A damage identification technique using high-frequency excitation based on the spectral element method is presented. Considering a drawback of the low-frequency-based damage identification technique, this study proposes a damage identification technique using kHz-level frequency that can detect smaller damage efficiently. It is assumed that the structure is excited with a harmonic force by a piezoelectric actuator and that the method focuses on the difference of the frequency response function by damage. Moreover, it uses the spectral element method that is suitable for analyzing structural responses at high frequency domain. The effectiveness of the proposed method was verified by numerical simulations for the steel truss bridge.

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 Under an extreme ground motion, flexural capacity of a RC column deteriorates due to crushing of the core concrete and buckling of longitudinal bars. Therefore, it is important to prevent damage at the plastic hinge region for enhancing the seismic performance of RC columns. Two UFC segment columns which use UFC segments at the plastic hinge region and unbonded longitudinal bars are proposed; 1) in-core RC type column, and 2) PC cable type column. The seismic performance of two columns were clarified based on cyclic loading experiments. It is shown that the in-core RC type column shows better performance than the PC cable type column.

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 It is always an argument whether we can predict response and failure mode of prototype structures based on scaled model experiments. In this study, the effect of maximum aggregate size and evaluation of rebar section area on the seismic performance of RC bridge columns was investigated. It is shown that crush of core concrete is more significant in the scaled model which was constructed using concrete with the maximum aggregate size of 5mm than that with 13mm, and that the moment capacity of the prototype column can be well predicted based on the scaled model in which the minimum rebar section area is used. However progress of damage of the prototype column such as spall and crush of core and cover concrete occurred more significantly in the prototype column than the scaled model columns.

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 Flexible reinforced concrete piers with I shape section are flexible along bridge axis. These piers are characterized by their abilities to absorb earthquake energy through shear wall. The purpose of this paper is to study the fracture behavior, restoring force characteristic and the ability to absorb energy through the horizontal load experiments for scale models of flexible reinforced concrete piers with I shape sections. It assumed that the piers behave as shear bending members with central pillar and side walls, and four polyline type are proposed compounding bending and shear effects. When comparing theoretical value with experimental results, it is clear that although the load bearing ability is estimated with enough accuracy, but it is necessary to make improvement.

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 When the structures, for example arch bridges are subjected bending moments and torsional moments, the strength and rigidity of the members decline compared to those of pure bending or torsion load condition. However, any analysis soft don't consider interrelation between bending and torsion ,and effects of torsional moments have not been considered severely in seismic design.
 In this study, the authors proposed analysis technique considering interaction between bending and torsion to estimate torsional moments severely, and formulized the analysis tools for this technique. These are interaction curve, skeleton for combined load, hysteresis for torsion. Moreover, the authors analyzed a RC arch bridge using this method, and inspected the validity of comparing the results obtained equivalent linear analysis about torsion and nonlinear torsional analysis not considering the interaction between bending and torsion.

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 A novel idea of a high seismic-performance RC column which is expected to remain undamaged against strong earthquake motions is presented. A larger elastic deformation capacity can be achieved by dividing vertically a rectangular column into several column components, while friction material interfaces between the column components with horizontal confining forces provide energy dissipation capability to the column. In this study, static loading tests of a test specimen of the proposed RC column are carried out. It is shown that each column is within the elastic range up to 2% drift and the restoring force is fairly constant up to 10% drift in the plastic region. These results show the expected hysteretic behavior in the elastic range and preferable ductile behavior in the plastic deformation range.

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 The pile foundation is heavily damaged at the boundary division of the ground types, liquefied ground and non-liquefied ground, during an earthquake and there is a possibility of the collapse of the piles. In this study, we conduct a shaking table test and effective stress analysis of the influence of soil liquefaction and the seismic inertial force exerted on the pile foundation. When the intermediate part of the pile, there is at the boundary division, is subjected to section force, this part increases in size as compared to the pile head in certain instances. Further, we develop a seismic resistance method for a pile foundation in liquefaction using seismic isolation rubber and it is shown the middle part seismic isolation system is very effective.

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 Pile foundations are often used to have enough vertical bearing capacity of structures on soft ground. However, in many case, large size foundations are needed to support inertia force of superstructures. On the contrary, such inertia force can be reduced by adapting spread foundations in spite of pile foundations, since seismic wave can be reduced between ground and foundation, due to base isolation and plasticity of ground, although spread foundations may show larger settlement compared with pile foundations.
 In this paper, we have proposed spread foundation with ground improvement, which have both base reduction effect and sufficient vertical bearing capacity. Result of shaking table tests confirmed such advantage of proposed method. Additionally we have developed the analytically method, which can simulate seismic behavior of spread foundation with ground improvement.

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 In this study, A substractured pseudo-dynamic simulation system for low-temperature environment is developed. The developed system utilizes an open-source pseudo-dynamic system UI-SIMCOR and a sub-program which can cooperate with existent loading facility in a cold room is developed. To enhance usability of the system, another sub-program is also developed for application of general FEM software.
 A simulation for a simple girder model with seismic damper is performed. Dynamic response of the damper is obtained as a part of whole structure and friction type displacement-force hysteresis curve is properly obtained. The maximum displacement is reduced 80% by energy dissipation of the damper. The result of the simulation is not affected by low temperature because the damper is stable to lowtemperature as shown in previous studies.
 Hence, the system is able to work properly as a substructred pseudo-dynamic simulation facility at a low-temperature environment. For farther development, velocity control of loading equipment will improve accuracy of simulation results.

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 Recently, high acceleration and high frequency near-field vertical ground motions were recorded at several sites. The extreme vertical ground motions can induce high frequency varying axial force which develop even tensile force in reinforced concrete bridge columns. Cyclic loading experiments of RC columns were conducted to clarify the seismic performance of RC bridge columns under near-field vertical ground motions. It is shown that core concrete is crushed extensively due to varying axial force after longitudinal bars buckle.

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 In this study, static cyclic loading tests, uni-directional hybrid tests, uni-directional nolinear seismic simulation using curve approximate hysteretic model developed for steel piers and bi-directional hybrid tests are conducted to clarify the seismic performance of steel bridge piers under bidirectional ground motion excitation. Nine bridge models applying 3 types of bridge pier specimens and 3 ground type conditions are designed based on the current seismic design specification. The response of these bridge models under uni- and bidirectional ground motions are obtained by pseudodanamic tests and numerical simuations. By comparing these tests and simulation results, it is found that the bridge piers could be collapsed under bi-direction ground motions, which are regarded as safe under uni-directional loading. Under the bidirectional seismic action, the capacity of steel piers degrades to averagely 84%, and their response displacement increases 20% more than the values obtained by convential uni-directional loading.

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 It is necessary that nonlinear responses of structures are clarified by soil-structure interaction analysis for the purpose of evaluating the seismic performances of underground structure or foundation structure. In this research, centrifuge shake table tests of reinforced concrete pile foundation installed in the liquefied ground were conducted. Then, finite element analyses for the tests were conducted to confirm an applicability of the analytical method by comparing the experimental results and analytical results.

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 Recently, it is desirable that nonlinear responses of structures are clarified by soil-structure interaction analysis, especially for evaluating the seismic performances of underground structure or foundation, due to a severe seismic action is expected for the seismic design. In this research, centrifugal vibration tests of reinforced concrete box culvert under severe earthquake was conducted, firstly. Then, finite element analysis for the test was conducted to clarify an applicability of the analytical method. By comparing experimental results and analytical results, it is confirmed that reasonable non-linear responses of both ground and RC box culvert were reproduced by the analysis.

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 The Uplifting Slide Shoe (UPSS) is proposed as one of the method for upgrading the seismic performance of multi-span continuous girders. UPSS transfers the kinetic energy to the potential energy in the vertical direction by sliding girders up on the inclined slope during earthquake, and restricts horizontal displacement. This study is aimed at grasping the energy transferring during earthquake using UPSS. A basic dynamic problem was examined by using single mass system in this paper. The result shows that the horizontal energy was temporarily transferred to the potential energy of UPSS and the strain energy of the superstructure, and was reduced steady by friction and viscous damping.

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 The Uplifting Slide Shoe (UPSS) is a type of bearing proposed to deal with the thermal expansion and contraction of bridge girders, to disperse the seismic horizontal forces to multiple columns and to control horizontal displacement response of the continuous girder bridges. In this study, a combination of the UPSS bearings and seismic dampers for girder bridges is investigated. The aim of the system is to effectively enhance the energy dissipation mechanism utilizing vertical motions of the girder induced by UPSS bearings, in addition to the existing horizontal energy dissipation capabilities. The effectiveness of the system in reducing the seismic response of the bridge and validity of the assumed optimal parameter settings for the most effective response control is successfully shown by numerical dynamic response analysis.

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 The Isolation Seismic Controlled Slide System(so to call ICSS)is a newly proposed control seismic for multi-span continuous girder bridges with slide using slide bearings, isolation bearings and seismic dampers. Applying this system, the bridge will be isolated so that the indeterminate force on bearings is gradually reduced due to temperature change. In addition, the seismic behavior will be controlled by isolation bearings and seismic dampers installed to a few pier. In this paper, dynamic analysis is performed for the purpose of identification of the roles for each device during earthquakes on an 18-span continuous steel bridge with 1,200m length. As a result, it was shown that the proposed system had sufficient damping ability and a stable behavior for any kinds of earthquake and input directions.

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 This paper presents a retrofitting procedure of a five-span girder bridge with nonlinear viscous dampers installed to the abutments. The study focuses on providing required damping ratio by the nonlinear viscous dampers for the desired structural responses of existing bridge. The nonlinear viscous damper parameters are figured out iteratively by the simplified single degree-of-freedom (SDOF) system possessing the fundamental characteristics of the bridge including natural period and stiffness. This iterative solution is also compared with the energy equivalent method. In addition the usage of effective weight of the bridge structure has been indicated as sufficient for obtaining damper coefficient. The dynamic analysis results have confirmed that iterative method using SDOF system is effective in terms of the reduction of structural responses under severe earthquake waves.

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 In this paper, the energy absorption performance of steel bellows as one of the energy absorption connector devices is examined for piers and pier foundations by means of non-linear time-history analyses. The effectiveness of the steel bellows on seismic force reduction is verified using a three-span girder bridge model supported on lead lubber bearings. By using the steel bellows for level 1 and level 2 earthquake, it can be expected that the steel bellows becomes as one of seismic control devices of substructure.

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 The objective of this study is to examine experimentally and analytically the damage progress of steel truss structures in cyclic loadings. The adequacy of a numerical model developed in the past study for analyzing truss structures under cyclic or dynamic loadings is examined in view of the test results of model truss structures. Seven steel truss specimens whose panel points are rigidly connected through gusset plates by high-tension bolts were tested under constant vertical loads and cyclically increasing horizontal loads. Two truss models equipped with buckling restrained braces as diagonal members were tested. Moreover, elastic-plastic large displacement analysis is executed with appropriate modeling of test truss structures and with initial lateral loads simulating initial imperfections. In many cases, good correlation between test and analysis is observed up to the points where local bolt hole damages appear near the lower panel points of test truss structures. In addition an analytical model that can examine the up-lift effect of a base plate on the hinge-support has been proposed to improve the analytical modeling.

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 This paper presents a result of a series of general investigations into the seismic upgrading of steel bridge structures. To this end, one of the most efficient ways is found to install energy dissipation devices in bridges, such as buckling-restrained braces (BRBs). An idea of installing BRBs in existing bridges is to wrap existing brace members by a sort of buckling restraining members so that the overall buckling of the braces would not occur. In this paper five test specimens of truss structures with and without BRBs in the diagonal members are tested under monotonic and cyclic loadings, and the seismic upgrading due to BRBs is verified.

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 This article describes seismic response control design using shear panel dampers for a network arch bridge. Three-dimensional non-linear dynamic time history analyses were carried out considering site-specific earthquake ground motions, to examine the correlation between shear panel damper arrangements and seismic response reductions. Different effects on seismic response reduction were significantly confirmed by the shear panel damper arrangements, and also compared between two arch bridges with different natural periods.

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 The collapse of unreinforced masonry structures, which are widely distributed around the earthquake prone regions of the world, is one of the greatest causes of death in major earthquake disasters. This paper presents an innovative retrofitting method for masonry structures, which uses bamboo band arranged in a mesh fashion and embedded in a mortar overlay. In order to evaluate the effectiveness of the proposed retrofitting technique, shake table tests were conducted using retrofitted and non-retrofitted 1/4 scaled masonry houses with sinusoidal ground motion inputs. Based on the experimental results, the retrofitted specimen exhibited good seismic performance withstanding over twice larger input energy than what non-retrofitted specimen could do.

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 It is generally thought that the underground is safer than the ground, because the acceleration amplitudes of earthquake motions tend to be smaller in the underground. However, it is considered that the seismic safety of structures will be largely affected by the mutual effects between ground structures and underground structures during earthquakes. Then, we made 3-D dynamic analyses in regard to a coupled subway - underground shopping arcade - high building system in order to evaluate the infulences of shear wave velocity on the mutual effects between high buildings and underground shopping arcade. As a result, it is considered that the displacement responses of structures and the dynamic stresses within suructures tend to increase as the shear wave velocity of ground becomes slower. In order to realize earthquake disaster prevention in urban area, it is necessary to take a dynamic interaction among the adjacent structures.

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 With the advanced use of underground space, plans to fully connect underground structures and high-rise buildings constructed under a relaxation of floor space index in compliance with the City Planning Act have been adopted in large cities. Mutual effects among underground structures, connected buildings and surrounding soil during earthquakes and the effectiveness of seismically independent systems had not yet been fully explained. In this study, earthquake behaviors which are affected by the sizes of buildings and changes in ground characteristics were analyzed for their influence on surrounding soil and underground structures using 2-D dynamic analysis methods. The study found that seismic response in the basement of high buildings is inhibited as their mass and stiffness become larger and the relative displacement with the connected adjacent underground structure increases. In addition, from the assessment of propagation effects of input earthquake ground motion, it was also indicated that the relative displacement tends to be small when buildings work to prevent the propagation of seismic waves, while it becomes lager in the opposite case.

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 This study investigates the necessity of considering different soil resistance against pipeline relative movement in upward and downward directions. In this way, results of FEM analyses are verified by experimental tests on a segmented ductile iron pipeline with 93mm diameter and 15m length installed at a 60cm depth from the ground surface in the moderate dense sand backfill condition. Fault movement, totally 35cm, has three same steps occurring in reverse way and intersection angle of 60 degrees with the pipe. This study demonstrates how assuming same resistance for soil against both upward and downward relative movements of pipeline, as suggested in JGA guideline, eventuates in imprecise FEM models.

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 This study is focusing on a non-uniformity coefficient of ground in the earthquake-resistant of a water pipeline. A lot of earthquake damage occurs at high non-uniformity ground. Therefore it is necessary to consider non-uniformity at the earthquake-resistant of the underground pipeline. By using a microtopography classification, non-uniformity coefficient in the boundary in the microtopography is studied. As a result, earthquake damage rate of underground pipeline at the boundary of the microtopography tends to be high. Therefore, the non-uniformity at the boundary can be obtained from a kind of microtopography and the boundary condition.

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 Many water pipelines were damaged in Great East-Japan Earthquake. Especially many damages were observed at the buried expansion joints used in large diameter water main lines, so that the water supply suspension was largely developed during several weeks. In this study, based on the site observation of damaged joints, the damage mechanism of buried expansion joints were investigated from the seismic response analysis.

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 Response displacement method is used in seismic designing of underground structures. In both axial deformation and rotational deformation, special solutions of differential equation which are calculated by cyclic boundary, are available so as to be simple calculation. This report proposes conducts of boundary conditions of bending equation of beam on elastic springs and non-linear calculation method using bi-linear model which is applied to materials of beam and soil spring. Calculation with sinusoidal regular wave and bi-linear characteristics is useful for improvement of response displacement method. This improvement is applied for estimation of superannuated underground structures.

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 Large-scale and three-dimensional seismic structure response analysis is carried out in order to examine the improvement of seismic capacity of a ramp tunnel by implementing a construction joint. It is shown that the placement of the joint near geological interface, where the tunnel response is concentrated, is effective in reducing stress caused by ground motion which is given to the longitudinal or transverse direction of the input ground motion. It is also shown that water leakage may occur due to large displacement of the joint. The use of the three-dimensional seismic structure response analysis is inevitable for the sheer evaluation of the effects of the construction joint as well as for the determination of its design parameters.

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 Quasi non-linear 3D FEM earthquake response analysises with level-2 earthquake are conducted for a ramp tunnel structure of Tokyo metropolitan express way central circular line the Yamate tunnel. Large-scale numerical computation with solid elements is highly required for examination of seismic response of large tunnel in case of level-2 earthquake. The results are obtained as follows: i) In level-2 earthquake, stress concentration in ramp tunnel becomes great near geological interface between two layers of high impedance contrast. ii) The response is not obtained as a superposition of two-dimensional responses which is an assumption in conventional design methods because the distribution of displacements in the direction of tunnel axis at cross-section of ramp tunnel structure near geological interface does not linearly distribute. iii) Evaluation of stress in addition to section force is desirable for the correct evaluation of the three-dimensional response of tunnel structure.

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 In railway seismic design of cut and cover tunnel, the static analytical method called 'Seismic deformation method', is generally used. This method, however, has a problem on accracy of calculation of coefficients of interaction springs. On the other hand, analysis methods used the FEM models were also developed by some researchers. We can calculate responses of cut and cover tunnels by using these methods more accurately. In this paper, we consider about the precision of the static analytical method using FEM model called 'Ground response acceleration method' by comparing the responses with ones obtained from the dynamic analyses.

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 This study analyzes three-dimensional seismic response for a ramp tunnel of the Yamate Tunnel, which consists of divergence and confluence parts, using a detailed model. Quantitative evaluation is made for displacement, stress and section force, when the tunnel is subjected to a level 2 earthquake. The major findings are as follows: 1) seismic responses is three-dimensional, rather than two-dimensional as assumed for standard seismic design codes; 2)section forces change considerably at the connection of the rump tunnel with the main tunnel. Based on these findings, it is suggested that for a large-scale tunnel structure with complicated configuration, a three-dimensional analysis using a detailed model could be used for the purpose of seismic design.

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 In the seismic design of urban tunnels in the longitudinal direction, a concept, in which axial strain can be reduced by longituginal joints, is generally adopted. However, spring constants for axial joints, determined by back calculation using the numerical results obtained from computer simulations or earthquake observations, is much greater than that calculated simply from a structural model of uurban tunnels in the longitudinal direction. In this paper, therefore, the authors propose a new design concept, in which cracks come up in tunnel lining and the tensile stiffness of tunnel lining is reduced. Then, this paper proposes a method to control a stress-strain relationship of reinforced concrete lining based on a response displacement method, using the amount of reinforced steel as a parameter.

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 Thin structures of the arch dams are influenced by the interaction of foundational rock and reservoir. In this research, transverse joints have been confirmed to open and slip. In each dam site, a dam body shape has wide variety shape, however that dam body shape effect on static behavior has not been clarified. In this paper, an analytical model considering the nonlinear characteristics of the transverse joints is built, and a symmetric and asymmetric model is modeled as the three dimensional models which have a dam body - foundational rock - reservoir system. In order to find out a vibration characteristics and resistance mechanism, each model is analyzed by the eigenvalue analysis and static behavior analysis.

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 To evaluate present dynamic properties of two aged large arch dams, the ambient vibration has been continuously measured for more than four years. These measuring tests results are employed for calibrating the earthquake response analysis models (FEM models) to evaluate the seismic safety of each dam, as well as for collecting fundamental data about vibration test-based structural monitoring. To obtain the present dynamic properties, two kinds of ambient vibration test are conducted. One is the high-density vibration array test to obtain the mode shapes of each dam. The other is long-term continuous vibration measuring test to evaluate the seasonal changes in the natural frequencies. In this paper, we show the results on identification of the some lower mode shapes, and seasonal changes in the natural frequencies due to reservoir water level and temperature. And we show the comparisons between the results from the present ambient vibration test and past forced vibration test just after the completion, and also show the comparisons between the natural frequency estimated from the ambient vibration records and the one estimated from the recent earthquake observation records.

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 Dynamic cracking analysis of concrete gravity dam has been carried out during large-scale earthquake, considering the progressive failure of jointed rock foundation. Firstly, in order to take into account the progressive failure of rock foundation, the constitutive law of jointed rock is assumed and its validity is evaluated by simulation analysis based on the past experimental model. Finally, dynamic cracking analysis of 100-m high dam model is performed, using the previously proposed approach with tangent stiffness-proportional damping to express the propagation behavior of crack and the constitutive law of jointed rock. The crack propagation behavior of dam body and the progressive failure of jointed rock foundation are investigated.

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 In this paper, we conducted a model test in 1g gravitation field and numerical analysis about seismic behavior of proposed gravity-type pier for deepwater quay wall. The performance of proposed pier is compared with that of conventional type. This proposed pier has the hybrid type structure, in which a superstructure to a substructure with steel pipe piles on base mound, it resists an inertial force and earth pressure during earthquakes by its self-weight. From results, the seismic stability of this proposed pier is confirmed, and seismic behavior of steel pipe piles can be simulated by effective stress analysis FLIP.

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 Recently the dual anchored sheet pile wall method has been developed to increase a front water depth and seismic resistance of existing quay walls by providing an additional anchor in the lower level of them to reduce a flexural moment of the sheet piles and a tension of the anchors. The existing technical information is not enough to evaluate the seismic behavior and the retrofit of the quay walls with anchors at two different levels. Therefore the experiments with a scale model set on the vibration table of the centrifugal apparatus as well as two dimensional effective stress analyses have been mobilized to investigate the seismic retrofit of the dual anchored sheet pile wall. The experiments and analyses demonstrate the increase the earthquake resistance of quay walls, because they showed the additional anchor can reduce the stress of the sheet walls to one half.

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 This study focuses on the residential consciousness on water use in the background of disaster reconstruction of water supply system in Banda Aceh, Indonesia after the 2004 Indian Ocean earthquake and tsunami. Itwas turned out that half of residents started usingwater supply system after the earthquake and the water supply system user satisfies water quality rather than the domestic water user does. The satisfaction on water supply stability is not obtained well though there is a problem in resident's manner. Finally, the disaster countermeasure to the area where earthquake and tsunami are high potential and where the water supply system is not developed yet were discussed.

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 The Great East Japan earthquake disaster caused water outage to 2. 25 million customers in all the eastern part of Japan. It was so-called "wide-area earthquake disaster". Japanwater supply authorities have improved disaster assistant system after the lessons learned from the Kobe earthquake. This study focuses on the emergency response capacity on water delivery in such a wide-area earthquake disaster reviewing the activity in assisting and assisted municipalities during the latest earthquake. The total of 355 water trucks dispatched is thought to be the maximum from the availablemunicipalities. It is turned out that the objective amount of 3 litters per person by the water delivery cannot be reached in the wide-area earthquake disaster.

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 This study proposes a new system strength index by using the topological index based on graph theory and clarifies its applicability to the real water pipeline network. Moreover, this study analyzes the system strength of water supply system under the seismic intensity level with regard of integrated system and prior-independent systems and clarifies that the integration of water pipeline network does not always improve topological strength of the system.

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 This study estimated the damage ratios of wooden houses and water distribution pipes in Tokyo, Kanagawa, Saitama, and Chiba prefectures after the scenario Tokyo Metropolitan earthquake. Since the damage ratios were evaluated by common fragility functions, the amount of damage can be compared seamlessly for the areas around Tokyo Metropolis. This study also considers the correlations between the damage ratios of wooden houses and water distribution pipes with respect to the postal address areas (cho-cho-moku) along the Tokyo Bay. The areas associated with higher damage ratios of wooden houses and water pipes were detected and the delay of restoration work is anticipated in these areas.

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 The telecommunication conduits are needed to protect underground cables from damages due to earthquakes.However, the seismic capacity is being degraded due to the superannuated conduits that were constructed during the high-growth economic period.To sustain the reliability of the conduits efficiently through maintenance is the current challenge.
 In this paper, we have evaluated to determine whether the seismic capacity can be improved by reinforcing inside tube wall of conduit with PVC lining by grasping as well as analyzing the damages of the telecommunication conduit due to the Chuetsu Offshore Earthquake in Niigata Prefecture through field study and using seismic deformation method.
 As the result, it was confirmed that the enhancement of the seismic capacity is indeed possible by applying PVC lining to the superannuated conduits.

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 The purpose of this research is to build the model of the effective operation of the relief goods in the disaster. To achieve the purpose, we analyzed the real data of the needs and supply of the relief goods distributed in Sendai-city during the 2011 off the Pacific coast of Tohoku earthquake disaster. Based on the results, it turned out that there was a difference between needs and supply at timing, and that the kinds and the amount of supply were not filled to proper amount of needs.

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 Right after the 2011 off the Pacific coast of Tohoku earthquake, the railway system in Tokyo metropolitan area completely shut down so that a large number of people had difficulty in moving. So far, many expertise in disaster prevention have proposed that such people should keep staying same place where they encountered big earthquake for their safety. However, it was observed that after the earthquake a lot of people tried to go home on foot even though the trip distance was quite long.
 In order to revise the previous disaster prevention plan, it is significant to clarify the reason why people tried to move and to verify the result of the trial. Therefore, this study analyzes the behavior taken by the people having the difficulty in moving after the earthquake.
 Web based questionnaire survey was conducted to collect data. Respondents of the survey were limited to the people who had difficulty in going home on that day.
 The discrete choice model regarding move/stay decision model and also success/failure model were estimated using the survey data. As a result of parameter estimation of the stay/move decision model, the decision is influenced by some factors such as distance to his/her home, and unsuccess in confirming the safety of his/her family. Moreover, as a result of parameter estimation of the success/failure model, the result is influenced by some factors such as distance to his/her home, age, gender, and difficulty in obtaining evacuation route information.

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 An LED display system of earthquake ground motions is developed as a teaching material for disaster prevention. The time history of the seismic motions can be simultaneously demonstrated at many sites by illuminating computer-controlled LED embedded in the relief map. The LEDs are located at the observation sites of K-NET on the map, which is employed by NIED (National Research Institute for Earth Science and Disaster Prevention), and any earthquake motions downloaded from the website can be applied.
 Better educational effect and more realistic expression for the understanding of earthquake ground motions can be expected by using this system compared with by using the computer graphics. Moreover, it is helpful to understand the relation between the geological features and the ground motions since the relief map is used.

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 After disaster occurs, various organizations usually conduct investigations in the affected area for understanding disaster situation. In order to avoid excessive burden to the affected area, cooperation and information sharing among different organizations are essential. Collaboration of various academic fields is much more necessary in case of extremely wide-area disaster because existing academic frameworks may not give solutions to new social problems. In this papers, activities of 86 academic societies after the 2011 off the Pacific coast of Tohoku Earthquake were compared from the viewpoints of system, collaboration, publication of remmomendation and dispatch of specialists to the affected area.

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 In Japan, several big earthquakes are expected to occur in the near future. A lot of structural damages due to these earthquakes will cause enormous needs for building damage assessment. In this paper, a system for supporting administrative staffs was designed and photo management system (PhotoMas) was developed in Miyagi prefecture during the 2011 off the Pacific coast of Tohoku earthquake. The system for management some photos of damaged houses and some database which managed local governmant was developed based on Excel VBA. This system makes easier to search photos which are taken by inspector in damaged area, and the system can visually confirm the percentage of completion of building damage assessment.

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 In the 2011 off the Pacific coast of Tohoku earthquake, we could observe concentration of news on damage and disaster response activity of specific municipalities and the high emphasis on the nuclear power plant accident and so on. The concentration of TV news caused the concentration of support such as releaf goods and donations to the specific area. This problem was repeated from the past disaster. The purpose of this research is to analyze the cities where was repeatedly reported by TV news during the emergency period on the 2011 off the pacific coast of tohoku earthquake disaster. This research defined the ratio of reported-city to show the comparison of the level of repeatedly reported cities. The results shows the big difference of reported times among the cities with same number of casualities.

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 Law on promotion of renovation for earthquake-resistant structures was revised in 2006. Since then administrative agencies have been promoting seismic diagnosis and retrofit of houses. But citizens living in densely built-up areas cannot rebuild their houses because of their economic reasons and Building Standards Act regulations. Therefore, we conducted questionnaire surveys of construction companies located in Ishikawa Prefecture and citizens living in Kanazawa City. The results of surveys show that many construction companies are not in favor of simple method of seismic retrofit, and that width of roads hardly influence the citizens' consciousness to renovation for earthquake-resistant structures.

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