Accuracy of bending moment of single bridge column evaluated by shake table experiments was clarified using two methods; (1) method based on forces measured by load cells, and (2) method based on inertia force which is imposed to the column. It is found from implementation of the two methods to an E-Defense shake table experiment that column bending moments about the transverse direction are relatively simlar. However, about the longitudinal direction , the column bending moment evaluated based on inertia force is smaller than that evaluated based on forces measured by load cells because of the complex boundary condition in the transverse direction.

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Use of the damper using laminated high damping rubber for the seismic retrofit of an existing long cablestayed bridge is in progress. A scaled model of the laminated rubber damper consisting of plural laminated high damping rubber assemblies was examined by quasi-static loading tests for the verification of the performance as vibration control device system. The test results show that the damper system exhibits sufficient damping and energy absorption capability, and axial load dependence of the damping force characteristics is small. The masimum shear strain capacity of the high damping rubber assembly exceeding 300% is vefiried by a single-cycle and a cyclic loading tests. Therefore, the current design methodology of the laminated rubber damper is valid and can be regarded as a effective vibration control device for a long cable-stayed bridge.

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Jacket-type quay walls are classified following two types: 1) Earth pressure acts on the jacket itself; 2) Earth pressure acts on the earth retaining sections like a L-shaped block. We picked up the former type and carried out several trial designs. As a result, we found that if an arc section of steel sheet pile cellular bulkhead quay wall is adopted, construction costs decrease. Therefore the 1/20 scale shake table test compared with conventional steel pipe sheet pile retaining section was carried out toward practical use. Consequently we found that the seismic performance of both was equal less than the design seismic coefficient. The agreement of test results and their numerical simulations by the appropriate modeling of the jacket and the earth-retaining section was fairly good.

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It is important to evaluate how the seismic performance of bridges have been improved according to the revision of the design codes. The seismic performance of bridges which were designed based on 1964 and 2002 design codes were evaluated in terms of probability of suffering a certain level of damage considering the randomness of material properties. The enhancement of the seismic performance due to the progress of recent design method can be represented.

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The seismic behavior of base-isolated road brigde has been observed for more 16 years since 1991 in Fukushima prefecture. And we obtain 27 earthquake records and multi-point simultanious observation records of PC road bridge of two continuous spans supported high-damping rubber bearings.The effect of the seismic isolation was confirmed by the seismic data analysis including particle trace lines and displacement waveforms calculated by twice integrating the acceleration waves.
To investigate seismic performance of the bace-isolated road bridge during acutual earthquake, structural identification was conducted by using single-degree-of freedom model with nonlinear restoring properties. The results of identification analyses show characteristics of the skew brigde and difference of bearing distribution ratio between supporting point.

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The present study discusses strength and capacity to accommodate ground displacement of jointed fire pipes. For this purpose, a bending test, a finite element analysis and an elastic beam theory analysis were conducted. As a result, the ratio of the load capacity of the coupled joint to the welded joint was about five times. Furthermore, the bending moment and the rotation angle were identified when the inner pressure of water became the atmospheric pressure. In addition, the limit state of the welded joint was determined based on the analysis result. Finally, the displacement capacity estimated based on the elastic beam theory of the welded joint was more than about five times that of the coupling and screw joints.

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Nearfield ground motions recorded in recent years include high frequency components which make the PGA of the vertical components much higher than the PGA of the lateral components. The effect of high frequency component which was predominant in the vertical ground motion on the response of a standard bridge was studied. KiK-net Ichinoseki-nishi record during the 2008 Iwate-Miyagi Nairiku earthquake was imposed to the target bridge. It was found from the analysis that the high vertical acceleration can result in instantaneous tension in addition to high compression pulses in the bridge pier.

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Concerning the seismic performance evaluation of concrete gravity dams for Level 2 earthquake motions, when there is some fear of continuous tensile cracks between the upstream and downstream faces, further studies on ultimate seismic resistance of the dam need to be conducted. The studies include analyses to confirm the stability of the upper block of the concrete dam body separated. The shaking table tests for the test models, the shape of which is that of a concrete gravity dam, were conducted. Dynamic behaviors of the upper block of a concrete dam were made an observation during shaking. Effects of uplift acting on the separated surface of the model and dynamic water pressure acting on the face of the model on the behavior of the upper block were analyzed.

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The negative stiffness control have been proposed to achieve dynamic response reduction in terms of the absolute response. The method to decide parameters of the negative stiffness control was proposed based on the analogy to the skyhook control. However, in this method, restrictions of semi-active dampers are not taken into account. The method to decide parameters of pseudo-negative stiffness control with a semi-active damper has not proposed, yet. In this study, optimal balance of the parameters of the pseudo-negative stiffness control is proposed, focusing on the hysteresis loop of base shear. The optimal parameters are described by the parameter balance and limitation of the damper load.

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[in Japanese]

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Water supply is vital for our life after an earthquake. Prompt staff mobilization and allocation of human resources are expected for sustainable water supply. This study purposes a model to evaluate staff mobilization of water supply departments based on the results of questionnaire survey on the staff mobilization of Osaka City Waterworks Bureau during the 1995 Kobe earthquake. In this model, the time from event to office arrival and the potenstial that a staff can come to office are calculated. This model can also evaluate the time delay under transportation disruption. Simulation of staff mobilization can estimate staff availability for emergency waterworks in terms of number and response time.

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In this study, overturning criterion of unreinforced gravestones during earthquake is developed by using the 3-dimensional distinct element method. The overturning criterion estimates the height/width ratio of gravestones which overturns under a given peak ground acceleration for each frequency. The overturning criterion of reinforced gravestones with steel bar is also developed. The validity of criteria is confirmed by comparing with the shaking table results. Finally, overturning rate of gravestones in Tottori is estimated by combining the overturning criteria and the cumulative density function of the height/width ratio. The estimated overturning rate is compared with the actual data observed after the 2000 Tottori-ken Seibu earthquake.

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Various disaster information systems have been introduced to central and local governments. However, the usability of such an information system supporting disaster response management in practical use has not been necessarily sensible. In order to cut down the above-mentioned problem, the authors developed a practical disaster response manaegent system for a local government and it has been applied to Mitsuke City, Niigata Prefecture.
In this paper, 9 improvement issues on usability of the disaster response management system were extracted through workshops previously conducted in Mitsuke City. Then, the system was renewed by making those improvements. The validity of those improvements was proved through an evaluation test .

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Evaluation of damage ratio of water distribution pipes against coming earthquakes is performed by various governmental organizations. The relationship between the peak ground velocity and damage ratio of water pipes was derived only from the damage dataset from the 1995 Kobe earthquake. Water pipes were seriously damaged during recent earthquakes and the damage datasets after these events are available to construct fragility curves. This study proposes the fragilty curves for water distribution pipes and they are applied to simulate the damage distribution of water pipes after the 2007 Niigata-ken Chuetsu-oki earthquake and the damages in Chiba Prefcture due to the scenario Tokyo Metropolitan Earthquake.

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Collapse of a stone masonry wall around human living environment does not only cause safety problems to residents and passers-by but also cause a hindrance to the traffic. In this study, we perform collapse simulations of stone masonry walls during the 2001 Geiyo earthquake using discontinuous deformation analysis (DDA) in order to veryfy the utility of the DDA for the prediction of the stones spreading area as well as for the seismic assesment of the walls. We also studied the influence of the simplification of the analytical model, because the DDA tends to be unstable in the analysis for models of a large numer of mesh elements.

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In this paper, we clarify the effects of wave propagation characteristics in soft ground with a non-flat base on the dynamic behavior of railway vehicles by numerical simulation. We first ascertained the characteristics of seismic ground behavior in the out-of-plane direction in soft ground with a non-flat base using 2D dynamic FEM analysis. Next, we calculated the seismic deformation of railway viaducts constructed on soft ground with a non-flat base. Finally, we investigated the dynamic behavior of vehicles running along railway structures on soft ground with a non-flat base by using ‘Vehicle Dynamics Simulator’, which is the program developed by one of the authors.

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With requests of life-prolongation and earthquake measure, when coring the manhole wall below groundwater level was required, soil improvement methods have been often applied in order to protect ground collapse. However there are some disadvantages, such as polluting groundwater.
The authors developed SASF Method for effective earthquake measures on site, which can be set in shorter time and recover soil in 24 hours after construction, in the process of developing a device for preventing uplift of manhole in liquidized condition at earthquake. This paper shows its effectiveness through field tests.

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This paper proposes a method for promptly estimating the distribution of levels of liquefaction risk during an earthquake using a planar distribution of ground motions interpolated from seismological observation data. As an indicator of the level of liquefaction risk, the P_L value, which is used for assuming seismological damage, is adopted. The P_L value is a spot indicator obtained by comprehensively evaluating to a depth of 20 m the F_L value, the result of evaluation for liquefaction at each depth based on the geological data collected in soil investigations.
In this study, the P_L value is calculated at each point of soil investigation using a geological database, and a planar distribution of P_L values is prepared by interpolation. In the process, the calculation of the P_L value and spatial interpolation require some time, and the validity of calculation results should be verified. Then, the data that can be obtained by preliminary calculation based on the geological database is organized in a liquefaction table. It has been made possible only to retrieve appropriate figures from the liquefaction table using the data on ground motions during an earthquake.

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Various earthquake motion indices, e.g., seismic intensity, peak ground acceleration (PGA), peak ground velocity (PGV) and spectrum intensity (SI), are expected to be correlated with structual damages. This study evaluates the correlation between the earthquake motion index and building damage ratio performing seismic response analyses using numerical models of Japanese typical wooden houses. Furthermore, the SI is recalculated by changing the damping ratio and the range of period for integration process. As a result, the SI values obtained by integrations between the periods of 1.0 to 2.0 s and 1.0 to 2.5 s are highly correlated with the numerically simulated structural and actual damages.

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It is important to establish a proper recovery plan of lifeline systems against the scenario Tokyo Metropolitan earthquake. To achieve this objective, the characteristics of spatial distribution of earthquake-induced damages to lifeline systems should be evaluated properly. This study investigates the damage distribution characteristics after the 2007 Niigata-ken Chuetsu-oki earthquake. The results of this study suggest that the damaged sections of gas pipes are often found near those of water distribution pipes. Hence, the interactions among the functional losses of lifeline systems should be taken into consideration in the restoration process after coming urban earthquakes in Japan.

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In this study, we conducted a model test in 1g gravitation field and numerical analysis about seismic behavior of embankment on liquefaction ground. Test cases are non improved, and improved ground under an embankment by Chemical Grouting Method. From results, it is found that improved ground by this method has remarkable resistance against shear deformation after liquefaction, and seismic behavior of embankment can be simulated by effective stress analysis FLIP and LIQCA.

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To carry out evaluation of business impact more practically in business continuity management (BCM), we propose a new technique for quantifying the recovery time by using PERT (Program Evaluation and Review Technique) and CPM (Critical Path Method). Corresponding to the characteristics and scale of hazard, this technique can precisely predict the total recovery time based on the quantitative estimation of the time required for each recovery process, which is calculated by the current methods for damage prediction. This technique, which can show the critical path to determine the total recovery time, is also useful to decide the priority of countermeasures against the hazard.

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This study aimes to find out long-term effects of social responses in the 1994 Mindoro tsunami disaster in Oriental Mindoro, Phillipines. In the results, we found out that the resettlement policy toward residents in huge damaged areas by the government was successful so far. Rebuilding houses method “Food for Work” and improvement of infrastructure in the relocation sites were effective against the long-term success of the resettlement policy. In order to continue this success in the future, early issue of land ownership certificate for the residents who have not got ever, and continuance of disaster education in the local high schoole enveloped students' families will be essential.

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Seismic isolation method using two-dimensional device has been spread as a lesson of the cultural properties damaged by Great Hanshin-Awaji Earthquake of January, 1995. The Mid Niigata Prefecture Earthquake in 2004, however, cultural property (national treasure) was damaged in an overturn, though it was put on a seismically isolated table. After the earthquake, seismic isolation devices are becoming to be used as a combination manner with other equipments to prevent overturning, but it is not easy for even an expert of the earthquake engineering to determine whether or not giving the necessary measures to prevent overturning of the cultural properties which have complex shape. This paper describes about a computer support system to evaluate the safety of cultural properties during an earthquake.

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The authors focus on the 1995 Kobe Earthquake, and make the function of changing rate of land price before and after the earthquake. And they have analyzed the land price influenced by the earthquake. In 1996, soon after the 1995 Kobe earthquake, in the area with higher structural damage ratio, land price decreased more and in 1997, decline of the land price stopped in the areas where the rate of complete failure and burned out was high, on the other hand, it continues declining where the rate of partially damaged houses was high. From the 3rd year since the 1995 Kobe Earthquake, land price in the areas with high complete failure and burned out ratio came to rise, however, in the areas with high partially damaged ratio, land price didn't rise.

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In this study, the questionnaire survey for setting the importance of evacuation center facilities were executed. So the evaluation of evacuation center based on usability of the facility under earthquake and the method of deciding priority level for maintaining facility were presented.

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There were many “Preventable deaths” in the 1995 Kobe Earthquake Disaster. To reduce this “Preventable deaths” in disasters, standardization of triage tags has been performed, emergency base hospitals as well as Japan disaster medical assistant team (DMAT), etc. have been established. However, anxiety exists on efficiency of management of these systems. Recent disasters showed that there were issues on coordination of businesses and information sharing among firefighters, hospitals and administrative organizations. Thus, we have analyzed the current problems on large-scale medical transportation during emergency among related organizations and the effects of a common disaster information platform.

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In this paper a method of calculating restoring force characteristic by means of measurement of acceleration is proposed. A restoring force characteristic is calculated by relative displacement integrated from acceleration time series that is measured by synchronized accelerometers. A result of a measurement by a sensor system installed in an apartment building showed that a restoring force characteristic is able to be calculated by processing data observed. Numerical simulation which uses a multi-degree-offreedom system is made to show that the proposed method is capable to detect non-linear restoring force characteristics by locating an accelerometer at every second mass.

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Confirmation and securing of safety for underground space in the urban area is very important subject in the earthquake country. Underground space has been widely and densely developed in the large city such as Tokyo, Nagoya, Osaka, etc. Many citizens utilize subway and underground shopping mall in the daily life every day. The underground space has some advantages which are derived from a principal characteristic, namely isolation. However, the underground space also has some potential risks. In case of fire, flood, earthquake, terror and so forth, the disadvantages which amplify danger and directly threaten a human life may be actualized in the underground space. Therefore, in order to utilize the underground space safely and securely, it is inevitable to make clear the performance objectives of disaster prevention for underground space, and then to take preventive measures effectively. From such a necessity, the performance objectives of disaster prevention for underground space have been studied from the view points of prevention and mitigation of human disaster.

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In recent years, the simulation systems of emergency evacuation have been developed. It is required for the practical use to verify the systems by comparing the results of the simulation with the actual largescale movements in an emergency. In this study, a simulation system of emergency evacuation based on Cellular Automata (CA) is introduced. It was applied to the evacuation training which was held in a dormitory with about 500 participants, and the validity of the simulation system is discussed. The simulation system has successfully reproduced the movements in the evacuation training by taking the congestion factor into consideration.

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We propose a new approrch to facilitate damage inspection following an earthquake and a new small sensor for measuring the ground motion at the place of the target structure has been developed. The SDOF model corresponding to the structure is programmed on the sensor and the response is calculated during the earthquake excitation. The damage which the target structure suffers can be evaluated by using the result of the near real-time response analysis. The cost of the sensor is quite low because less accuracy is acceptable compared to usual earthquake observation sensors.

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In this paper, the role of organizational efforts at the local government disaster response is studied. In particular, this study aims activities of the secretarial office of Emergency Operation Center under given objectives for disaster management from incident commander. Organizational disaster response, officers collect information and manage to implement the necessary actions and public information, is designed from three viepoints (organization design, business process, and disaster information management), recorded at the operation-based exercise, and analyzed from three viewpoints.

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Earthquake countermeasures which needs immeasurable costs are not enough implemented influenced by the bad financial conditions in water suppliers and aged deterioration of water facilities in Jpan. It is necessary to win customer's understanding to progress the earthquake countermeasures. In this study we did a questionnaire for analyzing the citizen's consciousness, showing the risk by an earthquake. In the result, it was clear that the most minimum permissible usage of water suspension in disaster was toilet and the average willing to pay for water charge was higher than the actual condition. There was not a clear correlation between each question items, however, it was necessary to kick around the way to give information about countermeasures to constomers.

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This paper presents the reproductive experiments of the damage of underground telecommunication cables at the time of earthquakes in order to clarify the limit of opticalfiber cable restoration. The authors focus on the damage cases with the optical fiber cable in the NIIGATAKEN-CHUETSU Earthquake (2004) and the NIIGATAKEN-CHUETSUOKI Earthquake (2007). By modeling the seismic damage of undeground conduits for the experiment, The authors confirm that optical fiber cables are damaged not only at conduits fractures but also manholes which they are pulled into. When the characteristics of optical fiber cables on the seismic disaster are verified by experiment, it is shown that not only tension force but also bending angles causes the loss of transmission. The relation between the tension and the bending angles that the cable suffers damage is clarified. This result can be used for the rational measures to prevent the damage of the telcommunication service.

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Telecommunication conduits are connected by special conduits system for road bridges at the river crossing point. Recently road bridges are constructed or reconstructed using isolation shoe, so as to strengthen against large earthquakes. Though old conduits systems under bridges have expansion joint, which allow small displacement, it is prospected that the joint is broken by large displacement of isolation bridge. The authors have analyzed the movement of isolation bridge to clarify the influence on conduits system, and have developed new conduits system to correspond large deformation. By vibration test, it is confirmed that old system is unsafe and proposed new system is safe in the earthquake time.

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Support activities for disaster mitigation have been conducted by NPO Engineers without borders, Japan in Indonesia after the 2004 Sumatra earthquake. However available boring data and strong motion data are scarce. Swedish weight sounding test have been introduced to local engineers in Sumatra Island because the soil exploration data is essential to initiate recovery and reconstruction work and future earthquake disaster mitigation activities. Also, strong motion observation was started last summer and techniques of observation have been transferred in order to obtain ground-shaking characteristics in Padang city and the surrounding area in the close vicinity of the anticipated mega-earthquake.

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The Nankai earthquake is predicted to occur with the probability of 50-60% within 30 years. The damage from this earthquake will be brought by both the seismic ground motion and tsunami. In areas with high hazard to tsunami, it is desirable that emergency evacuation drill is carried out under the condition which all inhabitants participate in that drill, to find the latent problems of the evacuation and make them awake to tsunami risk, but it is difficult to perform such a emergency evacuation drills. In this study, a tsunami evacuation simulation system based on Petri Net was developed to solve the problem. It was shown that the simulation system proposed here was very useful to accurately simulate the behavior of all inhabitants during the tsunami evacuation. In addition, area safety index of tsunami evacuation was proposed based on the refuge completion ratio curves of area, and from some simulation results, it became clear that this index was effective for assessment of refuge safety of areas.

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This paper proposes a method to detect soil liquefaction using the zero-crossing period calculated from acceleration records based on the dataset of 112 sites including records at liquefied, liquefactionsuspicious and non-liquefied sites to understand the occurrence of liquefied sites at an early stage. As for the records at liquefied sites, the predominant period of the horizontal components tends to be longer. On the other hand, the predominant period of the vertical component is not lengthened even at a liquefied site. To reveal these frequency characteristics, the change of the period over the time was calculated from the zero-crossing period. The occurrence of liquefaction was judged by setting threshold values for the horizontal and vertical components. This method is considered to be suitable for liquefaction detection on site within an accelerometer.

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The effects of correlated component failures on post-earthquake maximum flow characteristics of the affected network are examined. Numerical integration methods and an effective simulation algorithm to evaluate the joint probability of correlated component failures are introduced. Examples are shown for small-sized representative models such as series and parallel systems with various degrees of correlation. A realistic case study is also shown for a hypothetical network. Probabilities of damage patterns and relevant maximum flows are evaluated using various evaluation methods. The simulation algorithm proposed by Genz performs well for the problems in this study.

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We investigate the simple estimation techniques about site amplification factor in Japan. About practicable 5 methods, the fundamental characteristics related to the period, nonlinearity of the soil are compared by the numerical simulation. We confirmed that relative relation of periods of grounds and structures, and the soil nonlinearity, are considered in the 4 method. It found that only a few methods can consider the earthquake intensity continuously from weak upto strong. In addition, we noted that it is necessary to consider the upper limit of the amplification factor in the weak intensity of earthquakes.

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It is very important to understand the mechanism of high speed & long-distance movement of the debris from earthquake induced landslides so as to estimate the real dangerous area. In this study, at first, a new model called Multiplex Acceleration Model (MAM) is proposed for understanding the mechanism of high speed & long distance movement of the debris. And then, model shaking table tests and numerical simulation are carried out to verify the proposed model. The MAM has been verified successfully by both laboratory model test and DEM numerical simulation. Up to 3.4 times of movement distance is observed for the earthquake with 400Gal of acceleration comparing the case without earthquake. The movement distances are different from shape to shape because the earthquake vibration causes the rotation or flying motion easily contrary to the sliding motion in the case without earthquake.

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The present paper is focusing on the damage to health care facilities in the 2007 Noto-hanto and Niigata-ken Chuetsu-oki Earthquakes. Health care facilities such as hospitals carry great importance following a disaster. Questionnaire survey was conducted for the hospitals suffering damage due to both earthquakes. The effect of the damage to lifeline and medical instruments on the performance of treatment just after the earthquake was investigated by using the result of questionnaire survey.

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In the Iwate-Miyagi Nairiku Earthquake in 2008, landslide dams and debris flows were reported. However both landslide dams and debris flows are typical disasters in case of inland earthquakes, the number of case histories on them are little in the past earthquakes in Japan. So the landslide dams and debris flows in the above Earthquake are very important to study them for the future. In this paper, the fundamental properties both on 14 landslide dams in the above Earthquake including 11 ones in the past earthquakes in Japan and 2 debris flows in the above Earthquake were discussed. As a result, several lessons on the properties of landslide dams and debris flows can be obtained.

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The role of an airport during and after a great earthquake is important as helpful existence for emergency medical service and special operation for transporting relief supplies to the stricken area. In this paper, a full-scale experiment using controlled blasting technique conducted at the Ishikari Bay New Port in Hokkaido Island, Japan, is discussed. The purpose of the experiment is to assess the performance of prototype runway pavement subject to liquefaction due to a large earthquake. Ground-penetrating radar and differential leveling before and after blasting investigated nondestructively the damage status of asphalt concrete including roadbed and underground occurred by the liquefaction. The investigation result revealed that aspects of the damages between asphalt concrete and roadbed were different.

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The present paper deals with the damage to houses in Monzen Town, especially Tohge area in Wajima City due to the 2007 Noto-Hanto Earthquake in Japan. First, an outline of damage to houses was shown and the causes of the damage were discussed in relation to the damage to residential land and the basement of the houses. Next, geotechnical survey was conducted. Then the relation between the damage to houses and geotechnical features in Tohge section was discussed. As a result, it is clarified that soil liquefaction was one of the causes of damage to houses

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The present paper deals with damage analysis of residential lands in the 2007 Niigata-ken Chuetsu-oki Earthquake. Since severe damage to residential land was caused in Kashiwazaki, City, Kariwa Village, Izumozaki City and Jouetsu City by this earthquake, an official earthquake damage judgment for residential land was conducted after the earthquake. Damage analysis was done by using the results of the official damage judgment and the characteristics of damage was compared with those in the 1995 Hyogoken Nambu and 2004 Niigata-ken Chuetsu Earthquakes. Finally, countermeasures for improvement of residential land were proposed based on the result of the damage analysis.

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An earthquake of magnitude of 6.9 on the JMA(Japan Meteorological Agency) scale occurred on 25 March 2007 near the Noto Peninsula of Japan. The maximum acceleration of 1304 cm/s/s/ was recorded at Monzen area in Wajima City. One person was killed, 341 persons were injured. The number of totally collapsed houses was more than 600, and partially collapsed houses exceeded 1,500. The strong ground shaking caused damage to lifeline systems, road embankments, settlement of port facilities and slope failures of cliffs near the sea. Liquefaction was also occurred not only ports and harbors but also residential lands. The present paper gives an outline of the damage to highway embankments and conducts the analysis of the safety factor of failure embankments. The causes of the failure also discussed based on the results of the analysis. The analysis results show that the embankment exhibited a good performance in ordinary condition. The earthquake induced force and excess pore water pressure generated during earthquake initiate the failure of the embankments.

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The present paper is focusing on the easy estimated means for slope collapses of residential land in high embankment, because residential land of high embankment was suffered severe damage in the 2004 Niigata-ken Chuetsu Earthquake. This easy change forecast evaluation technique is not described about high embankment of the belly putting type. Then, it is hoped that an immediate evaluation approach establishes it. In this thesis, because data of the situation of the type of soil of a past disaster case was a 11 little, the stability analysis on three types was done. As a result, the technique of an easy prospective evaluation the easy estimated means for slope collapses of residential land in high embankment of the belly putting type was made.

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On October 23 in 2004, the Niigataken-chuetsu earthquake, of Magnitude 6.8, has ocurred. Road embankment of the Kan-etsu Expressway slumped between Horinouchi IC and Ojiya IC. According to the soil investigation conducted after the earthquake, lower part of the embankment was saturated. Then cyclic torsion tests were conducted for some embankment soils to examine cyclic strength and shear modulus after cyclic loading. Test results showed the cyclic strength and shear modulus of partially saturated soil is greater than that of saturated soil. And the strength and shear modulus are affected by plasticity index. And, under high cyclic shear stress, failure occurred even though the sample was not saturated.

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This paper explores the possibility of improving the accuracy for the 2-dimentional effective analysis code FLIP for open-type wharves on vertical piles. We picked up the T-wharves damaged by the 1995 Hyogoken Nambu earthquake as study subject. In the past studies the agreement between the damage and simulation result was fairly good, but the problem that the buckling positions of the steel pipe piles were different was left. To simulate the buckling positions we revised model parameters as follows: 1) The appropriate modeling of shear strength of soil around the piles; 2) Using the constitutive law of the steady state of sandy soil to solve the shear locking under the earth-retaining section; 3) Using the real yield strength of steel pipe piles, not a standard value.

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