In this paper, we examined the effect of rupture starting point uncertainty on the long period ground motion prediction of Tokai Earthquake. Monte Carlo simulation with sample size 30,000, assumed that the rupture starting point is uniformly distributed on the fault, was performed, and the statistics of the ground motion were calculated.The results of numerical simulations showed that the maximum value of the velocity response spectrum in a long period range could be well expressed by the type III extreme value distribution, and we pointed out that it may have an upper limit in this statistical distribution by using extreme value statistics theory.

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Nonlinear static procedures (NSPs) are widely used for the seismic displacement prediction of existing buildings. These procedures have become increasingly important with the emergence of performance-based engineering as a technique for seismic evaluation and design where the expected performance is better correlated to displacement response. This paper presents an evaluation study of current NSPs for seismic performance assessment of masonry buildings. The evaluation is conducted through comparison of displacement predictions from current NSPs with the values recorded from shake table tests of a masonry building model. The investigated NSPs are: the improved Displacement Coefficient Method (DCM) defined in FEMA440 and implemented in the ASCE-41 and the improved Capacity Spectrum Method defined in FEMA-440. The predicted displacements are used for probabilistic damage assessment using fragility curves that describes the probability of being or exceeding a specific damage state given displacement response. The results showed that NSPs predicted high probability of extensive damage state which is in good agreement with the observed damage from testing. This paper also presents a discussion of the sources of variability in the predicted displacement and damage prediction using the investigated NSPs and emphasis the importance of the consideration of uncertainties in seismic performance assessment using fragility curves.

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Steel structures had experienced a big response for a long time caused by the great earthquake motion during the Off Pacific Coast Tohoku Earthquake. Lots of non-structural damages and many videos shot in many places are the characteristics of this earthquake. Some opened earthquake records and videos are used in this study in order to investigate the earthquake response of the steel structures. An application of vision-based method has been carried out on a video shot by Japan Broadcasting Corporation (Nippon Housou Kyoukai) of high-rise buildings at Shinjuku, Tokyo during Off Pacific Coast Tohoku Earthquake on 11th March 2011.

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The Great East Japan Earthquake brought serious damage in the wide area, and caused a shortage of gasoline supply indispensable to the restoration from disasters. In this research, the cause and bottleneck of the problems are solved by applying the method of system dynamics. The same procedure can be applied to the Nankai Trough Earthquake which is expected to occur in near future and to have the same problems.

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The characteristics and usage of the non-dimensional damping coefficient Co have been studied in this paper. It's made possible to estimate the damping performance regardless of the specification by using the parameter Co.Because the parameter Co is dimensionless, the specification of the structure is irrelevant to estimate. The vibration test using structure models and the numerical simulations were carried out under different kinds of conditions. The theoretical verification was carried out using the results for the characteristics of the parameter Co. At the result, the following was revealed.1) The universal relational expression is established between the Co and response reduction ratio. Despite changes in the size and structural specification, not affected, this relational expression is true universally.2) The universal relationship is established between the dynamic parameter M, K, C and Co. As an example, consider the two structures of different sizes and structural specifications. By using this equation, it’s possible to adjust the damping characteristics will be the same as that between the two structures. The method has been shown in this paper.

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Site amplification factors are empirically evaluated as ratios of ground motion amplitude recorded at nearby station pairs. The factors decrease when pseudo efficient strain evaluated by 30m shear wave velocity and peak ground velocity exceeds 0.0003 and they in the periods range 0.15 to 0.2 seconds decrease more significantly than other periods. We develop empirical models to estimate nonlinear site amplification factor for 5% damped response spectral acceleration, peak ground acceleration and velocity. These proposed models show consistency with existing methods.

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In this study, we propose a procedure for constructing seismic vulnerability functions for each railway structural type based on case histories of railway structures damaged by past earthquakes. Railway structures are classified into 5 types as follows: 'Natural ground and lower embankments', 'Embankments', 'Cuttings', 'Bridges',and 'Tunnels'. A method to measure the total length of each structural type is examined. A method to know latitude and longitude of each point on railway line is examined. A procedure to compiling damage survey data of railway structures is also examined. Damage rates of each structural type at each seismic intensity level in the 2004 Niigata-ken Chuetsu Earthquake and in the 2007 Niigata-ken Chuetsu-Oki Earthquake are calculated. The results indicate that (1) the lowest seismic intensity levels which cause damage are different by each structural type, (2) damage rates at each seismic intensity level are also different by each structural type, (3) ‘Embankments' is most vulnerable in any structural types.

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Seismic base isolation effect in a liquefied sand layer was investigated in terms of energy transmission based on soil properties measured in a series of undrained cyclic triaxial tests. Transmission of seismic wave energy in a soil model consisting of a liquefied surface layer and an underlying non-liquefied layer was calculated, considering liquefaction-induced changes in S-wave velocity and internal damping. Among two different base-isolation mechanisms, it was found that drastic increase of wave attenuation in a liquefied layer due to shortening wave length gives a greater impact on the base isolation than abrupt change of seismic impedance between the liquefied and non-liquefied layer with increasing thickness of the liquefied layer. Also indicated was that cyclic mobility characteristics mobilized in dilative sand containing little fines tends to reduce the seismic isolation effect to a minor extent.

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Use of earthquake motion indices, which have been used to evaluate earthquake damage, is proposed in order to improve the evaluation of accuracy of the seismic response analysis of ground. Seven indices, PGA, PGV, spectral intensity, instrumental seismic intensity, power spectral intensity, predominant period and maximum shear strain, are used as earthquake motion indices. In order to prove the effectiveness of the method and to evaluate the applicability of various methods, two vertical array records are analyzed by the equivalent linear, total stress truly nonlinear and effective stress analyses and compared. The effective stress analysis showed best simulation, but other methods are also good depending on the index. It is shown that proposed method is useful to see the error or accuracy from various points of view. Then, parametric analyses are made by using scaled input earthquake motions. The results clearly indicate that the compatible strain ranges for equivalent linear and total stress truly nonlinear analyses depend on the purpose of the analysis.

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In Midorigaoka, a residential area in Shiroishi City, a fill slope was damaged by the 1978 off Miyagi Prefecture Earthquake (Mj7.4) and the 2011 off the Pacific coast of Tohoku Earthquake (Mw9.0), while it was not damaged by the 2005 off Miyagi Prefecture Earthquake (Mj7.2). To better understand the mechanism of the damage, it is necessary to have a better understanding on the seismic response of the fill slope during not only the 1978 and 2011 events but also the 2005 event with high accuracy by taking into account site effects. In this study, we evaluated the seismic waveforms at the shoulder and the toe of the fill slope based on moderate earthquake observation records. Furthermore, based on the estimated waveforms, we discussed the threshold ground motion which influences the seismic damages of the fill slope. The estimated waveforms and related discussion will be useful in future study of seismic performance of fill slope in residential areas.

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