In the 1995 Hyogoken-nambu earthquake and so on, many structures with pile foundation have received damage at upper part or soil layers boundary part of piles and at building columns or bridge piers of he superstructure. In this places, relationship between ground and earthquake-damaged parts of structures with pile foundation has been investigated in both the case study and the seismic response analysis. It has been found out that many damage of columns or piers had occurred at the gravelly and/or sandy ground with comparatively thin and soft soil layer, pile damage has occurred in the soil layers boundary part within its ground, and particularly upper part damage of piles has occurred in the reclamed land on soft soil ground with void under the footing. It has been found out by seismic response analysis that their damage has been occurred at stress concentration part of structures.

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In general, seismic intensity, peak ground acceleration (PGA), peak ground velocity (PGV) and spectral intensity (SI) have been usedasthe indices of destructive poweron earthquake motion. However, it is quite important to consider the number of earthquake response cycles in the vicinityof the maximum response andnatural period of structures for predicting damage to structures. Especially, destruction of thewooden structure was expanded byaftershock after the main shock in 2004 Niigata-ken Chuetsu earthquake. In this study, the influence byaccumulation of the earthquakemotion on wooden structure destruction is considered. The fatigueresponse spectral intensity (FSI) of havingtaken the repetition of earthquake motion into consideration is applied, and a relation with wooden structure damage is considered. Inaddition, existing probability of natural period of wooden houses is taking into account in this index. In this study, It is predicted to thewooden structure damage using the FSI indexin Kanazawa City. As a result, it was clarified that accumulation of an earthquakemotioninfluences structure damage and the earthquake motion destructive power index proposed by this research that accumulation of the earthquake motion can be taken into consideration is effective.

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The Noto Hanto Earthquake occurred on 9: 42, March 25, 2007. The magnitude of this earthquake was 6.9 (determined by JMA) and the maximum JMA seismic intensity was upper 6. Liquefaction of soil was observed at many places in Noto peninsula during this earthquake. Liquefaction of soil was also occurred in Noto peninsula during the Noto Hanto-oki earthquake in 1993. Some liquefaction phenomena were observed the same site where liquefaction occurred during the previous earthquake. Characteristics of liquefaction sites, damage due to liquefaction, re-liquefaction, grain size distribution of sand boil and results of liquefaction judgment calculated at three sites are discussed in this paper.

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We conducted microtremor measurements in areas devastated by the May 2006 Mid Java Earthquake in order to estimate the correlation between the result of measurements and damage. We showed that we could estimate the seismic response characteristics of the surface ground over the huge area and there was strong correlation between those two overall. The reason why we could not see some correlation in a particular area is seemed to be because of the source property and the propagation property. In a landslide region, we could roughly estimate the amount of sliding soil mass by using quarter-wavelength method. Besides, we could estimate the seismic response characteristics of some structures: historic architecture, dam and typical house (brick masonry), and as the result, we showed that there was a possibility that resonance would happen during earthquake.

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A very large earthquake with a magnitude of 8.7 occurred nearby Nias Island of Indonesia on March 28, 2005. Strong ground motions induced heavily casualties and damages to infrastructures such as roads and bridges, and buildings. Permanent ground movements such as settlement and lateral spreading, and associated structural damage due to liquefaction were widely observed in various locations along the coastal area and reclaimed ground. Many bridges were damaged by strong ground motion and permanent movement of abutments as a result of lateral spreading of liquefied ground. Many buildings were heavily damaged due to partial settlement, inclination and uplift of ground floor in the reclaimed area in the coastal region of Gunung Sitoli. The Swedish Weight Sounding Test were introduced and conducted by local enginners in Nias Island in order to initiate recovery and reconstruction work.

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An earthquake with a magnitude of 6.3 has occurred on May 27, 2006 and caused 5, 700 casualties. Investigation on damage for the Prambanan temple, housing and infrastructure was carried out in and around Yogyakarta, in central JAVA from June 5 to 8, 2006 The Prambanan complex sustained heavy damage, even this complex is located 40 km far north east of the epicenter. It is considered that the seismic wave was amplified due to the directivity effect and attacked Prambanan complex. Extensive damaged areas are distributed in the west side of the Imogiri fault. Serious damaged areas are limited in Bantul and in Klaten Regency. Damaged areas begin in Klaten Regency between Solo and Yogyakarta. In Bantul Regency, there were more than 4, 000 casualties. The infrastructure suffered comparatively light damages, however, housing sustained heavy damages and totally collapsed in Bantul Regency. In this report, reasons why the infrastructure sustained light damage while housing suffered heavily and as well as why damage areas are distributed unevenly are discussed.

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The 2003 Sanriku-minami earthquake caused severe damage to residential land in Ishinomaki, Tsukidate, Kesennuma, Sendai, etc in Tohoku region in Japan. Emergence damage evaluation of the residential land was conducted by the firemen at the second and third days from the earthquake. Official judgement of safety evaluation of the residential land was performed in one month after the event. The present paper compared the both evaluation in order to analyze the characteristics of damage to residential land, Moreover, a problem of delay of the official judgement was discussed.

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The present paper deals with improvement of official earthquake damage judgment system to residential land. This system started from the 1995 Hyogo-ken Nambu Earthquake. The system worked well in the 2000 Tottori-ken Seibu, 2004 Niigata-ken Chuetsu, and 2005 Fukuoka-ken Seiho-oki earthquakes. The problems of the system also pointed out through these experiences. Therefore, a questionnaire survey concerning with the problems was conducted for the persons who worked under the system after the 2004 Niigata-ken Chuetsu Earthquake. The paper analyzes the result of questionnaire survey and proposes a improvement of the system.

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For the realization of efficient organization disaster countermeasures, it is necessary to analyze/evaluate past disaster response, identify problems, and examine their solutions. In this paper, the records of the Niigata Prefectural Government disaster response actives during the Mid Niigata prefecture Earthquake in 2004 are analyzed from five viewpoints (constitution, job analysis, business amount evaluation, information management, and mutual relation). The reliability of those records was verified through hearings with the relevant prefectural government staff. Based on the analysis and discussions, the authors make the environment to propose countermeasures that aim at improving the organization disaster prevention power.

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There are many uncertainties, such as the frequency of occurrence, magnitude, and extent of anticipated damage, in assessing risk related to natural hazards, such as earthquakes and floods. Therefore, a natural hazard risk assessment method that incorporates the theory of probability is being introduced. As just described above, many studies are made on natural hazard risk assessment methods and the methods are applied to practical business. Many regions of this country are often hit by two or more natural hazards, such as earthquakes, typhoons, heavy rain, and snow, and volcanic eruptions. To draw up appropriate proactive and follow-up programs for disaster damage prevention, it is necessary to study a multiple natural hazard risk assessment method. This paper describes a proposal of practical method to assess multiple natural hazards and the case studies of the multiple natural hazard risk assessment based on the results of researches achieved up to now into the methods of assessing risk associated with individual natural hazards.

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In designing road or railway facilities, the Level 2 earthquake is evaluated mainly from the records observed in the 1995 Hyogo-ken Nanbu earthquake. These records were observed at the site, where the strong motion was largely amplified because of the influence of the deep seismic bedrock. However, the ground motion is not so much amplified at the site with the shallow bedrock. We, therefore, propose the response spectra for the Level 2 earthquake considering the depth of the seismic bedrock. In the area of shallow bedrock, we can make the designed spectra about 30 percent smaller than that in the deep area at the longer period. Using these proposed spectra, structures can be constructed more reasonably on the stiff ground in the mountain side etc.

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We study variations of predicted ground motions on the basis of a recipe for strong-motion prediction and propose a technique for evaluation of variation in the predicted ground motions. In this article, we consider only aleatory variabilities in source parameters among all possible variabilities, such as, those in the source parameters, the propagation characteristics and the site characteristics. We estimate the variation of predicted ground motions in PGA, PGV and response spectrum at a specific site and calculate average and standard deviation of normal distribution, and also we evaluate the special variation in the area by using the space distribution maps of standard deviation.

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In conventional papers, the author pointed out the importance of the role of multiple nonlinear effects in strong motion prediction and proposed a simple method to take into account the effects by correcting empirical Green's functions using “nonlinear parameters”. In the present article, it is proposed that the method using nonlinear parameters should be convined with conventional effective stress analysis to consider the effects of soil nonlinearity more appropriately. The convined method is applied to strong motion records from the 1995 Hyogo-ken Nanbu (Kobe) and the 1993 Kushiro-oki earthquakes and its validity is investigated.

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A method of estimating earthquake ground motion using microtremor horizontal to vertical (H/V) Fourier spectral ratio is presented. Inthis method, an earthquake ground motion is estimated from the earthquake ground motionrecorded in thenearby observation site by usingthe correction factors which consist of the microtremor H/V spectralratio of the both sites (the reference site and estimation site), the path effect factor of waves β, and the site factor ofvertical ground motions γ. By using the observed microtremor records andearthquake ground motions in the Miyazaki Prefecture, the presented estimation method is examined. And also the error of estimation of Fourierspectral amplitude of earthquake horizontal ground motion is discussed.

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[in Japanese]

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Fourier Transform, which is widely used for seismic design purposes, is not to describe the temporal variation of frequency characteristics (time-frequency characteristics) and therefore not necessarily suitable for input motion synthesis. We propose a scheme to use wavelet transform in a manner familiar to users. The performance of the proposed scheme is verified by numerical simulations.

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This paper proposes two methods to estimate the similarity of ground motions based on the probability density function of nonlinear response of strcutures with parametric uncertainty. One uses mutual information to estimate the difference of the probability density functions and the other Kullback. Leibler divergence. The performacne of the proposed methods are discussed by numerical simulations using artificially modified strong motion records. It was presented that the proposed methods rationally estimate the range of modification.

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The source rupture process during Niigata Chuetsu Earthquake was estimated by kinematic source inversion using observed waveforms at 9 stations. Subsurface structures of each station were modeled to calcurate theoretical Green's function, verified by comparing between observed and wavecalcurated waveforms of aftershocks. The estimated slip distributions provide that the waveform at JMA-KWG was generated by the shallow region of the fault, which is located above the main asperity, while waveform at NIG019 was generated by the main asperity.

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In order to produce a detailed seismic intensity map which aids regional disaster planning, a seismic intensity survey using paper-based questionnaire was conducted at Tsurumi ward, Yokohama in the northwestern Chiba earthquake (M6.0) on July 23, 2006. About 8, 000 questionnaire sheets were distributed and more than 3, 000 were collected. From the survey, the detailed seismic intensity distribution was revealed, showing that the distribution is very complex and that the intensity at a lowland is not necessarily larger than that at a plateau. To interpret the complex intensity distribution, the relation of the intensity with the ground condition is examined.

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In order to investigate the relationship of the strong ground motion and the damage of soils and houses, the distribution of earthquake ground motion during The Noto Hanto Earthquake in 2007 (MJ=6.9) was evaluated from the observation records taking account of amplification factors of shallow soil deposits. In addition, in order to clarify the site effect during the Noto Hanto Earthquake, strong motion records of several events at two near observation sites were compared for each area. It is found that site amplification and nonlinear characteristic is very important.

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This paper discusses groundmotion attenuation and site amplification by using long-period earthquakes that occurred near the epicenter of the 1944 Tonankai-Earthquake. The long-period earthquakes were observed at K-NET andKiK-net sites in the wide area ofShikoku. Comparison with attenuation relationship proposed byMidorikawa orAnnaka showedthatPGAas wellas PGV of the long-period earthquakes becamemuch smaller than Midorikawa's evaluation, whereas peak ground displacements showed good fits with Annaka's attenuation relationship. As for the site amplification, the observed records show that long-period motion are less amplified compared to other earthquakes of ordinary characteristics. These results indicate that the ground motion could be overestimated for the long-period earthquakes if the motion is estimated based on the ever-developed attenuation relationships and site amplification equations.

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In Japanese seismic design for railway structures, the surface ground is classified into eight types by its natural period, which is computed based on the initial rigidity of each soil layer. If the level of the input earthquake motion is larger, however, the rigidity of the surface ground becomes smaller. The accuracy of type of soil is, therefore, affected by the nonlinear characteristic of each soil classification. In this paper, we propose the method to calculate the equivalent natural period of surface ground taking into account the soil classification and try to classify the ground based on the period. We verify the efficiency of our proposed method by comparing with the results obtained using the type of soil shown in the current design standard for railway structures.

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We examined grouping of site amplification factors using the H/V spectral ratio of microtremer to evaluate appropriate design ground motions in Tokyo Port, in which site amplification factors have been evaluated at sevelal strong motion sites using seismograms. In regard to the frequency range from 0.3-2.0 Hz, which affects the seismic performance of port structures, the peak frequency of the H/V ratio shows good coincidence with the peak frequency of the transfer fanction of the local soil layers which is controlled by the layer boundary with large impedance ratio. A simple scheme is illustrated for the grouping of site amplification factors using the amplitude of site amplification factors and the peak frequency of the H/V ratio of microtremer.

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A dataset of instrumental seismic intensities recorded at 50starions in Tottori Prefecture, southwest Japan, 1464 events (4833 records) has been compiled. An average difference between recorded seismic intensities and those estimated using the attenuation was defined as an index representing the site amplification; standard deviation and number of observations were also used. Relationship between the index and subsurface ground structure was studied. There was a correlation of the index with AVS30. At close two stations in Sakaiminato City, we analyzed a difference of instrumental seismic intensities the same method. The difference of two stations was confirmed on this analysis.

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We examined arelationship between topographical classification, altitude and site effect of K-NET, KiK-netstations inHokurikuregionin this study. The lower frequencyof site effect, the more highly site effect correlate toaltitude. The averaged site effect with respect to topographical classification were evaluated. The averaged site effect ofobservation sites at hill is large in frequency band between 1to 3Hz, and those of delta coastal low land, back mash is large in frequency band lower than 4Hz. Moreover, coefficients of variation of site effectwith respect to topographical classification wereevaluated. We clarified that the coefficients of variation of site effect of mountain, hill and back marsh were small, and those of gravelly terrace and valley bottomlaw land were large in a arbitrary frequency band.

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We observed microtremors at 400 sites and microtremor arrays at 4 sites, in the Izumo plain. S-wave velocity in quaternary and the distribution of predominant periods were determined by microtremor array observation and H/V (horizontal-to-vertical) spectral ratios, respectively. The average S-wave velocity in quaternary was found as 230m/s. The predominant periods in H/V spectral ratios will provide individual thickness of quaternary following to the quarter wavelength law. We estimated the thickest value at about 10 to 100m with the predominant period of 0.2 to 1.8s, and it looked quite reasonable as we confirmed similar result in the geotechnical information.

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Coupling effect between horizontal and vertical behavior is investigated through the three-dimensional effective stress earthquake response analysis. The interactive effect is hardly observed in the saturated homogeneous model ground under the sinusoidal input motion in both horizontal and vertical directions. The coupling effect appears, however, in the unsaturated ground; effective confining stress changes under vertical motion, and vertical motion appears under the horizontal vibration because of dulatancy effect. Finally, the Port Island vertical array record obtained during the 1995 Hyogo-ken Nanbu earthquake is simulated, and the behavior observed in the preceding analysis is confirmed to occur.

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There is the feature that an ocean type earthquake has the long continuation time of an earthquake motion. This research conducts the shaking table test of a caisson type quaywall, and the feature of liquefaction of a different continuation time is examined. With the small acceleration with loose sand, the influence of continuation time is great, and after liquefaction, the pore pressure keeps high. In the case of dense sand, influence of continuation time is small, and pore pressure disappears promptly. To convert the acceleration of a scenario wave with oneof a rule wave, it is necessary to also take density into consideration.

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The 2004 Niigata-ken Chuetsu earthquake in Japan caused serious damage to sewage facilities such as uplift of manholes and settlement of pavement above backfill soil for pipes. This paper deals with shake table tests in a 1-g gravity field on application of recycled materials for ground improvement to mitigation of liquefaction-induced flotation of manhole during earthquakes. The recycled materials used in tests were tire chips made of waste tires and crushed gravels made of waste reinforced concrete, and they were packed in sandbags. From the test results, it was confirmed that the recycled materials packed in sandbags could be treated as one of the countermeasures to restrain the flotation of manholes and settlement of ground surrounded by sandbags.

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This paper presents a probabilistic method for assessing the liquefaction potential of cement-treated sandy ground, which is an anti-liquefaction ground improved by cement-mixing. The proposed probabilistic method considers the inherent spatial variability of unconfined compressive strength in the cement-treated ground, the random testing error of unconfined compression tests, and uncertainties in the regression analysis to estimate the liquefaction resistance in cement-treated sandy ground. The percentage of liquefaction zone in the ground and the liquefaction potential index are calculated to evaluate the potential of liquefaction in cement-treated sandy ground. Finally, the effectiveness of cement-mixing for sandy ground to prevent liquefaction is discussed based on the result of the application to three construction sites of cement-treated sandy grounds.

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The anti-liquefaction ground improved by cement-mixing and permeable-grouting shows the spatial variability of liquefaction strength resulting from the spatial variability of original soil profile before treatment, the non-uniformity of mixing and grouting, etc. The seismic behavior of improved ground with the spatial variability of liquefaction strength, however, has not been fully clarified.
In this paper, in order to evaluate effects of spatial variability of liquefaction strength on the seismic behavior of improved ground, a series of model experiments has been carried out through investigating the seismic behavior of partially improved ground using shaking table test. Moreover, the estimation of seismic settlement considering the depth distribution of vertical strain in terms of 1 dimensional (1D) and 2 dimensional (2D) improvement patterns has been proposed. It can be seen that estimated seismic settlement from 2D improvement pattern shows better agreement with observed settlement than 1D estimation.

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To mitigate liquefaction-induced settlement of levees, improvement of liquefiable foundation ground by cement is often adopted. In this study, mechanical properties of sand improved by cement in grid pattern were examined by means of the direct shear tests on the improved sand. Test results reveal that the unimproved sand in drids prevent out-of-plane deformation of improved soil walls arranged in grid pattern and makes the shearing resistance of the overall improved zone. It is also found that the stress-strain relations of the sand improved in grid pattern can be a unique line when they are normalised by the unconfined compression strength of the cement-treated sand and improvement ratio.

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A series of undrained cyclic shear tests was performed on compacted samples of Shirasu to assess the influence of grain size distribution and confining pressure on the liquefaction susceptibility. For loose samples of Shirasu, different kinds of cyclic strength characteristics were defined in this study. For the cyclic shear strength of sandy soil with gravel is independent of initial confining pressure. On the other hand, for gravely Shirasu the cyclic shear strength decreases significantly with increasing confining pressure. For all dense and compacted samples, the cyclic shear strength decreases remarkably with increasing confining pressure. However, it was recognized that decrease tendency of cyclic shear strength for Shirasu due to compaction depended on grain size distributions.

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This paper presents a method of estimating the elastic properties of the soils and their variation with depth using the characteristics of P-SV wave propagation in layered media and their dynamic response due to the vertical harmonic point load applied on the soil surface. To demonstrate the capability of the presented method, the two numerical examples are presented, for the estimation of the S wave velocity, P wave velocity and thickness of each soil layer using a single layered medium and the three-layered media overlying on a half space medium. In the numerical examples, a stiffness matrix method for acculately calculating wave field is used.

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Many seismographs have been installed in Japan since the 1995 Hyogoken-Nanbu earthquake which brought severe damages to around the city of Kobe. National Research Institute for Earth Science and Disaster Prevention (NIED) deploys digital strong-motion seismographs (KiK-net) all over the country in Japan, which provide vertical array records of ground motions. The total number of observation sites is nearly 700. Data observed by KiK-net can be used to identify the dynamic properties of the subsurface ground. In this study, a new approach is proposed to identify the quality factor, and its problem is discussed.

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The embankement on tilted bedrock often suffers seismic damage in the previous strong earthquake; however, there is few previous study on the seismic response characteristics of the embankments on such a tilted bedrock. Based on shaking table test results in a centrifuge, the effect of the gradient of tilted bedrock on the seismic response were examined in this study.
The test results were compared with the estimation by the Newmark method for embankement on tilted bedrock. It revealed that the cross-spring model can contribute to Newmark method by the estimation of dynamic response of embankment.

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The embankement on tilted bedrock often suffers seismic damage in the previous strong earthquake, and the level of vertical seismic motion by the earthquake in recent years was powerful; however, there is few previous study on the effect of the vertical seismic response of the embankments. Based on the seismic response calculation results using a FEM code ‘FLIP’, the effect of vertical earthquake motion on seismic performance of embankments with tilted bedrock were examined in this study.
The results indicate that the effects of the phase characteristics of the input earthquake motion in both horizontal and vertical motion are significant.

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The damage of the embankments on tilted bedrock is reported in recent earthquakes. However, there are few studies about the characteristics of seismic response of the embankments on such tilted bedrock, and the effects of a vertical seismic motion on the damage to earth structures are not investigated well.
In this fundamental study, the equations for the natural frequency in the horizontal and vertical direction considering the shape of embankments were proposed. Then, the proposed equation were examined with the results of shaking table tests and the FEM calculation result.

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The SPH method is capable of dearing with extreamely large deformation problem. Recently, the authors are tring to apply the SPH method to solving the large deformation of soils due to strong earthquake motions. In this paper, the SPH method is adopted to the effective stress analysis of shear soil column. The results of our numerical simulations show good agreement with those of the laboratory tests.

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In this paper, the locality of liquefaction in stabilized ground is expressed on the random theory and the bearing capacity under seismic loading is analyzed through Monte Carlo Simulation with Numerical Limit Analysis. The purpose of this paper is to clarify the effects of local liquefaction in ground and the pattern of liquefaction on the bearing capacity factor under seismic loading. As a result of this analysis, following conclusions were obtained. (1) The distribution of bearing capacity factor under seismic loading considering the locality of liquefaction can be expressed by log-normal function. (2) The bearing capacity factor under seismic loading decreases with the increasing the area of local liquefaction in ground and horizontal seismic coefficient. The liquefaction ground has no clear slip surface and comes to destruction with a little deformation. (3) The bearing capacity factor under seismic loading and the failure mode against seismic loading depend on the pattern of local liquefaction.

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Recently, coupled effective stress dynamic analysis is gradually used to calculate the residual displacement induced by the earthqueck including the possible liquefaction. The evaluation of seismic deformation performance is dependent on the finite element code, constitutive laws and its parameters, and so on, so the reliability of numerical analysis is still discussed and should be improved now. This paper proroses to use seepage analysis, static finite element analysis, and coupled effective stress dynamic analysis to calculate the deformation of Lower and Upper San Fernando Dams induced by the San Fernando Earthquake. The major slide for the Lower San Fernando Dam and the residual deformation for the Upper San Fernando dam was re-produced well.

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Shaking table test and numerical analysis with dinstinct element method on earth dam were carrid out to establish the perfomance-based design. The numerical analysis could reproduce the results of model tests. In additionally, the resluts from the model tests and numerical analysis showed that the level of damages in earth dams could be expressed by the ratio of the settlement and height at the crest. A criteria related to the damages in earth dams was proposed in this paper.

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Earthquake resistance of pile foundations, constructed in composite ground which was formed using deep mixing method for the purposes of improving shear strength in soft ground or sandy ground subject to liquefaction was verified through a two-dimensional nonlinear dynamic finite element analysis. As a result, it was revealed that the displacement of pile foundations and the strain of piles were restrained by composite ground around piles, and that the earthquake resistance of pile foundations was improved. It was also found that the earthquake resistance of pile foundations depends on the improved strength, the range of composite ground. The composite ground pile method is applicable for both Level 1 and Level 2 earthquake loadings.

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The column at end of the Joetsu Shinkansen railway viaduct ( whose name is The 3rd WANATSU viaduct. rigid frame structure) reached a shear collapse after yielding of main reinforcement in The 2004 Mid Niigata prefecture Earthquake.
The space under the Rigid Frame Structure was used as a snow melting machine room, so that the base concrete which has underground beams and steel tube piles for supporting machine weight existed.
This paper says that the main reason why the column reached a shear collapse was binding the middle point of the colomn with the base concrete and backfilled soil, reporting acutual damaged situation and analyzing the structure by using 2-D FEM method.
And, we report the influence of the base concrete and the backfilled soil to column collapse mode from the result of some parametric studies.

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In the performance based design, it is important to evaluate deformation performance capacity of structures. Deformation performance capacity of piles, however, should be considered by focusing more on the relation between subgrade and deformation performance capacity of shaft. In this study, a series of RC pile cap loading tests in air and dense sand are conducted by focusing on deformation performance capacity of RC pile cap, which often has serious damage during earthquake. As the result, ductility capacity is little dependent on subgarde, but restoring force is subjected to lateral resistance of subgrade, and the problem to lateral resistance of subgrade at design code for railway structures is presented.

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In the dynamic analysis of bridges, a brigde foundation is simply modeled as sway-rocking spring model (SR-Model). It is necessary to take account of the nonlinear soil-structure interaction to determine the characteristics of spring elements. However, such elements are generally given as simple values in the usual dynamic analysis regardless of the strain amplitde of soils, foundations types, and soil conditions.
In this research, the damping factors for the SR-model are analysed through 3-D FEM model using thinlayersd element method and the comparison of the response functions between FEM model and SRmodel are made.

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Deformation behavior of buried pipelines subjected reverse fault action was investigated. Characteristics of ground-pipeline interaction (subgrade reaction) in case of the upward pipe movement relate with the ground were investigated by the centrifuge experiments.
Results show as follows. (a) Reaction force of cover soil is propotional to both pipe diameter and buried depth. (b) Coefficient of subgrade reaction is in inverse propotion to pipe diameter. (c) Coefficient of subgrade reaction has the maximum velue related with pipe displacement. (d) Maximum subgrade reaction of cover soil can be evaluated by the design fomula proposed in the Standard Practice of Seismic Dedign of Buried Pipeline on the Liquefable Ground, published by JGA.

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Design input earthquake motions considering influence of characteristics of earthquake source fault and soil deposit are being used in seismic design of structures in recent years. It is becoming necessary to examine the behavior of the structure under ground motions with period and duration property which had hardly been taken into consideration. A series of gravitational and centrifugal model tests was conducted in this study, to investigate influence of long-period and long-duration earthquake motion on gravity type quay walls. Relation of residual displacement of a caisson with wave characteristics is considered, analyzing the test results and examining Newmark's rigid body sliding model.

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An unseating prevention cable is designed as the fail-safe system; therefore, it is required to be tested under various situations in order to confirm the safety of the system during and after earthquake. In this report, steel girders with unseating prevention cables were loaded in tension either parallel to or skewed with the girder and the behavior of bracket plates and webs were investigated. Test results indicated that stresses in the bracket plates were under the yield stress for both cases; showing the adequate strength for the bracket under the design load. However, in the cases for skewed loading, the web and the end stiffener were deformed due to contact with the cable, indicating the decrease in the shear strength.

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Gravestones are easy to overturn during an earthquake. Recently, many reinforcement measures have been developed to prevent gravestones from overturning. In this study, we focus attention on the reinforcement measures using interlocking reinforcement and seismic isolation system. 3-dimensional shaking table tests were done in order to investigate the seismic behavior of the gravestones with the reinforcement. Full-scale Japanese-type and European-type gravestones were tested, and seismic waves with seismic intensity of 6-, 6+ and 7 were used as input ground motions.

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