In southern Thailand, Phuket was one of six provinces heavily affected by the 2004 Indian Ocean Tsunami. Patong is one of the most populated beaches in Phuket province. There are not only outdoor activities on the beach, but people can also enjoy several indoor activities, such as shopping, eating, massaging, etc., across the area. Therefore, population distribution can be implied by these activities related to the building occupancy classes, such as hotels, restaurants, shops, etc. Generally, tsunami evacuation simulation begins with a model of the departure locations, also known as population distribution. For example, individuals initially depart from each building uniformly distributed or based on the building occupancy classes (BDOC), such as residential, hotel, commercial, etc. The number of occupants for each building class can be assumed based on expert judgment or the field survey. In this study, we focus on the effect of population distribution on tsunami evacuation using agent-based modeling and simulation. The population in Patong, Phuket province is estimated based on the unit area of each building's occupancy class and the building’s floor area (m²). The results show that the population in commercial buildings based on the Uniform model is significantly less than in the BDOC model. The BDOC model causes faster evacuation than the Uniform model, which may be caused by the high population being closer to safe places, such as tall buildings. Population distribution significantly affected the tsunami evacuation and should be taken into consideration.

A S M M Kamal, Professor, Department of Disaster Science and Climate Resilience, University of Dhaka, Bangladesh

S. Shahid, Associate Professor, Department of Water & Environmental Engineering, School of Civil Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, Malaysia

A K F Fahim, Research Associate, Department of Disaster Science and Climate Resilience, University of Dhaka, Bangladesh

Kofun tumuli, one of Japan's representative historical heritages, are massive tomb mounds built around 3~7 century, using Japanese ancient civil engineering techniques. One of the methods used in the construction of kofun tumuli is interlayered structure of soil with different grain sizes, such as clay and sandy soil. In this study, the reason for adoption of the interlayered structure of fine-grained and coarse-grained soil is interpreted from a modern geotechnical engineering perspective. Based on archaeological and geotechnical engineering research methods, the interlayered structure soil was reproduced using silica sand No. 3 to No. 9 and silica sand powder, based on the grain size accumulation curves for clay and sandy soils in the excavation report for the Miyakozuka Kofun, Nara Prefecture ^[2]. Triaxial compression tests and sand box tests were conducted to determine its shear and seepage characteristics.

Triaxial compression tests were conducted to investigate the compressive strength of the interlayered structure of fine-grained and coarse-grained soil. The cylindrical specimen (Figure 1, left) was 50mm diameter and 100mm length, under a confining pressure of 50 kPa.Sand box test was conducted to investigate infiltration characteristics of the interlayered structure of fine-grained and coarse-grained soil. The interlayered structure was placed with a thickness of 10cm, and inclined at a 10° angle. Rainfall was applied from the top of the sand box. The flow rate through the surface, the amount of water drained per layer and the time when the outflow was confirmed were measured.

Triaxial compression test showed that the strength of the interlayered structure was about the same as that of the single-layered fine-grained soil.(Figure 2). This is because the fine-grained soil layer preceded the coarse-grained soil layer in strain. The result of triaxial tests suggests that the interlayered structure was not used for the purpose of increasing the strength of the mound.Sand box test showed that rainwater infiltrating into the mound might flow outward along the slope, mainly through the coarse-grained soil layer, preventing the deterioration of the fill due to rainwater infiltration.The interlayered structure of fine-grained and coarse-grained soil adopted in Kofun was found to combine the permeability of the coarse-grained soil layer with the impermeability of the fine-grained soil to prevent rainwater from penetrating into the center of the mound.

Slope failure is an important disaster that should be taken into consideration, such as slope failure of highway slopes that have a large negative impact on society and slope failure that occurs near residential areas that can cause loss of human life. This study was initiated to investigate the shear properties of a mountain slope composed of volcanic soil at an elevation of about 1,400 m, where a landslide occurred in the past. However, we experienced the difficulty of carrying the undisturbed sample back to the site because of the 2.5 km long uphill and downhill mountain road and the water spewing from the disturbed sample that we brought back. Therefore, a testing machine was fabricated to conduct in-situ tests with less disturbance to the site-specific soil structure.

Buildings in central business district (CBD) of Yangon have been closely situated, very less or almost no gap. Moreover, due to the economic and construction development, many mid-rise buildings have been constructing in sub-urban area of Yangon. In Nov 2019, mid-rise buildings tilting and leaning problems, after slight earthquake of magnitude 4.1 Richter Scale with its epicenter near Yangon, have been reported in sub-urban areas. It highlighted the need of vulnerability assessment and importance of separation gap.

Two cases of adjacent RC building condition are considered in this analysis (Fig-1); case 1 (8-story next to 7-story) and case 2 (6-story next to 5-story building). Three different base conditions; fixed, SSI base (Vs 150 m/s) and SSI base (Vs 250 m/s), are considered under Northern Calif-03 earthquake event. Nonlinear time history analysis is carried out using the scaled ground motion that matched the target spectrum of Yangon.

The result shows that separation gap required to avoid pounding-induced damage seems to be affected by SSI. Soft soil case (V_s 150 m/s) exhibits the maximum displacement response for all building. In both adjacency cases, conventional fixed base analysis will underestimate the required clear distance between adjacent buildings and will lead to pounding during shaking. There is phase variance in displacement responses for different base conditions. Effect is prominent for 8-story building as shown in Fig-2. This may be due to the interaction effect between soil and foundation. Therefore, SSI effect should be accounted in estimating the behaviors of structures during earthquake. This study takes into account only one ground motion and it is planned to consider a large number of ground motions for general assessment in the future. Inventory of pounding potential building types can be a useful information for urban planning, limiting separation gap requirement and prioritization of retrofitting.

The intensity of ground motion mainly depends on the source, source-to-site distance, and local site condition. Depending on the local geology of the site, the seismic ground motion could be amplified or de-amplified to reach the surface. To accurately measure the acceleration of surface ground motion, site response analysis is mostly used. In this study, one-dimensional nonlinear site response analysis is performed based on the prepared engineering geomorphic unit map of the Dhaka DAP area. The engineering geomorphic unit-based map was prepared from image analysis and verified with the boreholes data. For response analysis, the earthquake time histories are selected from the PEER NGA WEST2 data set, and BNBC 2020 uniform hazard spectrum (UHS) is considered as the target spectrum. Moreover, two synthetic time histories are generated and used for the site response analysis. We observed that, for the selected earthquake ground motions, the near-surface soil response of the DAP area shows de-amplification of acceleration in the short period and amplified acceleration in the long period. The outcome of this study can be used to prepare a seismic risk-sensitive land use plan for the future development of the DAP area of Dhaka.

The Koedo Kawagoe Ichibangai shopping street in Saitama Prefecture, is designated Important Traditional Building Preservation Areas, where many tourists visit, especially on holidays. However, there are several off-street parking lots along the street. This causes problems with the fragmentation of the streetscape, the influx of cars into the shopping area and the confusion with pedestrians near the entrances and exits of the parking lots.

In Japan, the number of traffic accidents caused by elderly drivers is increasing. The National Police Agency of Japan requires elderly drivers over the age of 75 to　have a cognitive impairment test to check their ability of driving aptitude. However, it is difficult to prevent the occurrence of traffic accidents among the elderly by these measures alone. It is necessary for each elderly driver to understand his or her own driving skills and to take appropriate measures.

In this study, a recurrence plot was created from driving behavior data, and a deep learning image recognition technique was applied to detect abnormal driving.

Unreinforced Masonry (URM) houses contribute to massive casualties during earthquakes. Moreover, the URM house model has been widely built in seismic-prone areas in developing countries. Concrete Hollow Block (CHB) has recently become a popular material for residential houses because of its affordability and versatility. However, due to bad implementation, CHB as a masonry unit has low compressive strength and is weak against the lateral load. Therefore, improving the seismic capacity for masonry houses has been the most urgent issue in recent years. This study used fiber-reinforced paint as retrofitting material to increase the seismic capacity of masonry houses. Other advantages of fiber-reinforced paint are that it is easy to apply, minimizes dust during earthquakes, and is commonly used to beautify house appearance. This study discusses diagonal tension (shear) tests on full-scale CHB masonry assemblages. From the results, fiber-reinforced paint can improve the deformation capacity of masonry houses.

1. INTRODUCTION
Damage caused by aging public infrastructure is a
a growing problem in Japan, and it is necessary to detect
internal damage in concrete structures before it surfaces.
One of the non-destructive inspection methods for
concrete is the electromagnetic radar method, which is
based on the amplitude and intensity of the received signal,
called B-mode (Figure1.)[1]. Since this method is
subjective and requires the skill of the person in charge of
the inspection, it is desirable to be able to estimate the
damage automatically and with high accuracy. Therefore,
the objective of this study is to establish an algorithm to
estimate the void thickness in concrete accurately and in
real-time.

2. ALGORITHM FOR ESTIMATING THICKNESS
As the void thickness decreases, it becomes impossible
to distinguish its peak due to the subtractive interference
caused by the upper and lower reflected waves. Therefore,
we focused on the frequency response because the
reflected wave has a frequency dependence depending on
the void thickness change[2]. Figure 2. shows the
spectrum for different void widths, and since the spectrum
also changes as the void thickness changes, we thought
that the void thickness could be estimated by performing
pattern matching of the frequency spectrum.
Figure 3. shows the results of applying the algorithm to
20mm and 110mm rectangular void. In addition to
spectral matching, information on the extreme values of
the time waveform and comparison of the spectral
the centroid of the theoretical value with that of the measured
value enables highly accurate estimation of the void
thickness at a lower computational cost.

3. CONCLUSIONS
By focusing on both the frequency response and time
the waveform of the reflected wave, I succeeded in
quantitatively estimating the void thickness even with a
very weak signal compared to rebar.