Axial soil spring between the pipe and ground is treated as the Coulomb's friction law in the seismic response analysis of buried pipeline, for water and gas supply, etc. In order to investigate an axial soil spring considering the velocity dependency of soil friction, the pipe pulling-out test using the shaking table was carried out in addition to our previous tests. Not only the pipe moving velocity but also soil and install depth were dealt as the parameter. In the slow-moving cases, the friction coefficient was 0.4 to 0.6 regardless of the soil and pipe material. The positive velocity-dependency appeared in the cases of cohesive soil with low water content, whose maximum shear stress increased 1.2 to 1.4 times comparing to that of the slow-moving cases. The cases of sandy soil with low water content did not show the positive velocity-dependency.

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 In small-scale city, where populations are aging and decreasing, not only structural measure but also non-structural measure of water supply and sewer system against natural disaster are useful. To plan the effective non-structural measure, consciousness of local residents are important. This study proposes a combination method of structural and non-structural measure through a case study in Wajima district of Wajima City, by a questionnaire investigation to the local residence. Degree of recognition of low earthquake-resistant of water supply facilities was very low and storage of water was few. Although average acceptable days of water supply cutoff were 3 days, willingnesses to pay (WTP) for structural measure of water supply. The public information of water storage is important. Comprehension of limitation of water usage during the damaging period of sewer system was relatively high, and average acceptable days of portable toilet usage were 5.6 days. Willingnesses to pay (WTP) for structural measure of sewer system was 190 yen/month, and WTP for portable toilet was 66 yen/once. Storage of portable toilet by government was estimated to be useful for limitation of water usage.

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 Though human losses due to collapses of buildings and damages related to roads and river facilities were observed during the 2015 Nepal Gorkha Earthquake, the functions of many gabion structures were found to be maintained because of their high flexibility against earthquake in mountainous areas. In order to evaluate the earthquake resistance of gabion structures, the authors conducted field surveys along the Araniko Highway where a lot of slope-related disasters occurred during the earthquake. It was found that due to the advantage of low cost and easy construction, as well as the readily available construction materials, gabion structures were widely used in roads, rivers and erosion control works in Nepal. Based on the surveys, we analyzed the current status of gabion applications and structural features of gabion structures, and suggested issues and specific methods for the design and construction of earthquake resistant gabion walls.

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 Earthquake-induced landslides on gentle slopes sometimes cause tremendous damage to human society. They are normally not designated as a steep slope area in danger of failure because of their gentle slopes. Characteristics of such a landslide have been studied by many researchers. However, failure mechanism, especially under dynamic condition, is fully unknown. Based on the field investigation and laboratory test results, the slope of Hanoki-daira in Fukushima Pref., where this type of landslide occurred in the 2011 Tohoku Earthquake, is modeled as one-dimensional FEM model to elucidate the failure mechanism. As a result, it indicates that the balance of shear stress before seismic motion acting and shear strength at slip surface is important for earthquake-induced landslides on gentle slopes.

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 Masonry retaining walls are very fragile structures against earthquakes and a great number of damages have been reported. We should elucidate a failure mechanism and make appropriate safety assessments and countermeasures.
 The objective of this study is to establish the analytical methodology for the seismic evaluation of the masonry retaining wall. We conducted some numerical simulations based on a coupled the DEM (Distinct Element Method) and the SPH (Smoothed Particle Hydrodynamics) analysis for the pull-out experiment, and improved the program code as well as the analytical model by focusing on the inconsistent between the analytical and the experimental results. The calculated residual shape of the masonries was a good agreement with the experimental one, and some points to be improved were classified.

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 The earthquake resistance of transmission tower has been often discussed from the viewpoint of reinforcing the foundation of steel tower, but there are still few studies considering the damping characteristics of the tower. This paper focuses on the tuned mass damper (TMD) which has been adopted for seismic reinforcement of bridges in recent years. The purpose of this research is to improve the seismic performance of steel tower by giving the high damping to the tower. We construct a single tower model considering the influence of transmission line, and then simulate the vibration characteristics and seismic behavior of the tower by the eigenvalue analysis and the dynamic response analysis. The results show that the transmission tower with TMD can reduce its own response effectively and drastically. This study concludes that the collapse of steel tower can be avoided by using the optimum damper in the design of the transmission tower.

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 As the limits of public assistance become clear in past large-scale disasters, it is important to utilize soft power by cooperation, and improvement of regional cooperation power is an indispensable task for future large-scale earthquake disasters is there. In this research, we will conduct a basic assessment of the potential for assistance, such as the extent to which the region has the ability to support each other, assuming possible large-scale earthquake disasters. Furthermore, from the utilization of the National Health Insurance Database, which is the medical big data, we grasp the actual state of regional cooperation by grasping important considering people in case of disasters with severe illness by town letter unit. As a result of the analysis, we were able to grasp the details of the town letters of the number of people who took care of, and clarified how much they reside in areas with mutual assistance potential.

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 In the Kumamoto earthquake and the Great East Japan Earthquake, in addition to public facilities such as hospitals, water storage tanks such as apartment houses were damaged more than the sloshing phenomenon caused by long-period seismic motion and caused an influence on the lives of citizens . In order to prepare for the large earthquakes occurring in the near future and the Inland earthquake etc., it is necessary to grasp the dynamic behavior of the water storage tank to reduce the sloshing phenomenon in order to secure the lifeline at the time of earthquake disaster. In a previous study by the authors, the panel type vibration damping device demonstrated the effect of reducing sloshing on the water tank. However, the workability of the vibration damping device was poor, and it took a lot of time and effort in construction. Therefore, in this research, we improved the workability and devised a method to assemble the panel into a figure 8 shape. Experimental experiments were carried out in an actual water tank to verify the workability of this vibration damping device and the effect of reducing sloshing. As a result, it was found that the workability is remarkably superior to that of the conventional vibration damping device, and also the wave height reduction effect of the same level as the wave height reduction rate is exhibited as in the conventional case.

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 More than one million tonnes of tires are discarded in Japan annually. Stockpiling of scrap tires in landfills may cause serious environmental and health problems. Reusing or recycling of waste tires can significantly contribute to reduction of waste product's destructive environmental footprint. Scrap Tire Derived Materials (STDM) have interesting physical and mechanical properties that make them suitable for civil engineering applications like rubberized concrete productions, slopes protection and stabilization, light weight backfill for retaining walls and subbase material for foundation of structures. STDM and sand-STDM mixture are largely being used and investigated in literature. However high compressibility and low elastic modulus of tire chips and sand and STDM mixture could result in high differential settlement and inadequate bearing capacity of foundation. In order to solve the aforementioned issues, Gravel-Tire Chips Mixture (GTCM) as an alternative geomaterial has been introduced by Hazarika et al. (2016). However, geotechnical structures reinforced with GTCM might be subjected to dynamic, repetitive or impact loads such as earthquake, blast, traffic loads. So design, evaluation and maintenance of such structures needs an investigating of dynamic behavior such as shear modulus and damping ratio and liquefaction potential of Gravel Tire Chips Mixture. A series of consolidated-undrained cyclic triaxial tests were performed on gravel and GTCM specimens to examine the influence of gravel fraction and effective confining pressure on their dynamic behavior as well as liquefaction resistance. Test Results have shown that initial shear modulus and liquefaction resistance are highly influenced by gravel fraction in GTCM. Furthermore, GTCM samples possesses a higher liquefaction resistance at low confining pressure. Samples exhibits GTCM and tire chips like behavior with high deformability as tire chips inclusion increases in mixture. Additionally, a new empirical expression is presented relating the maximum and minimum void ratio to the gravel fraction in GTCM specimens.

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 In large metropolitan areas, there are many cases where large buildings are built adjacent to a railway viaduct. These buildings are quite massive compared to the size and weight of a railway viaduct. In an event of an earthquake, response of such buildings can have an adverse effect on the railway viaducts; considerations for such are too serious to be ignored. In this paper, dynamic interaction between a railway viaduct and adjacent buildings based on numerical analysis is investigated. Results indicate that the effective input motion to the viaduct is reduced considerably due to the presence of rigid foundations of adjacent buildings. However, when the rocking mode of the adjacent building dominates, the effective input motion tend to increase.

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 The three dimensional coordinate values before and after the earthquakes could be measured by the aerial-photogrammetry using the common pricking points before and after the earthquakes, by proposing the calculate method of the coordinate values of the pricking points before the earthquakes. The aerial-triangulations were conducted. As the result, the locational accuracy of the proposed pricking points before the earthquakes could be verified. The manhole variation amount was conducted at the control point vicinity that the variation amount was known, in order to verify the manhole variation amount by proposed method. As the result, it was confirmed that the conducted variation amount was almost the same as the variation amount of the control point. The relative displacement, initial slope and axis strain between the contiguous manholes could be calculated, by measuring the three dimensional coordinate values of manhole before and after the earthquakes continuously. These were classified into “Damage” of the NTT pipeline damage surveying and “No damage” of that, in order to analyze the relationship with pipeline damage.

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 In this study, microtremor observation was carried out for local governments where the natural disasters caused by multiple origins such as earthquake shaking and tsunami were worried, and the sedimentary structure of the ground was estimated by the predominant period and the corresponding peak amplitude of microtremor H/V spectral ratio. In addition, we proposed the risk evaluation method of ground shaking hazard and illustrated contour maps for spatial distribution of the evaluated risk. The validity of the risk evaluation scale was verified to compare with integral value of H/V spectral ratio.

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 In the technical standards for port and harbours, static force-based method that does not take the effect of deformation of quay walls by earthquake into consideration is applied as a general earthquake resistant design method against the Level-one earthquake ground motion for sheet pile quay walls. It is difficult to evaluate the performance of the quay walls by earthquake precisely by the method. Previous study was undertaken in order to establish the simplified earthquake resistant design method based on the frame analysis for the quay walls. Although the method fairly reproduced the performance of the quay walls, section forces of anchor pile could not be evaluated. This study aims at improving the simplified design method by modifying the lateral soil resistance in front of the anchor pile. Two-dimensional earthquake response analyses were conducted in order to discuss the applicability of the modified simple design method.

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 Diagonal compression tests of normal masonry walls made of rectangular bricks and irregular masonry walls made of interlocking bicks were conducted, and failure mechanism and strength increment effect by using interlocking bricks were investigated. It was found that the masonry walls with interlocking bricks have less maximum strength compared to the masonry walls with rectangular bricks, and the strength increment effect could not be seen. Then the finite element analysis was conducted to understand this mechanism. It was found that stress consentration occurs at the interlocking part in the interlocking masonry walls, this stress concentration causes the failure inside the bricks at the interlocking part.

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 It has been pointed out that the effect of partially saturated surface layer (above the groundwater table) cannot be ignored when ground is liquefied. In this research, a series of centrifuge tests was made to clarify the effect of pore water inflow into a partially saturated surface layer during liquefaction. The pore water inflow was measured in terms of the increases in the degree of saturation and excess pore water pressure. The degree of saturation was measured by using an electrical soil moisture sensor. Four tests were carried out by changing groundwater level and pore fluid type (water or viscous fluid). The extent of the expansion of saturated area during and after shaking was different among the cases. Comparison between liquefied and non-liquefied cases indicated that there were obvious differences: a part of the unsaturated layer changed into a saturated one due to the seepage from an originally saturated layer located below. In addition to the tests, three phase numerical analyses which take the effect of pore air pressure into consideration were performed for the centrifuge tests. The simulation well captured the change of the degree of saturation, the response of excess pore water and air pressures.

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 The 2011 off the Pacific coast of Tohoku Earthquake Tsunami devastated not only houses but also sewer systems. It is important to discuss the risk of tsunami damage to sewer systems and to make business continuity plan (BCP) in advance. The purpose of this study is to discuss insufficiency of the BCP and possibility of unassumed tsunami damage in Wajima City. Wajima is facing to the Sea of Japan and assumed possible maximum tsunami inundation by the north offshore Noto earthquake model. The overground modelling uses elevation and road information data, and the underground modelling uses sewer system data, such as size and location of manholes, and length, depth, and gradient of pipes. The integrated overground-underground inundation model simulates the tsunami floods not only on the ground but also into the sewer. The detail analysis indicates not a few pipes were filled by tsunami inundation and water level in manhole became high. High water level of manhole compresses the air and increases the possibility of manhole cover detachment.

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 The objective of this study is to examine the effect of uplift of spread foundations on seismic response of bridges with viscous dampers used as seismic response control dampers based on the results of seismic response analysis. It is found that when damping force of viscous dampers, which are connected to abutments, becomes larger, the maximum value of curvature that occurs in plastic hinges of bridge piers becomes smaller, even if uplift occurs. It is also found that uplift reduces curvature when curvature becomes significantly larger than the yield curvature of the plastic hinges if uplift doesn't occur. On the other hand, it is found that when damping force of viscous dampers, which are connected to bridge piers, becomes larger than a prescribed value, maximum value of curvature, which occurs in plastic hinges of bridge piers, becomes larger even if uplift occurs.

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 In this study, cyclic analyses of variable pipe cross-section steel piers are conducted aiming to propose an earthquake resistant design method. If buckling occurs at pier base, steel piers with variable pipe sections have almost the same the seismic performance as those with uniform pipe sections. Based on analytical results by employing a modified two-surface model, a conditional expression for avoiding buckling in the part of variable sections is derived. The analytical results show that the steel piers of variable pipe sections as good as that of uniform pipe sections can be designed easily by using the proposed design method.

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 The evaluation of earthquake motion is basic problem in the earthquake engineering. In this study, the kernel density estimation and the Gaussian mixture model were applied to the 99-dimensional feature vector representing the temporal characteristics of a strong motion on the basis of its Husid plot. For numerical example, the acceleration records observed from the 2011 Off the Pacific Coast of Tohoku Earthquake were used. The shape of envelopes that were calculated by proposed method were similar to the earthquake motion. Next, the travel time estimated using the acceleration record and the proposed method were compared with reference to the source process. The average and standard deviation of element model from the Gaussian mixture model were found to reflect the source process. As another analysis, the kernel density estimation and the Gaussian mixture model were applied to describe evolutionary power spectrum. The average of element model from the Gaussian mixture model indicated the capability to find the surface wave.

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 This study discusses the mechanical characteristics of high damping rubber bearings (HDRBs) by dynamic loading tests under the low temperature environment. Fundamental cyclic loading tests at different temperatures are conducted using 2 types of HDRBs (HDR-S and HDReX) and a natural rubber bearing (NR). In these tests, 175% shear strain of rubber thickness are given by loading facility in cold room. Equivalent stiffness of all specimens increase under low temperature and its ratio depends on type of rubber. Specially equivalent stiffness of HDR-S is significantly larger than other types because of its material characteristic. Internal temperatures of rubber bearings have linear relationship with energy loss. Gradients of the linear functions also depend on rubber type and ambient temperature. In cyclic loading tests under allowable design displacement (250%), the rate of change of the equivalent stiffness and energy loss of HDR-S significantly increase specially in −30°C. Finally, all specimens do not break under cyclic loading test of 120% allowable design displacement under any temperature cases.

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 Pile-supported RC buildings were pulled up and toppled by the 2011 Off the Pacific Coast of Tohoku Earthquake Tsunami. There were some buildings around the target building and the ground was soft, so the complex tsunami flow between buildings and the soil condition influenced by the earthquake and the tsunami have to be considered to found out the damage mechanism. In this study, we find out the soil condition at that time with FEM analysis using tsunami horizontal force getting by three dimensional tsunami analysis. As a result, it was shown that liquefaction was occurred under the building when the biggest tsunami horizontal force act upon the building and piles were broken. It was also shown that at that time the tsunami made the rigidity of the surface soil higher than that of dipper area.

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 This study focuses on space dilatation by using MLT method as a countermeasure of liquefaction. Relative density of sand layer is increased by space dilatation by using MLT method. First, increase of the relative density of sand layer was theoretically estimated by space dilatation theory. Then laboratory tests were conducted by a model auger screw and sand box. The results of laboratory tests showed good agreement with our estimation and increase of relative density of sand layer was verified. A field test was also conducted. The increase of relative density was not clear in clay layers but clear in sand layers a little.

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 Couple of rubber bearing supports on highway bridges were damaged by 2011 Tohoku Pacific Off- shore Earthquake and 2016 Kumamoto Earthquake in Japan. Even though the seismic design method for the rubber bearing support has been developed by a lot of experimental and analytical studies since 1995 Kobe Earthquake in Japan, the shear properties of the rubber bearing support with a tensile axial force has not been identified due to lack of related studies. In our past study, in order to investigate the shear properties of the rubber bearing supports (RB) with a tensile axial force, cyclic loading tests varied with axial forces of RB test specimens were conducted. In the tests, using 4 test specimens with same specification, 6MPa compressive stress, 0MPa, 1MPa tensile stress and 2MPa tensile stress as the axial stress were loaded on each test specimen. Here in, in order to evaluate the local internal stress of the rubber bearing supports subjected to a tensile axial force and a shear force, FE analyses considered the hyperelastic and viscoelastic properties of a rubber material were conducted. After verifying the reproducibility for the experiments by the analyses, the local stress states of the rubber bearing supports were investigated. By the analyses varied with axial forces, the stress distributions of the rubber bearing supports were investigated.

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 In this study, we analyzed the seismic behavior of multi-span suspension bridges with a center span length of 3000 m. Since the characteristic vibration periodicity of the suspension bridge differ depending on the member, multiple observation waves which greatly influence each are selected and excited in three directions at the same time. In addition, since the deformation of the suspension bridge will be estimated to be very large at the time of the earthquake, the time history response analysis considering the geometric nonlinearity and compared its behavior by the number of spans. Furthermore, since the total length is as long as 6 to 12 km, we also carried out multipoint input analysis considering the phase difference of the seismic motion, and we made comparison based on the presence or absence of phase difference.

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 Damage to highway bridges caused by the 2016 Kumamoto earthquake has occurred in a wide range and various investigations have been carried out. In this study, to be make it the basic material used for analysis on the highway bridges damaged by the earthquake, attention was paid to seismic design specifications, length of the bridges, damaged part, and measures to prevent falling bridge. Then relation between the earthquake ground motion and degree of the damage was organized and statistical analysis was carried out . As a result, it became statistically clear that multiple span bridges show higher damage rate than single span bridges, damage to bearings accounts for most of the damaged highway bridges, degree of the damage increases as stronger earthquake ground motion acted, etc.

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 In this research, the author reports problems of traditional observation methods for evacuation behavior and developed the new observation method which resolved these problems. This method was applied for an actual evacuation drill and its utilization possibilities was tested. Specifically, it is shown that how analyze the evacuation start and completed timing, the required time to evacuation and the margin for evacuation time, and the results of using these analysis methods. As a result of this research, it is confirmed that the effectiveness of the developed method as a part of feedback method for evacuation drill.

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 In the case of railway structures, there are cases where it is inevitable to construct structures on faults or in the vicinity of faults due to the alignment restrictions, and it is necessary to construct structures considering the influence of surface fault displacement. However, there are no adequate method for considering its influence. We have been conducting a study targeting rigid-frame viaducts which are widely used as railway structures and have proposed the single span viaduct with cantilever system as an effective type of viaduct against surface fault displacement. In this paper, we studied the behavior of the viaducts with different types of connection with the adjacent structures including cantilever system. In the study, we considered three types of connection which are Gerber beam type, footing integrated type without girders and cantilever type, and evaluated relative displacements at connecting part by using static nonlinear analysis. As a result, it is confirmed that the viaduct of Gerber beam type reaches a falling bridge with a slight amount of surface fault displacement and it is found that the proposed connecting type is effective.

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 In seismic performance verifications of steel pipe pile structures at port facilities, the evaluation of whether or not the calculation of the bending moment reaches full plastic moment is mainly performed by using the bilinear elasto-plastic model of M-φ characteristics. Since local buckling occurs in steel pipe piles with a large diameter-to-thickness ratio, which are used frequently due to economical design, the bending moment declines without reaching full plastic moment. On the other hand, the bending moment of steel pipe piles with a small diameter to thickness ratio slowly increase even after yielding, this effect cannot be taken into consideration in the above. Therefore, we have tried to clarify strength and deformation characteristics of steel pipe piles by three dimensional FEM analysis using shell elements, and we have proposed a verification method using ultimate curvature instead of full plastic moment. We have also confirmed that high strength steel pipe piles (570N/mm² tensile strength class) can cope with the same as conventional steel pipe piles by introducing a correction coefficient of yield stress.

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 Since the Hyogoken-Nanbu earthquake, many studies have been carried out to improve seismic performance of infrastructures. As one of them, an new type bridge pier which 4 steel pipes is connected by shear panels are proposed and developed, Ltd. Dynamic behavior and seismic performance of this structure have been clarified by the past research, and it is applied in the lamp section of Ebie JCT of the Hanshin Expressway No. 3 Kobe Line. In this structure, from the viewpoint of improving the seismic performance of the shear panel, the seismic performance of a shear panel with a longitudinal stiffener has been analytically confirmed. Experimental study on seismic performance of shear panel with stiffener has not been studied. Therefore, in this research, experimental study was conducted with the aim of clarifying the detailed performance confirmation and the mechanical behavior with stiffener including the bolted joint.

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 After a major disaster, relief supplies can't get immediately. Therefore, we suggest the self-help and mutual assistance using the regional food just after the disaster. Regional food is food of the household during daily life and food in the retail store, but not stockpiling of food for disaster.
 Questionnaire survey were conducted in Kanazawa City, Ishikawa Prefecture, and in Adachi Ward, Tokyo. We surveyed about the food that general family and the student living alone have. Moreover, we carried out the research in the convenience store, and clarified the quantity of the product which are in the store. From these results, we examine utilize the regional food in ordinary times as a food at the time of disaster.

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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, we proposed a new spring arrangement model in the refined DEM with which the friction coefficient and rocking angle are accurately produced. The validity of the new spring arrangement model was confirmed by comparing the results with theoretical solutions. Next, the dynamic behavior of a plain concrete pier during the shaking table was simulated. By improving the numerical model in addition to the spring arrangement model, we could improve the accuracy of horizontal dislocation and failure behavior. We could solve the problem of underestimating rotational angle, but the accuracy of rotational angle is insufficient.

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 In this research, a field experiment for tree overturning and a laboratory test for bending moment were examined to understand the limit of coastal trees against tsunamis. Focusing on the moment generated by the effect of tsunami's fluid force on the coastal trees, field-experiments were conducted on the characteristics of the limit of mechanical strength at Yaizu-Tajiri coast. In the field experiment, Japanese black pine trees were pulled down. And the pulling load and the displacement of tree were simultaneously measured. In addition, the bending moment of the tree trunk cross section was measured as a condition of trunk breaking. Based on these measured data, the mechanical strength limit of coastal tree was compared with other place data and model formulas.

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 During the 2011 Tohoku tsunami, more than half of the tsunami victims were estimated to have not started evacuation despite sufficient evacuation time and warning information being provided. Understanding how a tsunami evacuation starts is essential in order to mitigate human damage due to tsunamis. This study suggests a survey method that could enable us to satisfactorily understand the process of the start of a tsunami evacuation. We propose a monitoring method wherein at the start of a tsunami evacuation, an unmanned aerial vehicle (UAV) is released such that it shoots an aerial video during the tsunami evacuation. This was tested at the drill held in Ama-Nakanishi district, Minami-Awaji city in Hyogo prefecture. The advantages of the proposed method over existing methods (primarily, social survey) is twofold: First, there is no dependency on people's memory, and second, spatio-temporal data of every behavior can be obtained. To test this method during the evacuation drill, two steps were necessary. First, we had to receive regulatory approval for flying the UAV, and second, we had to conduct a preliminary survey to decide the shooting location considering the coverage area (the whole district) and the resolution (to identify each behavior). We found that this method enables us to understand not only every human behavior caught on the aerial video but also the interaction among the residents and the relation between their behavior and the surrounding conditions, all of which are very important to discuss the start of a tsunami evacuation.

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 Authors proposed the modeling of the steel pipe for the seismic performance verification for pile-supported wharves against the level II design ground motion. The proposed method can evaluate the load-bearing capacity and the deformation performance of the steel pipe, where local buckling occurred. In this study, we performed a reproduction analysis of the open-type wharves on vertical piles in the Port of Kobe which was damaged during the 1995 Hyogoken-Nambu earthquake with the aim of confirming the applicability of the proposed model. The results showed that the plastic hinge occurrence in the steel pipe piles and the residual deformation of the open-type wharves on vertical piles were consistent with the actual damage.

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 Repetitive strong earthquake motion acted on public works during the 2016 Kumamoto earthquakes. The purpose of this study is to examine influence of repetitive strong earthquake motion during the 2016 Kumamoto earthquake on seismic performance of highway bridges. In this study, first, nonlinear beam element model was verified based on the results from a large-scale experiment of repetitive loading on RC pier at E-defense. Strong motions repeatedly observed at the same sites during the 2016 Kumamoto earthquakes were employed for nonlinear dynamic analysis of highway bridges that were designed by Level-2 earthquake motions. As a result, number of plastic response of the RC pier was confirmed to remain under criteria of the 2012 seismic design specifications for highway bridges.

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 Based on shaking table tests or loading tests for steel superstructures, previous studies have investigated applicability of damper and brace as seismic energy absorbing devices. However, these studies have used large-scaled and therefore it is difficult to carry out parametric loading tests. On the other hand, previous studies have proposed analytical models for steel superstructures. However, some of these models are simple analytical models, and the others are highly accurate analytical models. Therefore, it is necessary to develop small-staled test and simple, accurate and practical analytical method, which can investigate applicability of damper and brace for steel superstructures.
 This study aims to develop an experimental small-scaled model of the steel superstructure that can agreed well with the large-scaled model developed in previous study. This study focuses on the reproduction of a small-scaled model, which can be capture the strength and deformation of large-scaled model. A 0.24-scaled model, which is scaled from a full-scaled structure and is 0.57 scaled of large-scaled model in the previous study, was made in this study, and its cyclic loading test was conducted. In addition, this study developes of analytical model of steel superstructure, which used fiber elements to efficiently capture the strength and deformation in the analysis.
 As a result, the developed small-scaled model was acceptable in the estimation of the large-scale test results unless the concrete deck stuffed severe damage. In addition, the developed of analytical model considering studs modeled by vertical and horizontal spring elements was agree well with the the ultimate lateral load carrying capacity and the hysteresis curve of the large-scale test results.

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 In resent years, Earthquakes and according disasters are considered as wakeup call to earthquake engineers to consider the probability of the earthquakes exceeding design limitation and the corresponding structural damage. Anti-Catastrophe have been discussed and Function Separated Bridge, using multiple energy dissipation and isolation devices, is proposed to separate the risk from damage of critical member. In this study, Incremental Dynamic Analysis and earthquake risk assessment are conducted for Function Separated Bridge. It is found that broken of SPD first and then HDR is the most probable fail scenario for the Function Separated Bridges due to all kinds of earthquakes. According to the earthquake risk assessment, the risk of Function Separated Bridges is about half of the convenient isolated bridge.

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 This work, entitled “Project for the Comprehensive Analysis and Evaluation of Offshore Fault Informatics”, was supported by the Japan Ministry of Education, Culture, Sports, Science and Technology (MEXT) through the Japan Agency for Marine-Earth Science and Technology (JAMSTEC). The purpose of this study was to verify fault modeling in the source region of the 1983 Nihonkai-Chubu earthquake, which was caused by marine faults located offshore Japan. We investigated the 1983 Nihonkai-Chubu earthquake as a more typical example of tsunami earthquakes that occur in the Sea of Japan, which have been reported by many previous studies. We constructed a new fault model using marine seismic industry data and geological and geophysical data compiled by the Offshore Fault Evaluation Group, Japan Agency for JAMSTEC. The marine seismic industry data included information from a new fault located to the north of an existing fault investigated previously. We adjusted the geometrical continuity of these faults, whereby the magnitude of the fault slip was increased. We applied the standard scaling laws based on strong ground motion for the fault parameters. The validity of the fault model was examined by comparing tsunami heights of the Japanese coastline between historical observation records and the tsunami simulation analysis, and by quantifying obtained data using scale and variance parameters referred to as Aida's K and κ. Based on the results, and by referring to geological data and aftershock location, the simulated tsunami heights using the new model approached the heights observed in historical records. This indicated the validity of the model for accurately modeling the source region. In future studies, more reasonable results are expected by considering asperities and fault parameters located in the shallow part of the source region. By considering the fault data obtained by referring to geological data and aftershock location, the explanation of the tsunami traces due to the past earthquake was shown to be effective.

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 The Yadanatheinkha bridge under construction is collapsed due to the Thabeikkyin earthquake happened on 11 November 2012 in Myanmar. Only the superstructure of the Yadanatheinkha bridge under construction is considered in this study. Static analysis of the Yadanatheinkha bridge under construction and dynamic analysis due to El Centro 1940 earthquake are carried out by numerical analysis using OpenSees software. Firstly, the king post is neglected to check the performance of the bridge structure under construction without supporting of the king post and only the weight of all structural members of the bridge truss and traveler crane are considered in the analysis. Then, the Yadanatheinkha bridge under construction with supporting of the king post is analyzed to realize the importance of the structural control of the king post for the bridge during construction stage and the weight of all structural members, traveler crane and king post are considered for the analysis. The stability of the bridge under construction is checked for both cases.

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 The 2016 Kumamoto earthquakes had caused many damages on water supply facilities. Damages of water supply facilities associated with unexpected significant ground deformation, and foundation damages of the structures that meet the new earthquake resistant standard (standard for earthquake resistant design after 1981 in Japan) were reported at water supply well areas that surrounded by rivers and located in lowland with soft clay layer and saturated sand layer. As professional engineers and researchers who design and construct water treatment and sewage plants and pipelines, the authors conducted investigation and analyzation in order to find out the relevance between the damage of water supply facilities and the ground behavior including liquefaction during the earthquake. Based on the results of this study, we analyzed the seismic damage mechanism and factors, and discussed about the earthquake-resistant measures in future for the piles and well casings inside water distribution stations in water supply well areas, which are very important for the water supply system of Kumamoto City.

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 According to the investigation report of on the pipeline damage in Great East Japan Earthquake, there are much damages not only distributing pipes but also service pipes and branch saddles. The report mentions that it is important to evaluate the seismic performance of service pipes and saddles to maintain the water supply network during a severe earthquake. The purpose of this study is to evaluate the seismic performance of a service pipe. We performed the test to figure out effects of slippage between distributing pipes and surrounding soil on a service pipe, and influence of ground strain of pipe axis direction on a service pipe. In this study, high density polyethylene (HDPE) pipes with mechanical joint were used for a service pipe. As a result, HDPE pipes and mechanical joint showed a significant earthquake resistance capability because these pipes performed well against the ground deformation.

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 An earthquake (M_j6.6) occurred in central Tottori prefecture in Japan on October 21, 2016. We investigated nonlinear soil response based on strong ground motion of K-NET, KiK-net station (NIED), local government observation station in Tottori prefecture and temporary observation station by Tottori University. In this study, we calculated a nonlinear soil response due to this earthquake using an index for easily evaluating the degree of nonlinear response. In addition, we compared the index with indicators of ground motion and subsurface structure. As a result, we grasped a characteristics of the nonlinear ground response due to this earthquake.

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 A series of 3-D FDM simulations are demonstrated for studying characteristics of near fault strong ground motions. Several strike slip rupture scenarios are generated to discuss effects of rupture propagation. Forward directivity pulses with large fault normal component are generated at the end of source fault in propagating direction in case of horizontally propagating ruptures. In the case, however, ground motions at rupture starting point on the source fault are very small. In case of vertical propagating ruptures from the bottom of faults, large fault parallel ground motions as expected in fault slip direction are generated around the source fault. In the case, ground motions on the fault line are very small. From the simulations, there exist some special cases that lead very small ground motions on the strike slip fault line as observed in several disastrous earthquakes, e.g. the 2016 Kumamoto Earthquake. Further minute study is required to explain the reason of the phenomenon completely.

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 An evaluation method for ground motion has been proposed considering the effects of constituent pulse waves. First, a triangular pulse wave model representing the skeleton of a strong motion has been proposed in order to evaluate characteristics such as amplitude, predominant period and the temporal properties. Next, a technique for time-frequency analysis taking advantage of the energy input rate (EIR) has been proposed in the light of the amplitude, the direction and the time-position of the constituent pulse waves. It has been found out that the combination of the sign and amplitude of both acceleration pulse input and structural velocity response determine the structural response. The proposed method can be used for analyzing the effect of pulse waves on amplification and damping of structural responses, and the relevance of pulse waves to impulsive load and/or resonance of structure. Five ground motion records observed during four inland crustal earthquakes in Japan have been used for numerical examples.

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 Source modeling method for strong ground motion prediction targeting intra-plate earthquake has not been established in the technical standards for civil engineering works yet. In this study, authors applied two kinds of source model that are likely to be introduced to the practical design. One is characterized source model in accordance with the latest recipe for strong-motion prediction shown by the Headquarters for Earthquake Research Promotion and the other is pseudo point-source model proposed by Yamada et al.. Results of the study showed that pseudo point-source model gives conservative earthquake ground motions compared with the characterized source model.

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 Surface ruptures were observed after the main shock of the 2016 Kumamoto earthquakes. Large velocities were also observed at the strong motion stations near the surface ruptures. Near and intermediate field terms due to the shallow slips could be responsible for the large velocities. In this study, in order to include the near and intermediate field terms in the strong motion simulation, we verified the method by Nozu (2006) to consider these terms by comparing numerical and analytic solutions. They showed good agreement when the interval of the point sources in Nozu (2006)'s method was appropriate. Then the relationship of the size of the fault plane and the permanent displacement, and the contributions of each term were examined.

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 It is important in disaster prevention planning to grasp safety and danger of coastal area against predicted future huge tsunami, and an accurate numerical simulation method is strongly desired. In practical works, tsunami simulations for tsunami propagation and run up into ground is carried out by 2D simulation, but it is pointed out that some numerical errors especially in the tsunami run up simulation, which should be treated as a 3D problem, can not be ignored. It is necessary for the 3D simulation with the current computer power to utilize a super computer, and it is almost impossible to apply directly to practical use. Therefore, in this research, we tried to model houses, building and embankments as precisely as possible within framework of the 2D simulation. Numerical results by the 2D finite difference method with different level of fidelity of structure modelling gave us quite different results especially in the tsunami arrival time.

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 Like other lifeline facilities, telecommunication conduits also suffered damages due to strong inland earthquakes, such as 1995 Great Hanshin Earthquake, 2004 Chuetsu Earthquake and 2007 Chuetsu Offshore Earthquake. In this study, damages of telecommunication conduits due to past inland earthquakes are analyzed. The relationship between telecommunication conduits and seismic intensities (peak ground acceleration and peak ground velocity), characteristics of conduit and microtopographies are analyzed respectively. The relationship between equivalent predominant frequency, which is calculated using PGA and PGV, and conduit damages are also analyzed.

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 The Mw7.8 Gorkha earthquake struck the central region of Nepal on April 25th, 2015 and caused a large number of slope failures, soil liquefactions, extensive damage to buildings and earthen structures etc. in mountains and urban areas. One section of the Araniko Highway that connects Kathmandu to China crosses a small valley at Kausaltar with an embankment. This section has sunken during the earthquake. To elucidate the cause of this ground deformation, shallow soil profiles are explored using the surface wave tomography, standard penetration tests, dynamic cone penetration tests and radiocarbon dating. The deduced soil profile suggests the presence of two weak soil layers that spread beneath the cap surface soil.

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 It is requested to implement the concept of “anti-catastrophe” property in the seismic design. The definition is still not rigorously determined. For the purpose of implementation, it is necessary to theorize the concept and create concrete output. This paper discusses the concept of “anti-catastrophe”-oriented design method, considering the effect of information. Comparison with the similar concept of resilience indicates the importance of collaboration with community. Also discussed is the design procedure, where virtual external force for the stress test of structures, and framework that encourages the information sharing between the engineers and the community. It is also presented that risk governance as the management of risk information should be recognized and that the design concept should be realized as the certification, rather than the design codes.

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