Tsujun Bridge at Yamato town in Kumamoto was built in 1854 to send water for agriculture, and it suffered damage during 2016 Kumamoto earthquake. Field measurement was conducted on the Tsujun Bridge to determine natural frequencies and damping constant of the structure. Ambient vibration induced by people jumping was observed using a velocimeter. Simplified cone penetrometer tests also were conducted in the vicinity of the bridge to determine the strength of soil around the bridge. Further, earthquake response during 2016 Kumamoto earthquake was estimated using the identified natural frequency and damping constant. The results showed that the maximum acceleration response during the earthquake was estimated as 1.2G.

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 This paper studies the variation of collapse mechanism of cantilever columns with variable cross-section subjected to horizontal cyclic load. The rigid plastic and elasto-plastic analyses of columns are performed based on the second order theory by using the rigid body – rotational spring models. The rigid plastic approach explains that the collapse mechanisms V and Y every half cycle in columns vary due to the PΔ effects and accumulated residual rotation of springs. The elasto-plastic analysis shows that the instability region exists between mechanisms V and Y. It is compared with the transition region S predicted by the rigid plastic theory. Finally, the instability transition region S of collapse mechanisms is discussed from the point view of seismic design of columns with variable cross-section.

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 This research focuses on the characteristics of earth pressure acting on the box-shape underground structure subjected the strike slip fault displacement.
 Firstly, centrifuge experiments were conducted to investigate the deformation shape of the ground, as well as the characteristics of earth pressure acting on the underground structure quantitatively during the fault movement. Then, numerical simulations, utilizing the 2D elasto-plastic FEM, were conducted to investigate the reproducibility of the external force and deformation of the underground structure.
 The results show the 2D elasto-plastic FEM can reproduce the deformation shape of the ground, earth pressure acting on the underground structure and deformation of the structure.

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 The typical damage pattern of plain concrete piers during earthquakes is horizontal gap at the cold joint of a pier and falling down of concrete pieces from the pier under the cold joint. It is necessary to develop a numerical analysis method suitable for plain concrete piers to evaluate their seismic safety against the future earthquakes. With this background, this study investigated the applicability of the refined DEM for the dynamic analysis of plain concrete piers. First, it was found that the original refined DEM has a problem of overestimating friction properties. Therefore, the method was proposed to accurately simulate the friction properties by just modifying the arrangement of springs. Next, a shaking table test of a plain concrete pier was simulated, and the analytical and experimental results were compared. In the analysis, five acceleration histories with different peak acceleration values were input. In the case of smaller accelerations where the specimen suffered slight failure, it was found that the horizontal dislocation and failure occurrence situation was simulated with good accuracy. On the contrary, in the case of larger accelerations where the specimen suffered severe damage, it was found that the failure occurrence situation was barely simulated. It was also found that the refined DEM underestimates the rotational angle for all cases.

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 The 2011 East Japan earthquake induced widespread liquefaction not only in Tokyo bay area but also in inland area of Kanto region, which damaged numerous residential houses and public buildings. A research project was conducted to develop the latticed walls and drains and their combination, which can be installed as measures to mitigate liquefaction of grounds of existed residential houses and buildings. This paper reports the results of three-dimensional dynamic effective stress analyses for reproducing the dynamic centrifugal tests, and parametric studies about the spacing of latticed walls combined with drains.

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 In order to improve seismic performance, it is important to prevent rapid strength deterioration of RC columns. In this research, longitudinal bars with partially large lug were proposed for improvement of strength deterioration of RC columns, and the cyclic loading tests for RC columns were conducted. As the results, large lugs could control the occurrence of bond splitting cracks on RC columns surface, and bond characteristics of longitudinal bars with partially large lug was well-improved. Furthermore, by large lugs, both ends fixed boundary condition was maintained, and buckling length was prevented from becoming longer. In consequence, buckling of longitudinal bars became hard to occur, and rapid strength deterioration was prevented. Based on this result, pushover analysis of RC columns was conducted using buckling length as a variable. As a result, it was found that a general model of reinforcement buckling model wasn't able to reproduce strength deterioration with the same amplitude.

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 During the 2016 Kumamoto earthquake in Japan, a series of strong motions struck the towns along the active faults. The vertical array observation system at KiK-net Mashiki site installed by NIED observed a number of strong ground motions near the heavily damaged area. From the comparing between the weak ground motions and the strong ground motions mentioned above, nonlinearity of subsurface ground can be seen. In this study, the degree of nonlinearity in the amplification of subsurface ground was estimated from the inverse analysis of observed records. Quantitative relationships between the shear strains and shear modulus were obtained by the proposed method.

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 Countermeasure of underground structures such as tunnels against fault displacement is not established in design, but several one are presented in some studies. In this paper, to verify the effect of those countermeasure constructions against fault displacement under various conditions of the displacement direction, parametric studies using 3D FEM are conducted, and the critical displacement direction and the most effective countermeasure for circumferential bending moment, shear force and axial force of structure are estimated. As a result, it is verified that the most critical direction of fault displacement and the most effective countermeasure depends on the evaluation force.

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 A simulation method for damage and restoration process of large-scale lifeline network has been proposed incorporating time required for restoration of damaged links explicitly. First, restoration time conditioned by the occurrence of link damage is formulated on the basis of damage rate and restoration time given for each link component. Restoration time of a link is then simulated taking account of associated uncertainty. Illustrative examples are shown for Osaki and Sennan-Senen water transmission networks in Miyagi Prefecture that were severely damaged in the Great East Japan Earthquake Disaster, 2011. The results of reliability analysis and simulated restoration processes are in good agreement with the actual damage and restoration process. Moreover, potential restoration patterns under the similar condition are demonstrated.

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 In the current seismic design, the safety of the road embankments is confirmed by comparing the analyzed sliding displacement with the allowable displacement. The sliding displacement is practically analyzed by the Newmark method. When the seismic response of the embankment is negligible, FEA is necessary to obtain the input acceleration (equivalent acceleration) to the sliding blocks. This study proposes a simple evaluation method of equivalent acceleration without conducting FEA, but with the simple analysis of SDOF model. The estimation method of equivalent SDOF system was proposed. With the proposed method, the sliding displacement which has the equivalent accuracy with the current seismic design can be estimated easily. Furthermore, the sliding displacement spectrum is proposed which express the effect of natural period, damping factor, yield coefficient and sliding coefficient of the embankment on the sliding displacement. Simple evaluation method of sliding displacement using the sliding spectra is also proposed.

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 In this paper, the difference of orbit characteristics of bi-directional input waves affecting the elastic-plastic response of structural models is investigated. The proposed method extends conventional 1D spectrum-compatible method to 2D, and shows how to match the random trajectory time histories, which is orthogonal in the horizontal plane, with the target bi-axial response spectrum. By extending the energy spectrum which represents the energy of input seismic motion, the concept of bi-axial energy spectrum is proposed. Using this spectrum, differences in input seismic energy is shown when acceleration trajectories of the waves vary. In addition, incremental dynamic analysis (IDA) was carried out for elasto-plastic structural model, causing excitation by bi-axial response spectrum-compatible accelerograms with different acceleration trajectories. As a result, there is tendency for using circular trajectory as seismic input to show conservative result of elasto-plastic seismic response analysis.

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 Liquefaction was investigated after the 6.8 Mw earthquake on March 24, 2011 (Tarlay earthquake) in Chiang Rai Province, Northern Thailand. Several investigations including soil boring, SPT, and SASW tests were carried out and the results were used to perform one dimensional wave propagation analysis using finite element method. The maximum acceleration of 0.206 g recorded in Chiang Rai was used as the input motion. The input motion was applied at bottom of soil column to observe soil behavior under seismic loading. The result shows that liquefaction could occur at shallow depth (0 to 16.5 m), which is also followed by settlement (1.8 to 4 cm) due to compressibility of soil during earthquake. The analysis result indicates that there is no significant dissipated pore water pressure on liquefied layer. The longer duration of liquefaction is identified on layer (SP-SM), which have the low SPT values. Excess pore water pressure from bottom layer might also concentrate at this layer. The concentration of excess pore water pressure may trigger the duration of liquefaction up to 50 seconds. In addition, the excess pore water pressure ratio linked to impacted depth warns that the soils with excess pore water pressure in range of 0.9 to 1 are possible to get worse impact if a stronger earthquake attacks this area in the future.

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 It is difficult to evaluate site amplification factor analytically because site amplification factor is affected by several factors such as three dimensional deep subsurface profile. Site amplification factors have been evaluated by spectral inversion using strong motion record in the previous study. Therefore, site amplification factor has not been evaluated precisely at sites without strong motion observation.
 This study aims at proposing a simple estimation method of site amplification factors by modifying the amplification factors assuming horizontally layered deep subsurface profile at the site of interest. Amplification factors at low frequencies and peak amplification factors were estimated both by the kriging method and regression equations in terms of peak frequencies of the amplification factors. Applicability of the proposed method was discussed.

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 In recent years, unsaturated backfill that groundwater level is in a deep position, result in different settlement from the behavior of the saturated ground, it has been frequently reported. However less research for settlement of unsaturated soil by seismic motion, the mechanism has not been elucidated. In this study, the relationships between the amount of settlement, degree of saturation and dry density have been assessed, to prepare a unsaturated model ground, by using a shaking table. It was confirmed two failure pattern for the unsaturated ground liquefaction and cracks. The possible is found the boundary value of the degree of saturation.

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 We propose the evaluation method of ground motion amplification factor considering the shear strength of surface ground and the peak value of earthquake motion on the basement. When the amplification factor of ground motion is evaluated, it is common to use such input parameters as the peak value of earthquake motion on the basement (PBA, PBV) and natural period of surface ground (T_g). In this research, the amplification factor can be evaluated by considering the degree of the ground nonlinearity expressed by the shear strength index of surface ground (K_f). In proposed method, the ground motion amplification factor can be evaluated by the same procedure as the conventional method. And the additional parameter required for the application of proposed method is only the parameter K_f. It is examined that the accuracy of ground motion estimation is improved by proposed method. If there is not the detailed soil investigations at site, K_f can be estimated by the simplified method which has been already proposed in past study. So, proposed method can be widely applied regardless of the amount of soil information at site.

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 In order to investigate the liquefaction characteristics of undisturbed and remolded samples which have the same specimen density and shear wave velocity, a series of undrained cyclic triaxial tests was performed. The high quality undisturbed samples were collected from alluvial sandy layer in Chiba City by Gel-Push sampling method. The remolded samples were prepared by dry tamping and wet tamping method to adjust the specimen densities at the same level as that of the undisturbed sample. The shear wave velocity, measured by trigger and accelerometer method during isotropic consolidation, of the remolded samples was confirmed to be almost the same as that of the undisturbed sample. The test results show that even though the same specimen density and shear wave velocity, the liquefaction resistance and the behavior during cyclic loading were different between the undisturbed samples and the remolded samples. The reasons for the difference may be caused by a cementation effect acting on the soil fabric by aging and/or an inherent anisotropy of the specimens.

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 City gas shutoff system in earthquake disaster can be modeled as a k-out-of-n system activating shutoff when observing SI values exceeding a prescribed criterion. In this study, performance evaluation is carried out in order to better manage trade-off between service continuity and shutoff. Monte Carlo simulations are conducted to generate a set of SI values, resulting shutoff status in accordance with the criterion and corresponding damage ratios using fragility function and pipeline inventory. The generated dataset is analyzed using contingency table and associated indices such as true positive rate, true negative rage, positive predictive value, negative predictive value and ROC. Practical examples suggest that shutoff criterion can be appropriately determined by considering level of earthquake-resistance of low-pressure pipe.

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 Applicability of machine learning techniques has been examined for estimation of damage of low-pressure gas pipelines and decision making of emergency shutoff of city gas supply. A number of observation patterns of SI values, damage rate and shutoff patterns was generated by Monte Carlo simulation. The relationships between SI values and damage rate in training data was learned using support vector regression analysis. The relationships between SI values and shutoff status was learned using support vector machine. The results using test data suggests that the applied techniques can be promising tools for representing non-linear relationships among those factors related to damage estimation and shutoff decision.

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 The Kumamoto Earthquake has caused extensive damage to a variety of facilities along ground ruptures that appeared along both the known and hidden fault zones. Moreover close to 500 millimeters of rain fell in the quake-hit areas on June 20 and 21, causing further extensive damage, highlighting the difficulty to cope with earthquake-flood multi hazards. This paper describes some unique features of ground deformations that appeared along the fault, and the effect of the heavy rain on some of these deformed grounds.

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 We performed a detailed survey of buildings in central Mashiki town, which was heavily damaged by the 2016 Kumamoto earthquakes. The percentage of severely damaged buildings (damage ratio) varies greatly within this small area. In order to analyze the cause of the heterogeneous distribution, we performed a microtremor survey to study the effect of the local site response on ground motions during the Kumamoto earthquakes. Our results show that the area where buildings were less severely affected has a thick sediment deposit with a low shear wave velocity of 70m/s. From a nonlinear earthquake response analysis, the lower frequency content caused by the shallow layer was dominant during the mainshock, and there were relatively smaller amplitudes at 1-2 Hz. We suggest that this nonlinear response was an important factor contributing to the damage distribution.

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 In the 2016 Kumamoto Earthquake in Japan, two severe ground shakings occurred consecutively on April 14 and 16 in the Kumamoto Region of Kyushu Island, Japan. Extensive damage to structure and infrastructures occurred across a wide region of Kyushu Island. Since the mainshock attacked some structures that had already damaged by the foreshock, it is very difficult to estimate the failure mechanism based on survey after the mainshock. In this paper, the damage of bridges on the plains and in the mountains are summarized and the failure mechanism of Kiyamagawa Bridge in Kyushu Expressway is estimated based on field survey after not only the mainshock but also the foreshock.

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 This study proposed new probabilistic approach to assess human losses due to tsunamis and applied it to the Yokosuka city. We conducted tsunami inundation simulation occurring from 7 to 8-grater magnitude earthquakes in the Sagami Trough off the Kanto region. Obtained expected values of human loss indicated that the tsunami risk much differ from place to place, several residential area have significant high level risk of human loss.

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 On March 11th, 2011, a gigantic earthquake of moment magnitude Mw 9.0, which is officially named “The 2011 Off the Pacific Coast of Tohoku Earthquake”, caused severe liquefaction damage over the long stretch of reclaimed lands along the coast of the Tokyo Bay. In response to this earthquake, liquefaction-induced soil subsidence map for the eastern part of Tokyo Bay area was immediately prepared by comparing a set of Digital Surface Models before and after the earthquake, and subtracting tectonic displacement. In this study, soil subsidence map is further extended to cover the west part of Tokyo Bay area and compared with ground subsidence measured just after the earthquake.

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 Local subsidence damage on the airport taxiway right over the ground nearby the underground structure occurred at Sendai airport during the 2011 off the Pacific coast of Tohoku Earthquake. Shake table tests of the 1g gravitational field were performed to make clear a mechanism of the subsidence damage. This study focuses on evaluation of volumetric strain of liquefied ground around the underground structure by using shear strain histories obtained by the shake table tests and correlation between experimental results and estimated values of subsidence of ground surface. As a result, local subsidence around underground structure could be evaluated by shear strain histories and subsidence estimated by using the accumulated shear strain was higher estimation accuracy against experimental results than by using the maximum shear strain.

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 This research develops the model of disaster responses for effective disaster activities. To create the model, the research analyze the responses of Ishinomaki city and Yabuki town during the 2011 Great East Japan Earthquake Disaster and that of Kumamoto city during the 2016 Kumamoto Earthquake Disaster. As a result, 48 kinds of disaster responses are analyzed. The 48 frameworks are applied to the responses of Joso city during the 2015 Kanto-Tohoku Heavy Rain Disaster. Then the results show that developed framework can be applied to both earthquake disasters and heavy rain disasters.

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 The coseismic crustal deformations due to the 2016 Kumamoto Earthquake are numerically obtained using GEONET data. We further estimate coseismic strains of ground from the deformation data. The seismic intensity due to the earthquake is also obtained with use of strong motions by K-NET, KiK-net and other observation systems. Both parameters of the coseismic strains of ground and seismic intensity are compared with damage data of civil engineering structures. This paper especially places emphasis on comparisons between the coseismic strains and damages to soil structures such as ground slope. It is concluded that coseismic strains of ground mainly caused damages to ground slope and the characteristic distribution of coseismic strains in space resulted from the source mechanism of the 2016 Kumamoto Earthquake that had a strike-slip fault plane (right-lateral) with the break spread to the northeast direction.

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 We investigated the stochastic characteristics of Fourier amplitude of observed earthquake motion which is assumed to be a stochastic process in the circular frequency domain. First we extracted the nonstationary characteristic of Fourier amplitude by calculating a smoothed Fourier amplitude using Parzen window filter. Dividing the Fourier amplitude by this smoothed one we could standardize the Fourier amplitude. The main theme of this paper was to discuss the stochastic characteristic of this standardized Fourier amplitude. We investigated the variance of the incremental difference of this standardized Fourier amplitude with different circular frequency interval and obtained that the variance was expressed as a power function of circular frequency interval. Based on this result we defined the normalized standard Fourier amplitude inclement by dividing the standard Fourier amplitude increment with respect to the circular frequency interval. We found that the probability distribution characteristic of this increment could be modeled by the truncated Levy distribution. Because this distribution possesses the stable nature we discussed a possibility developing an algorithm to generate a Fourier amplitude process as a stochastic process.

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 The 2016 Kumamoto Earthquake caused severe damage on structures such as houses at Mashiki Town in Kumamoto Prefecture. Authors conducted microtremor observation at various sites in Mashiki Town in order to discuss the relationship between ground condition and damage level of structures. H/V spectra and phase velocities were evaluated from the microtremor records and average S-wave velocities were also evaluated from the phase velocities. It was found that both peak frequencies and average S-wave velocities are low at most of the sites where structures were severely damaged. Site amplification factors at some sites were evaluated from the aftershock records obtained during microtremor observation.

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 Crustal deformation could be a significant disaster factor. To make the efficient counter plan, we need to simulate co-seismic crustal deformation and estimate damages. In the simulation, it is desirable to use crustal deformation observation data and crustal structure data at high resolution. In addition, uncertainties of inputs should be considered. In this study, we developed the analysis method of crustal deformation quantitatively considering uncertainties by MC (Monte Carlo) method. To handle massive computation cost, we developed the fast numerical simulation method of crustal deformation based on the finite element method with GPU (Graphics Processing Units) computation. We reconstructed the algorithm so that calculation in the analyses was suitable for GPU computation. By introduction of GPUs, computation time was significantly decreased and we enabled to perform simulations many times in a realistic time.

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 Buckling-restrained brace (BRB) has been proposed to absorb energy by plastic yielding of metallic core plate during an earthquake.
 As magnitudes of recent earthquakes increase, there is a potential that BRBs may rupture during a strong earthquake or repeated aftershocks, especially for bridge where large response displacement is concerned.
 This study is aimed at proposing a new type of light-weighted all-steel BRB, where the core plate is fish-bone shaped and is thus termed FB-BRB in this paper.
 Necking can be developed at several locations of an FB-BRB, and details to avoid strain concentration at stoppers are also proposed.
 Experimental study was carried out using four scaled specimens with different configurations.
 The failure mechanisms of the newly proposes FB-BRB have been verified, and favorable seismic per-formance of the dampers is also proved through comparison with that of a common BRB.

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 The present study is aimed at investigating effects of various structural parameters on the strength and ductility of bridge piers made of high strength steel SM570 material. Main parameters considered are flange plate with-thickness ratio, column slenderness ratio and axial force ratio. For this purpose, an elasto-plastic cyclic analysis is carried out, and the modified two-surface model is employed. Based on the analytical results, discussions are focused on if it is possible for steel piers made of SM570 material to apply some of existing formulas for determining the strength and ductility of steel piers made of SM490 material. As a result, new formulas are proposed with good accuracy for determining the strength and ductility of steel piers made of SM570 material.

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 In this study, a three-dimensional simulation of the Aratozawa landslide due to the 2008 Iwate-Miyagi Inland earthquake based on the Smoothed Particle Hydrodynamics (SPH) method were conducted. The numerical results were compared with the observed damages especially with respect to the flow distance of the landslide. In order to obtain the material strength parameters used for the simulation, the field survey and the laboratory test were performed. The numerical results by the SPH method showed good agreement with the maximum flow distance caused by the 2008 Aratozawa landslide.

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 In the present study, a numerical method for analyzing the performance of an earthquake-resistant stone masonry retaining wall is developed. The Smoothed Particle Hydrodynamics (SPH) method and the Distinct Element Method (DEM) are combined in the developed method. In order to verify the developed method, a series of laboratory tests of earthquake-resistant stone masonry retaining walls are analyzed. The effectiveness of a ground reinforcing material are reproduced qualitatively by the developed method, however improvement is still required.

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 Recently, large scale inland crustal earthquake have occurred frequently in Japan, and some of them have surface rupture. Existence of surface rupture significantly affects on ground motion characteristics, however, inland crustal earthquakes in Japan have been not previously analyzed except for the 1995 Kobe earthquake. In this study, we analyzed difference of ground motion characteristics between surface and buried rupture earthquakes in Japan. Ground motion characteristics were evaluated from deviations of observed response spectra with average response spectra calculated from a spectrum attenuation relationship. As a result, ground motion from buried rupture earthquake is two-times larger than those by surface rupture earthquake in frequency range between 0.1 and 0.4 seconds.

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 Axial soil spring between the pipe and ground is treated under the assumption that only a static friction acts. A simple coulomb friction is used in many of seismic response analysis on the buried pipe. In this study, the velocity dependency of shear stress between the pipe and ground was tried to make clear by the real-scale pipe pulling-out test using the shaking table. As a result, it has been understood that the maximum shear stress are different about twice depending on the pipe-moving velocity, and the maximum shear stress and the sliding characteristics are different by the ground compacting condition.

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 In excess pore water pressure dissipation method as a countermeasure against liquefaction, it is pointed out that there is no “tenaciousness” because the effects to reduce excess pore water pressure ratio are lost if level of earthquake intensity exceeds expected scenario. However, the disaster mitigation effects of earth structures such as quay walls using artificial drain material were observed during large scale earthquake such as the 2011 off the Pacific Coast of Tohoku Earthquake. In this study, in order to reveal “tenaciousness” of the effects to reduce the deformation of the improvement ground using artificial drain material during earthquake, the effective stress analyses using the strain space multiple mechanism model with permeability were conducted for sloped grounds which are representative earth structures.
 Based on the results of this study, it was found that “tenaciousness” of the effects to reduce the deformation of the improvement ground using artificial drain material remained tough condition even if the earthquake exceeded the scenario, by normalizing residual horizontal displacement of improvement ground with respect to that of unimproved ground and nonliquefiable ground.

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 The damage investigation of the water tank of the Great East Japan Earthquake and the Kumamoto earthquake, cases of the side plates and the corner portion of the lower side is damaged from the case and the center where the ceiling and the upper part of the side plate was damaged was observed. The former is caused by the sloshing vibration, the latter is caused by bulging vibration. In this study, using the FRP panel water tank of 3m × 3m × 3m, it was verified for the bulging vibration. As a result, than the change of displacement and pressure of the wall, to confirm the range of the generated frequency of bulging. Bulging is quickly vibrate vibration is completed it was confirmed that convergence. Bulging is to generate a large pressure at the bottom of the tank, this is the cause of the damage to the tank.

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 Evaluation of seismic performance on buried pipeline changes whether the pipe slips against the surrounding soil or not. When slippage takes place, stress and strain concentrate to junctions and bends. Important factors of slip or not-slip are critical shear stress of soil (τ_cr) and elasticity of pipe materials. Previous experiments by our group have shown that polyethylene pipe (HPPE) does not slip in the soft ground during severe earthquake. By contrast, HPPE slips a little in solid ground because of the short wavelength. In this study, we estimated the influence of slippage against junctions and bends. Our results are as follows: (1) τ_cr of HPPE with accessories including a coupler and branch saddle is 10.8kN/m² - 19.5kNm² because these accessories function as resistance in the soil. (2) Maximum slippage of HPPE is approximately 12.5mm in the solid soil. (3) we confirmed that there are no leakage from the branch saddle and the strain acting on the pipe with accesories and bends is enough small even in case HPPE slips. Through this study, the evaluation of seismic performance on polyethylene pipeline as the water pipeline were completed.

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 In Japan, a lot of natural disasters are expected to occur with a high probability in near future. After a major disaster, relief supplies can't get immediately. Therefore, self-help and mutual assistance of inhabitants are more important than public aid. It is worth considering food of the household during daily life, but not stockpiling of food for disaster. However, there have been few studies about the amount of the food of the household. The purpose of this study is to examine self-help and mutual assistance of inhabitants using the food of household during daily life.
 Questionnaire survey were conducted in Kanazawa City, Ishikawa Prefecture, and in Adachi Ward, Tokyo. As a result, there are more food in Kanazawa than Tokyo. Moreover we carry out the food simulation considering Nankai Trough earthquake. As a result of the simulation, total calories of meat, seafood, and vegetables are short of calories which are necessary to refuge life per day. However, there exists large quantities of grain, especially rice. They are calories which necessary for 4-8 days. These foods can be used for self-help and mutual assistance during disaster.

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 This study aimed to establish a method for evaluating coastal parapet levees' seismic coefficients taking their dynamic characteristics under level-1 earthquake's loads into consideration. Two methods were applied to parapet levees, which are the method to estimate the natural frequency using frame analysis and the method to estimate the maximum acceleration during earthquakes using acceleration response spectrum, and the validity of those methods for the coastal parapet levees which have pile foundations was verified. As a result of study, the applicability of those methods was examined. Expecting the extreme large earthquakes, the maximum acceleration of coastal parapet levees during earthquakes was estimated with a high precision using the natural frequency calculated by the frame analysis and the acceleration response spectrum calculated by the one dimensional dynamic response analysis.

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 Couple of rubber bearings on highway bridges were damaged by 2011 Tohoku Pacific Offshore Earthquake. Even though the seismic design using the rubber bearings has been widened since 1995 Kobe Earthquake, the residual seismic performance of the rubber bearing which were experienced great earthquakes as like the above great earthquakes has not been identified. In this study, in order to investigate the residual seismic performances of Rubber Bearings (RB), Lead Rubber Bearings (LRB) and High Damping Rubber-super (HDR-S), load-displacement hysteresis, equivalent stiffness, equivalent damping, cyclic loading tests using 3 test pieces per each type of rubber bearing were conducted. No. 1 was subjected to axial force with 6MPa and 100 cycles lateral loadings with shear strain of 250%. No. 2 was subjected to the axial force with 1MPa and 100 cycles lateral loadings with the shear strain of 250%. No. 3 was subjected to the axial force with 6MPa and 100 cycles lateral loadings with the shear strain of 150% and the axial force with 6MPa and 10 cycles lateral loadings with the shear strain of 250%.

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 Couple of rubber bearings on highway bridges were damaged by 2011 Tohoku Pacific Offshore Earthquake and 2016 Kumamoto Earthquake. Even though the seismic design method using the rubber bearings has been widely used since 1995 Kobe Earthquake, the vertical and shear properties of the rubber bearing has not been identified due to lack of related experimental studies. In this study, in order to investigate the shear behavior and shear properties of Rubber Bearings (RB) subjected to tensile force, cyclic loading tests using 4 test specimens of RB were conducted. To evaluate the shear properties of RB, here in, the tests varied with axial stress were carried out. Furthermore, to evaluate the influence of the primary shape factor (S₁) which was defined in the design code of bearing support on the shear properties of RB, the cyclic loading tests using a different specimen of S₁.

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 At the time of earthquake occurred, the important road section such as the emergency transportation road is likely to impassable. Because of this reason, it is assumed that bad influences such as the detour or the isolation will occur. Consequently, it is important to evaluate the road section vulnerable to earthquakes. In this study, an evaluation method of the vulnerable road section to the earthquake of the road network is developed and it applied to evaluation of the vulnerable road section of emergency transportation road network. As a result of this analysis, the utility of this method became obvious.

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 The recent 2011 off the Pacific coast of Tohoku Earthquake earthquake and tsunami generated huge tsunamis, and many protective facilities were destroyed. Most of the damage was caused by tsunami overflow. After a main shock occurred, many aftershocks occurred. As for the possibility that a structure suffered from by the superposition phenomenon of an earthquake and the tsunami, it is thought. A large-scale hydraulic model experiment was conducted to confirm it about the influence on breakwater in the superposition of an earthquake and the tsunami, and residual horizontal displacement. In superposition of an earthquake and the tsunami of the breakwater, it was affected by the tsunami and confirmed that different residual displacement was produced only in the case of an earthquake. As a result, at an earthquake and the compound action of tsunami overflow, it clarified that there was a tendency to reduction effect of the acceleration and increase of the horizontal displacement.

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 In this paper, the influence of soil uncertainty on hysteresis characteristics is evaluated by applying a stochastic elasto-plastic model to simulate the stress-strain relation of undrained clay. The stochastic model is based on stochastic return mapping algorithm which is expanded by spectral expansion. It is shown that the stochastic approach can evaluate more realistic hysteresis characteristics, even with elastic-perfectly plastic von Mises model. The uncertainty of dynamic deformation characteristics is estimated by calculating the influence of soil uncertainty on the response fields.

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 In this research, non-linear model named Double-Target-Tri-Linear for LRB considering Mullins effect and Hardening is proposed based on the product inspection results at release. All bearings are made of ‘G10’ stiffness rubber, but shapes of the bearings are various. Parameters using in Double-Target-Tri-Linear model were evaluated from the results.
 And seismic performance of a single pier model of highway-bridge was compared using the proposed model with bi-linear model. From the calculated results, the effect of difference of each model was relatively large in the case that the pier deforms up to plastic range. Displacement of the LRB was reduced by considering Mullins effect and hardening, but response of the pier base tended to increase.

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 In the Hamaoka Nuclear Power Station, we constructed the tsunami protection wall along coastline around the site, following the tsunami disaster of The 2011 off the Pacific coast of Tohoku Earthquake on March 11, 2011.
 It is general design procedure to utilize the Westergaard equation in case of designing the wall structure such as the tsunami protection wall even in consideration of hydrodynamic pressure. However there is an issue to apply the Westergaard equation in our case. Because the Westergaard equation could be essentially applied for only the rigid wall, however the seismic behavior of the tsunami protection wall is considered to be elastic oscillations and also the depth of tsunami in front of the tsunami protection wall is fluctuant due to the effect by the dune embankment along coastline. Therefore, we implemented the geotechnical centrifuge experiment modeled with the tsunami protection wall as well as the actual coastal topography, and performed the simulation analysis. As a consequence of the experiment, we revealed that the hydrodynamic pressure acting on the wall shaking elastically in the upper side of wall, which receives the amplification of shaking, has a substantial difference comparing to the case of the rigid wall. Also, as the result of the simulation analysis, we revealed that both the added mass model based on Westergaard equation and the liquid element model have applicability to the simulation but the liquid element could be better to represent the hydrodynamic pressure more accurately.

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 As the characteristic of Isolation bearing using for bridges changes according to various factors, the seismic behavior sometimes occurs different from the behavior expected in design. In this paper, we studied the influence gotten by the reduction of bearing stiffness due to dependence factors and investigated the effect derived by hardening characteristic of rubber bearing. Furthermore, we researched the influence to LRB induced by the over strength of RC pier. As a result, the share deformation ratio of LRB is apt to approach to the crash share deformation ratio, but we certified that it was reduced by hardening characteristic in high share deformation range. On the other hand, the over strength of RC pier doesn't influence so much to seismic behavior of LRB which pier yields a little in seismic design.

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 This study, in assessing the seismic shear stress ratio L of the assessment method of liquefaction based on F_L, is investigated the method to consider the influence of the earthquake motion characteristic and the amplification characteristics due to the nonlinearity of the surface ground.
 In this paper, in order to expand the application scope of the assessment method of the seismic shear stress using the earthquake motion record on ground surface that authors proposed, we investigated a simplified assessment method based on surface earthquake record about the reduction rate of S-wave velocity of surface ground by strain dependence.
 Furthermore, performed a regression analysis from the relationship between the calculated reduction factor of seismic shear stress by the proposed method by using a lot of strong motion observation records, and Indicators of surface earthquake motion and the ground. And, assembled a regression formula for estimating the reduction factor r_d of seismic shear stress.

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 The 2016 Kumamoto earthquake was occurred by the active fault which has been evaluated by the Headquarters for Earthquake Research Promotion. The magnitude of the main shock that caused severe damage on structures at Mashiki Town in Kumamoto Prefecture was M_JMA 7.3, but, the magnitude of the Futagawa segment of Futagawa fault zone through the Mashiki Town has been evaluated as M_JMA 7.0.
 In this study, estimated ground motion based on the information of the active fault was compared with the observed ground motion by the main shock at the KiK-net Mashiki site.
 In conclusion, the level of spectrum of estimated ground motion is close to the observation record, but it is lower than observation record at around 1 second period.

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