IISEE Newsletter Special Edition
December 2019

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 2018-2019 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.
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.

Completeness Magnitude of Earthquakes and b-Value in Myanmar

Engineering Course
3.
4.
5.
6.

Fragility evaluation of a RC building designed by Nepal Building Code considering
deformation capacity
Seismic retrofit of an existing residential building in Nepal to functionalize as a
hospital using ferrocement
A study on seismic performance and retrofit approach for current RC buildings
with soft first story in Nepal
Earthquake Performance Evaluation of Typical Bridge Structure Designed by aForce-Based Design Method in the Philippines

Tsunami Course
7.
8.

Study of the bathymetric influence on tsunami propagation near the coast of
Esmeraldas by tsunami simulation and ray tracing analysis
Evaluation of possible locations of bottom pressure recorder for the Colombiannorth Pacific coast, using tsunami travel times and tsunami simulations

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Completeness Magnitude of Earthquakes and bValue in Myanmar
Ngun Za Iang
Ministry of Transport and Communications, Department of Meteorology and Hydrology, Myanmar
E-mail : ngunzaiang@gmail.com

Saeko KITA (Supervisor)
International Institute of Seismology and Earthquake Engineering, Building Research Institute,
JAPANThe estimations of Mc and b-value are helpful to understand thecharacteristics of seismic activities and to evaluate the seismic
observation network.
In order to estimate completeness magnitude of earthquakes and b-values, the NEDC local dataset was usedduring 2014-2018. This study aims to estimate the completeness magnitude of earthquakes in Myanmar and to
examine the b-value with its relations: depth, faulting style, and stress accumulating in a sophisticated tectonic
setting of Myanmar. The completeness magnitude Mc was estimated as ML 2.8 with a b-value 0.68±0.02 in thewhole study region (Fig. 1). Regionally, the b-values vary from 0.52 to 1.0. The tendency relation between b-value
and faulting styles was found along the Sagaing Fault. The southern part with a smaller b-value indicates a thrustmechanism, whereas the northern part with a larger b-value shows a strike-slip mechanism. The b-value generally
increases with the increase of depth in the whole study region. In the active fault region, the b-value decreases
with depth within the upper crust at depths of ~15 km (Fig. 2), which might be related to high-stress accumulation.
Below at a depth of 15 km, the b-value then increases with a function of depth (Fig. 2). In contrast, a significant
decrease of b-value with depth was observed at depths of 75-85 km in the subduction zone of the study region,
which might be discussed with the process of dehydration in the ocean crust. The methodology of this study might
be fruitful to understand the seismically complex tectonic system beneath Myanmar.

FiguresFig. 1. Estimation of b-value and Mc in the wholestudy. Solid red line: the best-fit line. Circles: thecumulative number of events. Crosses: Event numberof each magnitude.

Fig. 2. Variation of b-values (yellow circles) with depth
and its error (red vertical bar) in the Sagaing Fault
region.

Department of Meteorology and Hydrology (DMH)
The Department of Meteorology and Hydrology (DMH) is under the Ministryof Transport and Communications. The DMH aims to take preventive
measures against and reduce the effect of natural disasters, to advance safe
transportations, to promote agriculture and food production, to ensure humansociety and national economy, and to bring sustainable development of
natural resources.

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Fragility evaluation of a RC building designed by Nepal
Building Code considering deformation capacity
2.8 cm

1.6cm

Your
Photo

Praveen Pratap ADHIKARI
Department of Urban Development and Building Construction (DUDBC), Kathmandu, NEPAL
E-mail : praveenadhikari76@gmail.com

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

Failure mode affects the fragility of buildings significantly
We carry out fragility evaluation of a reinforced concrete (RC) building to investigate the intensity of earthquakesthat the buildings designed by the current building codes in Nepal can resist. In this study, we select the RC
building shown in Fig. 1 with seven stories and five by three bays as a sample. For the preliminary process, we
carried out the non-linear static analyses to judge failure modes and estimate the ultimate limit story drifts. The
result showed that share failures might occur in this building. Therefore, we revised the arrangements andspecifications of steel bars both in columns and beams to prevent share failures with no changing dimensions ofthem. We also evaluate the fragility of this revised model comparing with that of the original one. To evaluate thefragility of the building, we conduct incremental dynamic analyses (IDA) using 40 earthquake ground motions. We
adjust the peak acceleration of them from 0.1 to 1.5 G in increments of 0.1 G. From the analysis results; weevaluate the relation of the probability of building collapse and the PGA, which is the fragility curve. For theoriginal building model, the probability of the collapse was 30 % to the PGA of 0.4 G. Contrary, that of the revised
model decreased to about 5%. The comparison of fragility evaluation of the models is depicted in Fig. 2. This
result shows that the failure mode affects the fragility of buildings significantly. The results of this study indicatethat RC frame structures designed by NBC can be achieved satisfactorily with some modification in the limit stateof shear design.

FiguresFig. 1. West elevations of the target building.

Fig. 2. Comparison of the fragility curves. Orange crosses
and green solid circles in the figure show the probabilityof collapse of the fragility curves for IDR 1/90 (shear
failure type) and 3/100 (bending failure type) respectively.

Department of Urban Development and Building Construction (DUDBC)The DUDBC organization falls under the Government of Nepal via the
Ministry of Urban Development. The functions and responsibilities of
DUDBC are: formulation, planning and implementation of urban policies;
formulation, planning and implementation of housing plans and policies;and design construction, repair and maintenance of the governmentbuildings.

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Seismic retrofit of an existing residential building in Nepal tofunctionalize as a hospital using ferrocement
Jyoti LAMSALStructural Engineer, Bharatpur Metropolitan City, Bharatpur Chitwan Nepal
E-mail : jyoti043lamsal@gmail.com

Koichi KUSUNOKI* and Matsutaro SEKI** (Supervisor)*Professor, Earthquake Research Institute, Univ. of Tokyo.
**Visiting Research Fellow, International Institute of Seismology and Earthquake Engineering, BRI.

Ferrocement is an appropriate retrofitting technology in developing
countries like Nepal.
Because of urbanization, the land price becomes high, and the space in the core cities of Nepal are not available
for constructing new facilities. Therefore, the trend of converting residential buildings to public buildings isincreasing. Here in this study, the existing non-engineered building that survived the 2015 Nepal Gorkha
earthquake that intended to shift its occupancy from residential to the hospital was evaluated. The building wasassessed considering the infilled and bare frame, and reevaluated the ferrocement retrofitted building using
JBDPA, 2001 and nonlinear pushover analysis. Three different techniques of the retrofit were considered (1partial retrofit, 2-whole wall retrofit, and 3-partial retrofit with some non-retrofitted additional walls). The structural
performance of the third types of retrofitting techniques was found to be best. To elaborate on the necessity ofretrofit for changing the functionality. Three different cases for the same target building were considered, using
nonlinear pushover analysis. Case: A as a residential building without retrofit, Case B as a hospital building
without retrofit (that depicts the current scenario of Nepal), and Case C as a hospital building with a retrofit. The
recent 2015 earthquake and NBC 105 demand curves are used for this study. Case A found to be safe in the2015 Gorkha earthquake and satisfied code provision, whereas case B could not satisfy any of the demand, andcase C satisfied both. The result of analysis could capture the real field scenario of Gorkha earthquakes. Manybuildings of case B types collapsed during the earthquake. However, Case C type building remain safer after theearthquake. The result of the case study implies that many existing non-engineered buildings by the recent
earthquake are in a vulnerable state and needs a retrofit. In the same way, this thesis identifies the retrofitting isurgent need before switching the occupancy of the buildings.

FiguresFigure 1. Capacity curve versus NBC &Gorkha earthquake 2015 demand curve forcase A, B and C

Figure 2. Different cases considered in case study

Bharatpur Metropolitan City, Office of Municipal Executive, Bharatpur Chitwan
Bharatpur is the fifth-largest and one of the fast-growing city
as well as a separate Metropolitan authority in the centralsouthern part of Nepal. It is a district headquarter of the
Chitwan district. One of the major responsibilities ofmetropolitan is to implement building code, issuing building
permit certificates, and monitoring constructions work.

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A study on seismic performance and retrofit approachfor current RC buildings with soft first story in Nepal
Phadera DHIRA
Engineer, Department of Urban Development and Building Construction (DUDBC), Nepal
E-mail : phaderadhira@gmail.com

Haruhiko SUWADA (Supervisor)
International Institute of Seismology and Earthquake Engineering, Building Research Institute,JAPAN

A combination of RC shear and wing wall as retrofit technique controls
excessive drift keeping the usability of open space in the first story.
The soft first story RC buildings proved to be vulnerable in Nepal during the 2015 Gorkha earthquake. The RC
buildings in Nepal are constructed with a weak frame, lack of ductile detailing, and brick masonry infill. In the city
area, due to urbanization and lack of land area, the upper story is used as brick masonry, and the first story isused for shopping and parking purpose. This research intended to assess and compare the seismic vulnerabilities
of RC buildings with soft story in Nepal namely, (i) building constructed by following NBC 205:1994 i.e. Mandatory
Rule of Thumb (MRT) with poor detailing and modified later by adding story (NBC) and (ii) building constructedbased on modified MRT of 2010 recommended by DUDBC, with poor detailing and modified later by adding story(NBC+). Seismic performance is evaluated by JBDPA guidelines of seismic evaluation, FEMA-356 and theseismic response is predicted by NBC1994, and nonlinear static pushover analysis to each model and dynamic
analysis to the Gorkha Earthquake motion. The results are discussed in terms of story shear, capacity curve,
maximum roof displacement, inter-story drift and damage pattern. Retrofit by wing wall and shear wall is
proposed. The research found that seismic behavior, ductility demand, and inter-story drift pattern of RC building
with the soft first story are different from those of the bare frame. The soft first story suffered extreme inter-story
drift causing severe damage. Seismic vulnerability of both buildings before retrofit showed NBC+ building
performed better than NBC building. Both model buildings sustain Gorkha earthquake motion. It reveals that thebuildings collapsed during earthquake were of low concrete strength, poor detailing, lack of reinforcement
constructed before the application of NBC. A combination of RC shear wall and wing wall proved to be effective ineliminating stiffness differences and controls excessive inelastic lateral drift to keep the usability of open space inthe first story.

FiguresFig. 1. The soft first stories collapsed
in 2015 Gorkha Earthquake Nepal.

Fig. 2. Retrofit plan for the soft first story of model NBC+building. A combination of RC shear wall and wing wall
controls excessive inelastic drift to keep the usability of open
space.

Department of Urban Development and Building Construction (DUDBC), Nepal
DUDBC, under the Ministry of Urban Development, is responsible for thepolicy-making in realms of urban development, housing and building
construction of Nepal. Moreover, DUDBC is accountable for the
implementation of government urban development works, building
constructions projects, and research regarding new building technology.
Besides, it acts as a monitoring agency for the implementation of building
code.

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Earthquake Performance Evaluation of Typical Bridge Structure
Designed by a Force-Based Design Method in the Philippines
Robert Jay N. PANALIGAN
Department of Public Works and Highways-Bureau of Design, PHILIPPINES
E-mail : panaligan_robertjay@yahoo.com

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

Displacement-Based Design method is the new approach in evaluating theseismic performance of a bridge, which is more precise in terms ofassessing damages.
The Philippines is an archipelagic country consisting of large and small islands. It is essential to have link
structures like bridges. After a disaster like earthquakes, bridges must be maintained to give way for an effective
rescue operation and transporting of relief goods to the affected area. Most of the bridges in the Philippines werebuilt on designs using the old code, which is based on the traditional approach, the Force-Based Design Method.
In this method, demand and capacity are compared in terms of forces. Currently, the Displacement-Based Design
method is being recommended as the new approach in evaluating the seismic performance of a bridge, which ismore precise for assessing damages, in which the seismic displacements are selected as demand parameters.
In this study, the author tries to apply the Displacement-Based Design methods to an existing typical bridge in thePhilippines and to evaluate the damaged deformation capacity by Nonlinear Dynamic Analysis (Time History
Analysis).
In conclusion, the author extracts some earthquake displacement response characteristics of typical bridges in thePhilippines and suggests revised cross sections to improve the safety of the target bridge. Finally, the authorsummarizes analysis based on the results and clarifies the merits of the displacement-based design method.

Figures
Original
SectionCase 136-32mmφ bar

Case 2
18-25mmφ bar

Fig. 1. Analyses Model of the target model bridge.

24-32mmφ bar

Fig. 2. Details of the Original Sections and the
Revised Sections

Department of Public Works and Highways
The Department of Public Works and Highways (DPWH) functions as theengineering and construction arm of the Government is 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 forthe 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 thenational development objectives.

6Study of the bathymetric influence on tsunami propagation near
the coast of Esmeraldas by tsunami simulation and ray tracing
analysis
Michael LINTHON
Oceanographic Institute of the Ecuador Navy (INOCAR), Ecuador
E-mail : arturolinthon@hotmail.com

Shunichi KOSHIMURA (Supervisor)
International Research Institute of Disaster Science (IRIDeS), Tohoku University, JapanThe changes in the bathymetric gradient greatly influence the propagationof the tsunami wave in front of Esmeraldas
As a result of the subduction and other geological processes, there is the presence of some bathymetric features
which significantly change the gradient of the seabed near Ecuador, such as the oceanic trench and thesubmarine Esmeraldas canyon. The main purpose of this study was to give a better understanding of how thesealterations in the bathymetry affect the tsunami propagation by conducting ray tracing analysis and tsunami
simulations using different bathymetry data sources of GEBCO, ETOPO, and INOCAR, for local and distantevents along the Pacific and the coast of Ecuador. In addition, we conducted tsunami propagation simulation
using TUNAMI code with a nested grid system of six domains. We used general and high resolution bathymetricdata and analyzed the results in all six domains. From the results of both tsunami simulations and ray tracing
analyses, we evaluated the consistency between the directivity of the rays and the wave’s propagation forfocusing areas such as Esmeraldas. We observed a faster propagation of the wave due to the particularbathymetric profile of the canyon in front of Esmeraldas, which made the first wave arrive at this city; with thisresult we confirmed the effect of local bathymetry along the tsunami path. This study can be used as a preliminary
evaluation to determine the vulnerability of specific locations along the coast regarding the changes in the local
bathymetry and topographic submarine features.

FiguresFig. 1. Ray tracing simulation from a point
source in central Ecuador located near thecoast. Results show how the rays are trapped
inside the trench refracting back to the coast.

Fig. 2. Snapshot obtained from TUNAMI simulation
model after 22 minutes propagation in Domain 4.
From the results we observed a faster propagation of
the wave arriving first to Esmeraldas city.

Oceanographic Institute of the Ecuador Navy (INOCAR)
INOCAR is a government institution that is responsible for developing thehydro-oceanographic characterization of the jurisdictional and nonjurisdictional maritime territory of national interest, the elaboration of
nautical cartography, to monitor the oceanographic conditions and to givethe service of safety to navigation.
As a member of the Pacific Tsunami Warning System since 1976, it is theofficial institution in charge of the study and issuance of the tsunami alertin case of a threat to the Ecuadorian coast.

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Evaluation of possible locations of bottom pressure recorder for
the Colombian north Pacific coast, using tsunami travel times
and tsunami simulations
1.6cm

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Photo

Laura Alexandra GONZALEZ RODRIGUEZ
General Maritime Directorate, COLOMBIA
E-mail : lgonz.r1@gmail.com

Shunichi KOSHIMURAInternational Research Institute of Disaster Science (IRIDeS), Tohoku University, JAPANTo select a suitable Bottom Pressure Recorder (BPR) location forimprovement of the tsunami early warning system in the north Pacificzone of Colombia.
The Colombian Pacific coast is prone to earthquakes and tsunamis, as registered in 1906, 1942, 1958 and 1979,
in which most disastrous events were the 1906 and 1979 in terms of the casualties more than 1000 and 500,
respectively. It is necessary for the National Tsunami Warning Center to improve the process of early warning forthe populations in the coast of Colombia. In this study, we aim to provide a suitable location for a Bottom Pressure
Recorders (BPR) to provide timely alerts for the north Pacific Colombian populated areas. We evaluated thepossible locations of BPRs, which provide proper time to issue tsunami warning to the populated areas in thenorth pacific coast of Colombia. We made a preliminary analysis assuming an arrangement parallel to thesubduction trench and then an improvement considering the technical recommendations given by the Pacific
Marine Environmental Laboratory regarding the deployment of BPR. With the final arrangement of BPRs, we
conducted Tsunami Travel Times (TTT) calculations for far-field events, and tsunami propagation simulations with
TUNAMI code. Furthermore, we evaluated the effectiveness of BPR in case of local earthquakes. We classified
the possible locations into three groups according to the lead time between tsunami detection on the BPR and thefirst arrival to the Virtual Observation Point (VOP) near the most populated areas, as: (1) best, (2) good and (3)not good. We found the best location for the selected arrangement of BPR in latitude 4.909° N, longitude 80.06°
W, at the depth of 3,134 meters.

FiguresFig. 1. (left) Snapshot of tsunami propagation from a
Nicaragua case. (right) Comparison of simulated
tsunami waveforms for the first detection points within
the BPRs and VOPs near populated areas.

Fig. 2. (left) Calculated TTT for a far-field earthquakeof Kuril. (right) Final arrangement of BPRs andclassification for suitable location (green: best, purple:
good, and beige: not good).

General Maritime Directorate
The General Maritime Directorate (DIMAR) was established in 1984 as
the Colombian Maritime Authority in charge of executing the government
policy in this matter, with a structure that contributes to the strengtheningof the national maritime power, ensuring the maritime integral security,
the protection of human life at sea, the promotion of the maritime
activities and the scientific and technological development of the nation.

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