chile inside thebridges’ code, is not depending on the natural period of the soil. Therefore, it is necessary to create a database with thismodification or correlation to be able to use this GMPE in Chile. The essential information will be obtained from thenational seismic network supervised by the University of Chile. The activities in this research are: (a) Create a database witha natural period of soil for each seismic station in Chile. For this, I will obtain acceleration records from the seismic stationin Chile. In addition, I will get all the input information to use GMPE (the type of soil, the depth of hypocenter, and theshortest distance from the seismic station to the rupture area). (b) Find the modification factor for the equation using thegeometric mean value of the spectrum ratio (acceleration spectrum over the predicted acceleration spectrum). The geometricmean value must trend to 1. (c) Validate GMPE Modified with Chilean accelerometers records for earthquakes with seismic
intensity between 5.0 Mw and 8.8 Mw. (d) Use this modified equation in some study cases, and (e) Analyze the current
spectrum design of the Road Manual in Chile. The results show that the GMPE Modified geometric mean value trend to one
and develop a correct correlation with Chilean Acceleration Records.

FigureFigureFigureFig. 1. GMPE Modified curve for soil type I and
depth equal to 21 km magnitude 6 Mw, 7 Mw,
8 Mw and 9 Mw. Dots are Chilean acceleration
records in Mw.

Fig. 2. GMPE Modified Acceleration Response
Spectrum comparing with Road Manual (MC). X is the
hypocenter distance. The current spectrum design
must be upgrade and increase the acceleration peak.

Ministry of Publics Works
The Ministry of Public Works (MOP) is the cabinet-level administrative
office in charge of planning, studying, designing and constructing as well
as repairing, maintaining and operating public infrastructure in Chile.
Its work embraces roads, highways, bridges, tunnels, airports andairfields. It is also responsible for the management, distribution, use andconservation of all water resources within the country.

7

Evaluation and Retrofitting of a Historic
Adobe Masonry Building
1.6cm

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William Alexander RAMOS HERNANDEZ
Department of Built Cultural Heritage, Ministry of Culture, EL SALVADOR
E-mail : willalexra@hotmail.com

Shunsuke SUGANO (Supervisor)
Professor Emeritus, Hiroshima University, and Visiting Research Fellow, International Institute of
Seismology and Earthquake Engineering, Building Research Institute, JAPAN

Overlay walls, a technique widely used in Japan to retrofit RC structures,
can improve the seismic capacity of a real Adobe Masonry Building.
Most old buildings in El Salvador are made out of adobe, a type of earth masonry that is built using
traditional techniques. Their architectural beauty and their ancient origins are why they are considered Cultural
Heritage. But there is a problem: They are extremely weak against earthquakes. After several devastating
earthquakes, people understood the importance of seismic retrofitting. However, adobe is a non-engineeredmaterial, and thus, there are too few studies of its seismic behavior and almost no studies regarding its retrofitting.
This study was conducted to find the best retrofitting solution for adobe buildings. A 150-years-old historic adobebuilding was evaluated, and three retrofitting alternatives were selected: Polypropylene band wrapping,
Reinforced Concrete (RC) wall affixing, and RC frame affixing. Three analysis methods were used to determine
the seismic performance of each alternative: Seismic Index (Is), capacity spectrum method, and response history
analysis. Finally, two levels of seismic demand were used: A high level, taken from the Salvadorian Seismic Code,and a lower level, taken from a Probabilistic Seismic Hazard Analysis. Each retrofitting alternative was compared,by their seismic performance, the amount of material needed, and their impact on the historic value of the building.
The Polypropylene band wrapping solution was not enough for a building which was very fragile and located at asite with high seismicity. The RC frame affixing solution worked, but it requires partial demolition works andcauses extensive cracking on the walls. Finally, the Backside wall affixing technique provided the right balance
between its impact on the historic value of the building and seismic performance, while presenting a failure modethat protects the walls from damage. Therefore, this is the best solution to retrofit the target building.

FigureFig. 2. Capacity curves of all the retrofitting
techniques and the original building in the N-S
direction. The high demand spectrum and the demandline are shown.

Fig. 1. Flowchart with the evaluation process for eachretrofitting solution.

Ministry of Culture, El Salvador
The Ministry of Culture (MICULTURA), established in 1991, is theinstitution that guarantees the conservation, promotion and disseminationof culture in El Salvador. It is the only institution in the national
government in charge of the conservation of Historic Buildings, throughits Department of Built Heritage (DPCE).

Example8Seismic Evaluation and Retrofitting of Existing Reinforced
Concrete Buildings in Myanmar
Nwet Nwet Yi
Ministry of Transport and Communications, Department of Meteorology and Hydrology, Myanmar
E-mail : nwetnwetyi90@gmail.com
Tatsuya AZUHATA (Supervisor)
International Institute of Seismology and Earthquake Engineering, Building Research Institute,JAPAN

Installing RC Shear Walls and RC Column Jacketing are appropriate
retrofitting methods in Myanmar
Myanmar is an earthquake-prone country. In this study, hazard maps were initially used to implement anearthquake disaster mitigation strategy. Two cities, in particular, Mandalay and Yangon, were selected toinvestigate the hazard risk of buildings in the high and low seismic zones. A three-story reinforced concrete (RC)building with brick walls was evaluated by the Japan Building Disaster Prevention Association (JBDPA) standard
and the Capacity Spectrum Method (CSM). The Standard Japanese guide has three seismic screening levels: thefirst, second, and third. These three levels were used for the seismic evaluation and verification of seismic
retrofitting of existing low-rise and medium-rise RC buildings. The CSM is used to analyze the maximum responseof a structure under an earthquake ground motion. In this study, the first and second screening levels were used
to check the building's seismic capacity. The building was analyzed again by the CSM using the STERA 3D
program. After evaluating the target building with the JBDPA standard and the CSM, the target building did notmeet requirements. Two simple retrofitting methods, RC column jacketing and RC shear wall, were applied inorder to retrofit the target building. After construction of a small number of RC shear walls and increasing the sizeof selected columns on the 1st story, the building could be designated safe, even in a very high seismic zone. The
results showed that we could obtain satisfactory earthquake-resistant buildings. Therefore, the Japanese seismic
evaluation and retrofitting methods can be adopted in Myanmar to evaluate and upgrade the seismic performanceof the existing RC building.

Figure4

Before retrofit (Second Level Screening)

Story

3
2
Iso

1

Is (X-direction)
Is (Y-direction)

0
0

4

0.2

0.4

0.6

Is and Iso

0.8

1

1.2

1

1.2

After retrofit (Second Level Screening)

Story

3
2

Iso

1

Is (X-direction)

Is (Y-direction)

00

Fig.1. Front elevation and the first floor’s plan of thetarget building. The blue lines in the plan show
shear walls for retrofit.

0.2

0.4

0.6

Is and Iso

0.8

Fig.2. Comparison of Is (capacity) with Iso (demand)
before and after retrofit

Department of Meteorology and Hydrology (DMH)
The Department of Meteorology and Hydrology (DMH) is under the
Ministry of Transport and Communications. The DMH aims to takeprecautionary measures against and diminish the effect of natural
disasters, to promote safety, comfort, and efficiency of air, land, sea, andwater transportations, to promote agriculture and food production, toensure efficient operation, development of activities in defense, health,social welfare and all sectors of the national economy, and to bringsustainable development of natural resources.

9

Seismic Performance Evaluation for Continuous Useof an Existing Bridge in Nepal
1.6cm

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Amit Kumar VARMA
Highway Engineer, Road Division, Palpa, Department of Roads, Kathmandu, Nepal
E-mail : akv.osm@gmail.com

Tatsuya AZUHATA (Supervisor)
International Institute of Seismology and Earthquake Engineering, Building Research Institute,JAPAN

For the continuous use of an existing bridge designed under the old IRC
codes, the structure should be retrofitted with steel jacketing.
Road network is still the primary transportation system in Nepal, and bridges are the most sensitive part of thatsystem. Most of the bridges were constructed about 40-50 years ago based on the design life of 50 years andtraffic forecast for 30 years. The design was based on an allowable stress method as per Indian Road Congress(IRC) guidelines. In those codes, a small value of seismic design force was considered, and also there was noprovision for shear design of a compression member. The effective design life of these structures is coming to an
end. After the 2015 earthquake, there is an earnest need for seismic evaluation to propose some retrofitting
techniques for the continuous use of existing bridge structures in Nepal.
The structure was evaluated separately for the allowable stress method and ultimate capacity method as per therevised code. The seismic performance of the bridge was then estimated with the Capacity Spectrum Method andthe Response History Analysis. These analyses imply that the structure has enough capacity to meet the seismic
demand as per the revised code or when the double lane standard deck replaces the existing one. Though thepier had a high capacity, the pounding occurred in the longitudinal direction. As the abutment restricted the
movement, the damage is concentrated on the superstructure rather than the pier. The shear failure occurred in
the transverse direction, which is not accepted for safety purposes. Therefore, the structure should be retrofitted
to increase its shear capacity. For this purpose, steel jacketing was proposed for the continuous use of an existing
structure as it is a very suitable method for developing countries such as Nepal.

FigureFigureFigureFig. 1. The target bridge structure with theexisting and newly proposed superstructure.

Fig. 2. Capacity curve versus demand spectrum forthe existing and new superstructure.

Road Division, Palpa, Department of Roads (DoR), Kathmandu, Nepal

ExampleRoad Division, Palpa is one of the divisional office under the DoR. The
main objective is to develop, expand, and strengthen the road network ina sustainable way for enhancing the overall socio-economic development.
The major responsibilities are planning, designing, procurement,
construction, maintenance and supervision of national highways andbridges.

10

Earthquake Performance Evaluation of Typical Bridge Structureswith Seismic Isolation and Soil Structure Interaction in thePhilippines
Joseph Christopher A. OROPEL
Department of Public Works and Highways, Bureau of Design, PHILIPPINES
E-mail : josephoropel@gmail.com

Tatsuya AZUHATA (Supervisor)
International Institute of Seismology and Earthquake Engineering, Building Research Institute,JAPAN

Lead rubber bearing (LRB) exclusively functioned towards rigid structureswith either fixed supports or pile foundations.
The current seismic code for bridges in the Philippines, Bridge Seismic Design Specifications (BSDS), adopts
concepts from the American Association of State Highway and Transportation Officials’ (AASHTO) Load andResistance Factor Design (LRFD) Bridge Design Specifications, 2012. It utilizes the Force-Based Design (FBD)
approach, which has been applied in bridge seismic design since the 1990 Luzon Earthquake. However, AASHTO
recently recommends the use of Displacement-Based Design (DBD) as an alternative approach in defining
seismic performance levels. This approach utilizes displacement as the main parameter to establish seismic
performance, predicting damage states more accurately. The study attempts to adopt the DBD method concept toinvestigate the effects of seismic isolation and soil-structure interaction (SSI) towards typical bridge structures in
the Philippines. The approach for evaluating the structure’s limit state and seismic performance was conductedfollowing the provisions of the Japan Road Association Specifications for Highway Bridges (JRASHB), 2012. The
application of isolation bearings on structures with distinctive natural periods was evaluated based on its effectivity
and applicability. The seismic isolation bearing, lead rubber bearing (LRB), exclusively functioned when applied torigid structures incorporating either fixed support or pile foundation conditions. Moreover, earthquake response
analysis was also performed to analyze its influence on the structure to develop a more accurate representation ofits seismic response. Furthermore, the effects of the individual and combined contribution from the parameters
were evaluated on its significance in affecting seismic performance.

Figures
141500 NB vs. LRB
Sa-Sd h =5%
Sa-Sd h =10.9%
1500 LRB
1500 NB

12

Sa (g)

108

Figure642
00Fig. 1. Multi degree of freedom system of thebridge considering soil-structure interaction
and seismic isolation.

0.2

0.4

0.6
Sd (m)

0.8

1

1.2

Fig. 2. Capacity Curve vs Demand Spectrum of the1500-F-NB and 1500-F-LRB models along thelongitudinal direction.

Department of Public Works and Highways
The Department of Public Works and Highways functions as the engineering andconstruction arm of the Government to continuously develop its technology for the
purpose of ensuring the safety of all infrastructure facilities and securing for all
public works at the highest efficiency and quality in construction. DPWH is currently
responsible for the planning, design, construction and maintenance of infrastructure,especially the national highways, flood control and water resources development
system, and other public works in accordance with national development objectives.

11

Tsunami Modeling of the Anak Krakatau Volcano for
Development of Tsunami Warning System in the Sunda Strait
1.6cm

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Photo

Arif NUROKHIM
Agency for Meteorology Climatology and Geophysics (BMKG), INDONESIA
E-mail : nur_arrohim@yahoo.co.id

Yushiro FUJII*, Hideaki YANAGISAWA** , Bunichiro SHIBAZAKI* (Supervisor)* International Institute of Seismology and Earthquake Engineering, Building Research Institute,JAPAN** Department of Regional Design, Faculty of Liberal Arts, Tohoku Gakuin University, JAPANSea level sensors evaluation is expected to provide important consideration fora development of the tsunami warning system for non-tectonic tsunami sources.
A tsunami caused by the Anak Krakatau volcano on 22 December 2018 resulted in significant casualties andproperty losses. Using the simplified landslide source models, we validated tsunami modellings by comparing theobserved tsunami waveforms at four tide gauges and measured tsunami heights from field surveys with thecalculated ones. We also conducted sensitivity tests changing the source parameters and tsunami simulation
settings. For the 2018 tsunami event, observed waveforms at tide gauges were almost reproduced in terms ofinitial wave arrival times and its amplitudes, although those at the tide gauges in Sumatra were not so well
reproduced in terms of the wave period. We calculated correlation indexes to quantitatively evaluate thesimulation results, and found that the calculated tsunami heights are almost half of the observed ones (Fig. 1).
In addition to the 2018 event, we assumed two future scenarios of landslide to the directions ofnorth and southeast from the geological activities of Anak Krakatau. Tsunami height simulations for the three
events were conducted to evaluate the potential tsunami hazard. Then, we identified that Labuhan and Carita
beaches in Banten, and the Kalianda beach area, southern Lampung have the most significant potential to be hit
by tsunamis with the heights of 2.5 - 6 m.
We also calculated the first-wave arrival time differences between the ocean bottom pressuregauge (OBPG) near Anak Krakatau and nine tide gauges at the coast along the Sunda Strait. The results showthat there are the leading times of 15 - 20 min for evacuation after the tsunami warning issued according to thedetection of the first wave at OBPG (Fig. 2). The evaluation of these sensors is expected to provide importantconsideration for a development of the tsunami warning system for non-tectonic tsunami sources.

FigureOBPG
Bakaheuni
Kota Agung
Panjang

Amplitude (m)2SebesiCiwandan
Merak

SerangLabuhan
Ujungkulon

1
0
-1 1

2

3

4 5678 910-20

5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80

Time (min)Fig. 1. Locations of sensors and comparison of
measured tsunami heights (red and blue circles) andcalculated ones (blue bars) for the 2018 tsunami.

Fig. 2. Tsunami waveforms calculated at OBPG and tidegauges for the 2018 event. The numbers in red show the
first arrival times of initial waves.

Indonesian Agency for Meteorology Climatology and Geophysics (BMKG)BMKG is a non-departmental government agency that carries out
government tasks in the fields of Meteorology, Climatology, Air Quality
and Geophysics in order to support public safety and the success ofnational development, and plays an active role at the international level.
Indonesia Tsunami Early Warning System at BMKG is tasked with
providing earthquake information and tsunami early warnings on anational scale, ASEAN and to countries around the Indian Ocean.

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