Theoretical analysis of forced horizontal oscillation of cylindrical liquid storage tanks with a floating roof equipped with a single degree of freedom vibration system was carried out by using Laplace's equation dominating the liquid in the tank and dynamic equation of circular plate simultaneously. On the other hand, model of tank was made of acrylic acid resin and the floating roof was made of styrofoam. The model was fixed on shaking table and then oscillated harmonically. Frequency responses of wave height and dynamic water pressure on the tank wall were measured. Analytical results obtained by numerical calculation agreed with experimental results obtained by using shaking table. It was indicated that cylindrical tank with floating roof equipped with a single degree of freedom vibration system was more effective for vibration control than that with floating roof only.

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During construction of membrane structures, the structures change the shape considerably and both of slack and tense area intermingle in the structures. The paper proposes a frame unit mainly composed by elastic-catenary cables that can simulate the large displacement behavior of compression-free membrane. The frame unit possesses nearly equivalent strain energy to the uniform strain element in the tense state, and keeps tensile field in the slack state. When a membrane structure is modeled in the frame units composed by cables with positive stiffness, the Newton-Raphson's method gives the equilibrium solution after large displacement by not many times of iteration under stable convergence.

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Though a lot of stone bridges in Kumamoto prefecture were administered as the variable cultural heritage, it was found here and there for stone bridges with damaged stones, gaps and falls. In order to propose the soundness evaluation method and the simply inspection method for these damaged structures, the development of the static analytical method of stone arch bridge taking into account the stone damage, gaps and falls are investigated theoretically and experimentally. The coefficient of longitudinal and shear spring between two tones was obtained from compression and shear tests and these springs was introduced into RBSM analysis. The mechanical behavior of stone arch bridges were carried out by this program and it was shown the numerical results can simulate fairly well the results of a miniature stone arch model test.

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It is well-known that isotropic metal cylindrical shells under compression have buckling behavior which is very sensitive to initial geometric imperfections. In the case of orthotropic FRP material, the angles of fiber orientation as well as the imperfection have been suggested to affect the buckling behavior in the literature. In this paper the interaction between the angle of fiber orientation and the imperfection has been made clear through the reduced stiffness buckling analysis in which imperfection effects are intrinsically considered. This paper has shown that the present reduced stiffness criteria of FRP laminated cylindrical shell under compression are insensitive due to fiber orientation and the longer wave-length mode in axial direction is important for the buckling design.

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The installation of CFRP strips of high modulus can be effective for strengthening a superannuated existing steel I girder with regard to improving its load carrying capacity. Here, shear plates of the bolted connections become obstacles in installing the CFRP strips onto the lower flange plate of I shaped steel girder. Then, experimentally investigated in this study is the strengthening effect of the methods to prevent the CFRP strips of high modulus from debonding in the vicinity of the bolted connection of lower flange plate of I shaped steel girder through a bending test. It is concluded that the proposed methods are effective to prevent the debonding of the CFRP strips and further investigations are needed to develop more effective methods.

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This paper discusses the compressive strength of corroded steel column members. Experiments were done by using two types of section: H-shaped and T-shaped. Before the experiments, the corroded shape of all 6 members was measured precisely by laser equipment and corroded thickness is calculated. For 4 of 8 specimens, maximum section deficit rate R_A was more than 0.30, which indicates the severity corrosion environment. In those 4 specimens, the remaining strength was observed to be half of a healthy member. Finally, on the basis of these experiment results, a simple equation for estimation of the remaining strength for corroded column members was derived.

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In order to estimate the ultimate strength of corroded steel members, FEM analysis is one of the most effective tool. On the other hand, however, it is required to show a simple and precise method to estimate existing ultimate strength of steel structural members making use of measured data on corrosion. This paper proposes a useful method of evaluating the ultimate compressive strength of corroded stiffened steel plates. At first, numerical analysis is carried out based on the following parameters, corroded plate thickness, corroded positions in the plate, and plate slenderness parameter, and so on. Secondary, equivalent plate thickness of the corroded plate, which is obtained by an original weighted function, is modified. Finally, proposed is a convenient column approach for predicting the ultimate strength of the corroded stiffened steel plate with a longitudinal stiffener, and validity of this proposal is demonstrated.

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In order to decrease the long life cycle cost of bridges, we are proposing box girder bridges assembled by stainless flange and web plates. The mechanical properties of stainless steels, however, differ from that of mild structural steels. Then the effect of the differences in the properties on the ultimate strength of the stainless steel plates should be clarified at first. The present paper aims to study the ultimate strength of stainless steel flange plates under compression on the basic of the non-linear finite element approach and experimental tests. The numerical results are compared with the test results, and found to be in good agreement. From the analytical investigation, it was clarified that the ultimate strength of the stainless steel flange plates under compression almost equal to those of the mild steel flange plates.

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This paper presents ultimate compressive strength of stainless steel plates made of duplex stainless steel "SUS329J3L". Because of higher strength of duplex stainless steel than ordinary austenitic one, duplex stainless steel is convenient for structural steel. At first, material properties of SUS329J3L are experimentally obtained, and stress-strain diagram is proposed. Secondly, ultimate compressive strength of two types of plates, that is, simply supported plates and outstanding ones made of SUS329J3L, is examined, and compared with that of SM570. Finally, ultimate compressive strength curves of the plates of SUS329J3L is discussed in comparison with the design curve for stainless steel plates specified by EN 1993-1-4.

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This paper describes an ultimate strength characteristics and faliure modes of radial gate strut arms under hydrostatic and earthquake loads. Monotonically static loading test was conducted using 1/4 scale strut arm models which include two H-shaped strut arms and bracing members. The result shows that the failure modes are buckling of the strut arms in vertical plane prior to buckling of bracing members. Strut arms with diagonal bracings have more ductile axial load-displacement relation than those without diagonal bracings. Ultimate strength of the strut arms can be conservatively evaluated by design strength of compressive buckling members. It is also confirmed that finite element elastoplastic analysis of the models simulates failure modes observed in the loading test.

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Hybrid girders have been considered as an economical solution, especially if they are adopted in the performance based design. In this paper, five hybrid girders were tested experimentally to investigate moment-shear interaction and behavior of web panels. In addition, hybrid and homogeneous girders with various web slenderness ratios were tested analytically. Experimental results indicated no significant moment-shear interaction. Shear strength of the experimental tests were reasonably estimated by the nominal strength in LRFD, although those of analytical results were approximately 90% of the nominal strength. Analytical results revealed that yielding of the web panels occurs in different order based on the web slenderness ratio and whether hybrid or homogeneous girders.

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Benefit from LSD introduction is apparent for the design of steel-concrete composite girder bridges. In order to establish LSD, one of issues is to get a correct evaluation of ultimate strength in plastic region. So far, such evaluating formulae have been presented mainly from EC and AASHTO LRED. However, unresolved subjects to be improved or clarified have been seen, hence, several of them were clarified in this study based on experiment. Composite test girders were subjected to sagging or hogging flexure. Ultimate flexure strength of the girder under sagging flexure, in which plastic neutral axis is positioned in the slab, was examined. Ultimate coupled flexure/shear strength was also examined. Finally, the design procedure related to this study was summarized.

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In Japan the use of corrugated steel webs is increasing in the construction of composite girder bridges. The corrugated plates have higher rigidity to shear forces but, lower rigidity to axial forces and bending. Recently, basic performances and collapse behavior of corrugated girder are clarified. However, there is no test result report concerning the corrugated web girder that receives heating. This paper presents the test results using trapezoidal corrugation configurations including a flat web that received local heating history. It is found that the local heating does not have influence on the shearing load carrying capacity because heated area is small, but affects the behavior of a corrugated web girder that received the local heating.

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Recently, there have been constructed a lot of plate girder bridges with a few main girders, which have usually thicker flanges. In this kind of bridge, flange vertical buckling of compressive flange indicated by Basler may occur, because the web cannot support thick flange enough. Therefore, bending tests and FEM analyses were conducted in this paper. And the following conclusions were obtained: 1) plate girder with thick flanges collapsed according to flange vertical buckling after yielding of cpmpressive flange, even though the width-thickness ratio of web satisfied the limit of JSHB. 2) After flange vertical buckling, bending strength decrease significantly. 3) If the web has reasonable width-thickness ratio, plate girder with thick flange will have enough plastic rotation capacity.

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Steel plates with varied thickness have a potential for rationalization of steel bridge design. For example, longitudinally profiled steel plates already have been adapted to flanges of an I-shaped girder / a box girder to reduce the weight of the bridge and the process of bridge construction. Recently, the analytical study on the mechanical behavior of steel girders with a transversely profiled web plate has been carried out, and it has been concluded that there exists the preferable cross sectional shape of steel plate from the viewpoint of the load carrying capacity and ductility. In this paper, the static loading tests for I-shaped girders with a profiled web plate in thickness are carried out. It is found that the web plate whose thickness is larger at the middle height of the girder has superiority for shear buckling strength; on the other hand, that the web plate whose thickness is larger at the close to flange plate has superiority for bending strength.

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The formula given in Design Specifications for Highway Bridges for the load-carrying capacity of a steel compressive flange is very conservative compared with the formula proposed by Fukumoto et al. However, while the derivation of the formula in Design Specifications is not very clear, the formula by Fukumoto et al. is based on the experimental data of cruciform members and its applicability to the load-carrying capacity of a steel compressive flange is not very clear. In the present study, the load-carrying capacity of a steel compressive flange is investigated by non-linear finite element analysis. It is revealed that although the formula by Fukumoto et al. is not applicable to a steel compressive flange in general, it can yield a reasonable load-carrying capacity of a practical steel compressive flange. Since the design equation for the load-carrying capacity should have some margin before the sharp drop of strength, it is also shown and discussed how much margin can be obtained by setting the design load-carrying capacity lower than the actual ultimate strength.

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In this paper, we describe the application of MPS method to a flow behavior of fresh concrete. MPS method is a kind of particle method proposed by Koshizuka. This method is suitable for the simulation of moving boundary / free surface problems and large deformation problems. The constitutive equation of fresh concrete is assumed as bingham model. Bingham model has a non-linear behavior depend on shear strain ratio, and we take into account the convergence scheme for numerical simulation. As numerical example, we perform two numerical flow analyses of fresh concrete. These are for a comparative study to evaluate the applicability of the proposed method. The good results were obtained.

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Stone arch bridge is one of the excellent heritages in the civil engineering. In order to maintain the stone arch bridges, this paper proposes a numerical analysis tool by using highly developed technologies of the finite element method (FEM). In the tool, FEM is used as a discrete deformation analysis incorporated with the friction-contact analysis. We call this method "Discrete Finite Element Model" in this paper, and we implement this numerical analysis with commercial FE software "MSC.Marc". In addition, realistic representation technique of stones in the shape and in the configuration is proposed. The realistic FE meshes are generated from measurement data using the 3D laser-scan, and the measurement date is utilized, in the pre-process of FE analysis, to identify the boundary of stones. Finally, efficiency and applicability of the proposed tool is demonstrated with numerical results for the static and dynamics strength of a stone arch bridge.

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The purpose of this study is to clarify risk perception associated with possibility of human damage of involved stakeholders due to functional impairment of critical infrastructures (FIC) in a seismic disaster. The relation between their personal characteristics and risk perception associated with the possibility of becoming bad health condition due to FIC is modeled as the structure of associated health hazard by analyzing the questionnair suvery data for lay people and by constructing the general multi-dimensional neural network classifier based on a series of Bootstrap simulation. In addition, by applying the classifier to health hazard analyses due to FIC, risk perception associated with its possibility for lay people lived in Japan is revealed representing the format of a hazrd map.

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This paper discusses the design load modeling of the debris flow which acts on the check dam structure from the view point of the redundancy of the design and proposes a new design load modeling. The actual case of a damaged steel frame check dam structure is treated with a theme of the discussion. Based on the redundancy concept which is evaluating the survivability of the structure against an unexpected load condition, the damaged accident is analyzed step by step. First, it is confirmed that the structure was designed property against the design load condition. Secondly, the uniform load of which amount is computed based on the actual debris flow condition can not be necessarily estimating the failure of the structure. Thirdly, irregularly distributed load of which total amount is equal to the uniform one causes an unsafe condition of structure similar to the actual damage. Finally, a revised design load modeling is proposed and discussed from the view point of the redundancy improvement.

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Many proposals of method for making a mid/long-term repair plan of the bridges under the jurisdiction of the municipality have been reported. In those repair plans, a detailed repair scheduling is not practical. However, the detailed scheduling is necessary for the first several years of the project, because bridges to be repaired are already determined. And, when a detailed scheduling is tried, it is necessary to decrease the user cost by the regulation of traffic during repair. Therefore, a detailed scheduling with minimizing UC by applying the genetic algorithm considering OD change is tried in this report.

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This paper discusses a FEM modeling of the filled gravels filled in the steel framed erosion control dam structures. The triangular element with linear mohr-coulomb constitute law is adopted as a model of the filled gravels so that the model can be widely used. First, by using some basic experimental results for which the rectangular shape small size steel frame are used, the constitutive law parameters are calibrated. Secondly, the semi-real size and real shape experimental results is simulated and verified by using the proposed FEM model. The verification results shows good agreement with the experimental results.

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A traffic condition often changes because the construction time becomes later several years at time when the bridge material is transporting planned. To make it apply to the road condition of frequently changing the traffic restriction by one-way traffic and construction etc. In this study, the system that supported the material transportation was constructed. Planning the transportation programming adapted to more local current circumstances in consideration of the radius of gyration, the limitation of the height of the road, weight limits of the intersection, and the traffic restriction and the restriction at the traffic time, etc. of construction becomes possible. Moreover, decreasing the local investigation frequency of the transportation programming becomes possible.

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This study aims at discussing the efficient evaluation method of failure probability of breakwaters in view of cumulative sliding displacement by Monte Carlo simulation. The target problem is different from many other problems because failure probability is judged by the cumulative displacement during the design working life of breakwaters. The fact that failure probability shall be evaluated by the repetitive actions of waves makes the adoption of variance reduction techniques difficult. The proposed method evaluates the cumulative probability distribution of sliding displacement for one year by importance sampling method and calculates failure probability for design working life by using the cumulative probability distribution.

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This study discusses the life cycle cost for sheet pile quay walls considering the progress of corrosion. It is necessary to calculate the failure probabilities according to the decrease of section modulus by corrosion for the evaluation of life cycle cost. The condition that the section modulus becomes initial value after the restoration work makes the evaluation of life cycle cost difficult. We proposed the simple evaluation method of life cycle cost and showed that the proposed method well evaluates the failure probability corresponding to the minimum life cycle cost. We also compared the failure probability for minimum life cycle cost with that for minimum expected total cost.

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This paper deals with a simple formula approximating maximum lateral response of pedestrian bridges caused by synchronized walking by pedestrians. Numerical simulations were carried out for the pedestrian bridge model with the lateral frequencyof 0.6-1.0 Hz in order to grasp the lateral response characteristics of pedestrian bridges. In addition, several pedestrian bridges suffered pedestrian-induced sways were used to verify the validity of the proposed formula. It was ascertained that the evaluation value based on the proposed method developed in this paper could be fairly in good agreement with the measured value when pedestrians walked in step with the bridge's resonant frequency.

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Fundamental study to diagnosis health condition of the bridge has been performed with the ambient vibration with structural identificaion theoryies. However, accuracy estimation of bridge dynamic characteristics may not be possible when the bridge is not well excited. Therefore, it is necessary to extract relatively high amplitude vibration data and evaluate the characteristics of the ambient vibration beforehand to apply structural health monitoring. This study pays attention to environmental factor against the accuracy of estimated dynamic characteristics such as wind velocity. Developed remote monitoring system with wind velocity triger function were applied to the existing bridge and the estimation accuracy corresponding to the wind velocity was verified.

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An automatic estimation system for bridge dynamic characteristics (frequency, damping ratio, and vibration mode) under ambient vibration by ERA, ERA/DC and PHCA method is presented in this paper. The Hankel matrix was derived from block covariance of ambient vibration data. The experiments were conducted under (a) strong wind, (b) weak wind and (c) under traffic condition to estimate the dynamiccharacteristics of existing steel langer girder bridge. As a result of this study, the better result is realized from the strong wind data. In contrast, the inducement of high frequency by the data under traffic condition leads to frequent estimation of higher mode with inconsistent level of accuracy. In the various method of analysis, ERA/DC method has the advantages for its simple algorithm and ability to provide accurate estimation with fast calculation speed.

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The objective of this paper is to show the influence of local damage in steel truss bridge on its vibration characteristic. In particular, this paper presents the results of modal analysis using vibration data of a truss bridge in damaged and repaired condition. This results show that the influence of local damage on natural frequency is small. On the other hand, influence of local damage on modal damping ratio is large and the result shows that damage detection might use it. This qualitative trend of change in modal damping ratio is also observed in the result of numerical modal analysis.

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In this research, we conduct the forced vibration test of a simple viaduct model by using the shaking table. We employ two viaduct models which are composed of the piers, the superstructure and the movable and fixed bearings. One model is excited longitudinally in the elastic and inelastic region, and the other model is excited longitudinally or transversely in the elastic region. We also conduct the dynamic response analysis of the viaduct models focusing on the modeling of the damping factor such as the material damping of the steel members, the damping due to the energy loss at the pier foundation and the frictional damping at the movable bearing. As a result, the dynamic response analysis of the sophisticated model considering these damping properties can well reproduce the dynamic behavior of the viaduct model under the earthquake motion.

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Structural monitoring is expected to improve accuracy of seismic performance evaluation of existing structures. Vibration monitoring data is suitable for composing dynamic numerical model and ambient vibration data are available instead of limited number of seismic data. In this study, a steel cable stayed bridge is modeled based on ambient vibration data and its bearing are represented in bilinear model. Validity of the model is confirmed by dynamic response analysis for recorded minor seismic waves. Then large seismic ground motions are input to the model and different action of bearing is confirmed. Hence the entire responses of the bridge are reasonable for each seismic input by using the proposed model.

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Environmental vibration problem was occurred at the house nearby the highway bridge on the soft ground. The vibration tests using test vehicle were carried out in order to investigate the cause and the characteristics of the bridge and the house vibration. As the results of the examination, it is clear that the house, which lives in complainer, resonated with the bridge. Then the keel dampers were installed at the ends of girders as the vibration countermeasure. This study evaluated the validity of the countermeasure due to running ordinary trucks. However it is necessary to compare the measured data of before and after countermeasure by the unified vibration tests. Therefore the effect of vibration reduction was examined by the dynamic response analysis due to running vehicles.

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Durations of earthquake responses of long-period structures including high-rise buildings are estimated in Tokyo area from digital strong-motion seismograph records provided by K-NET. Long-period structure is modeled by a SDOF system with damping constant of 0.01. In cases of seismograms with short time lengths, free vibrations of structures from the ends of records are considered as structure responses. At Sarue, one of the K-NET stations in Tokyo, response durations vary from 50 to 460 s, and the validity of those values is ascertained by comparison with response durations computed from JMA's low-magnification displacement seismograph records in Tokyo.

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Characteristics of stress parameter of crustal earthquakes occurring in Japan are examined in this paper. The target earthquakes are the mainshocks and aftershocks of the 2003 Miyagi-ken Hokubu earthquake and the 2005 Fukuoka-ken Seiho-oki earthquake. The stress parameters are evaluated by the Brune's equation from seismic moment and corner frequency that are estimated by comparing observed spectra at hard rock sites with theoretical spectra. The theoretical spectra are calculated based on the omega-squared source characteristics convolved with propagation-path effects. In result, we find that the stress parameter is not clearly dependent on focal depth, but dependent on seismic moment. The stress parameter obtained here is approximately average stress drop for a circular crack model but some intermediate value for an asperity model. Most of the earthquakes analyzed here are assumed to approximately the crack model except the mainshocks judging from their source sizes estimated from the corner frequencies.

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This study proposes a method of generating synthetic ground motions that fit the attenuation relationship of acceleration response spectrum, taking into account non-stationary effect. The authors previously proposed a method of generating ground motions based on stationary random process. This study develops our previous method so as to take into account non-stationary effect of ground motions incorporating a correction function that modify the calculated response spectrum for different types of earthquakes. The results shows that calculated response spectrum fits very well with the target response spectrum for various earthquakes of different magnitudes, focal depths and hypocentral distances.

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In this study, we focus attention on an interlocking reinforcement measure for European-type gravestones using steel bars. This reinforcement measure is widely used, but there are no specifications as to how long, how thick and how many steel bars should be used. First, results of 3-dimensional shaking table tests of full-scale gravestones with and without steel bars are investigated to clarify the effect of thickness, length and the number of steel bars on the seismic behavior of European-type gravestones. Then, the DEM analysis is conducted for more elaborate study. Finally, an optimal retrofit measure using steel bars for European-type gravestones is proposed.

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The present study is discussed about the seismic risk assessment of steel tanks when a strong earthquake excitation develops a plastic deformation of base plate by a rocking motion of the tank.
Current seismic design guidelines underestimate the seismic safety of buckling failure at the side wall, because the stiffness degradation of the tank is overestimated with the structural characteristic factor Ds.
The present study proposes the exact estimation approach of the seismic safety of elephant foot buckling failure at the side wall as well as the crack failure of the base plate. The seismic performance of the tank is also developed on the limit state design method to provide the fragility curves for the damage modes of the side wall and base plates.

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The predicted damages of existing airports after earthquake have been investigated recognizing their important roles at the time of disaster. In the improvement of the ground to strengthen its deformation resistance, rational improvement area should be determined on the basis of the performance-based specification instead of conventional descriptive specification leading to the whole improvement of liquefiable area. In this study, a stochastic method is proposed for evaluating the effect of partial and rational soil improvement for liquefiable ground. The validity of the proposed method is verified by conducting an experiment in the use of underwater shaking table. In addition, a case study is numerically conducted for a model airport.

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A constitutive model is proposed to evaluate volumetric change during and post liquefaction. Conventional models used in this issue have fatal shortage to be used for post liquefaction consolidation analysis; volume change is uniquely determined by the change of effective stress from the liquefaction to the complete excess porewater dissipation. In other words, they cannot explain the fact that volume change depends on amount of loading during liquefaction. Then a new volume change model is proposed, in which modulus is expressed as a function with respect to effective stress and dilatancy. This model has several advantages compared with conventional models. Dependency of volume change on loading is considered, therefore this model can be used for during and post liquefaction. Numerical calculation is made and this model is shown to work well.

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In order to investigate the applicability of the effective stress analysis for the seismic assessment of a river dike during a long-time-duration-earthquake, we conduct the earthquake response analyses based on two analytical codes using two type earthquakes. One is a sinusoidal wave which is frequently used for shaking table tests, and the other is a long-time-duration-earthquake such as a subduction earthquake. From the results of earthquake response analyses, the difference of the prediction crown settlements of the dikes between two codes using the long-time-duration-earthquake is larger than one using a sinusoidal wave. We consider this tendency is derived from the difference of modeling for the characteristics of the post-liquefaction phenomena.

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The standard earthquake resistant design method of quay wall against a level-one earthquake ground motion is a pseudo-static method and is not necessarily in harmony with the failure mechanism of quay walls. Therefore, authors proposed a frame model for the evaluation of the seismic performance of sheet pile quay wall with vertical pile anchorage in the previous study. This study aims at improving the frame model proposed in the previous study for the precise reproduction of the deformation of quay wall. Major improvement was made on the evaluation of soil reaction spring model for the deformation of sheet pile and the model for the calculation of residual deformation of soil layers beneath the sheet pile.

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Under water shake table test and 2-dimensional effective stress seismic response analyses were conducted to investigate the behavior of cellular-bulkhead qway wall structure model. The results show that the settlement and horizontal displacement of bulkhead was caused by shear strain accumulation of cell fills. Results of dynamic response analysis is almost agreement with those of the shaking table test. Seimic performance of cellular-bulk head qway wall is verified.

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A framework to evaluate functional impairment of elevated bridge systems during a seismic event is proposed. Firstly, by analyzing the data associated with the damage of structural components of elevated highway bridges on route No.3, Hanshin Expressway, the fragility curves of a deck, a pier, and a bearing are derived. Secondly, by combining the fragility curves and seismic hazard map, the framework to derive the seismic loss function and the risk profile including the information associated with the direct and indirect loss due to the seismic damage of a bridge is shown. Finally, based on the framework, case studies of the variation of seismic hazard and the effect of traffic delay are carried out.

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The giant earthquake of Mw=9.3 and the induced tsunami in December 26, 2004 caused the catastrophic damage of infrastructures such as coastal structures, utilities and transportation facilities. In this study, the hydraulic experiments were carried out to clarify a tsunami wave load to a bridge deck, focusing on the clarification of the dependence of the bridge deck lateral movement on a wave height induced by a tsunami. Maximum ratio of the drag force to the deck weight becomes 0.43 to 0.44, that means the boundary lateral load by which deck movement occurs.

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To evaluate the wave force to the bridge by the tidal wave, the experiment was executed. We measured the wave force, the lift force and the wave pressure in the experiment. We compared the equation of the wave force drived Goda or Asakura with the measured wave force. The wave pressure drived the measured wave force greatly exceeded the wave pressure drived Goda or Asakura by the situation. The lift force was 3.0 times as large as the wave force, and we should consider the lift to the design of the bridge.

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More than 70 girders were washed away by the Off-Sumatra Earthquake and ensuring Tsunami. Numerical Analysis using DEM was performed to investigate the failure mechanism. The result showed, as flow velocity of Tsunami increased, the acting force to the girder and total movement of girder increased. Whether the movement of girder occurred or not is controlled by the coefficient of friction between the girder and beam, and the flow velocity of Tsunami.

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A new type of fixed support bearing that has a cylindrical steel element (Shinbo) was developed for a horizontal load resisting mechanism. During its development process, the newly developed support bearing was subjected to various evaluations including experimental evaluations. By conducting full-scale model and half-scale model loading tests designed to examine the horizontal load resisting mechanism, this study investigates the effect of the horizontal load resisting mechanism on horizontal load carrying capacity and the failure mechanism in the cases where vertical loads act or do not act and where uplift loads act.

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A seismic retrofit of existing bridges using a bearing support with knock-off functions and a performance confirmation experiment were conducted. As a result, the responses of piers were reduced in elasticic ranges within the permissible values. By changing the horizontal support condition in the transverse direction into movable from fix condition, it was confirmed that the superstructure was behaved elastic responses. After performing a performance test of the knock-off bearing support, valuable information was collected for fracture and strength characteristics notched bolts. Furthermore, it was confirmed that the bolt was fractured at a load satisfying the required performance from the seismic design.

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Seismic performance check and seismic retrofit study against a Level-2 ground motion was performed for an existing upper-deck type steel arch bridge. Dynamic analysis with geometric and material nonlinearities was carried out by using a 3D fiber model. The allowable value of main members such as arch ribs was verified from serviceability point of view after earthquake by FEM analysis. As a result, the main members were remained elastic. For the sway bracing and lower lateral bracing caused transverse buckling and thus reduced strengths, an efficient retrofitting method by energy absorption is proposed to prevent these buckling.

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This paper performs the earthquake response analysis of two-storey steel portal frames. The shear buckling behaviour of web plates in the middle of the 1st storey beam is paid attention to by the substructure pseudodynamic testing method. The implicit time-stepping algorithm is based on the α-OS method to solve the equation of motion. The numerical results illustrate the non-linear response of frames including the remarkable change in shearing resistance force of web plates due to buckling and diagonal tension-field. The damage mechanism of frames is discussed by focusing on whether or not the shearing collapse of web plates in the 1st storey beam could save the damage of another structural parts.

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