According to elastic beam theory, in this paper the energy release rate is derived and calculated without the need of a detailed analysis of the crack-tip stress and displacement fields and it is then successfully partitioned into two parts which can reflect the mode I and mode II components. The partitioning of this total value is especially significant because there is considerable ambiguity regarding the values of the energy release rate components at the tip of a crack lying along the interface between two dissimilar isotropic media. An application of the basic solution for concrete stnictures strengthened with steel or FRP plates is made to illustrate its utility.

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In this paper the authors proposed new design formulae for estimating stresses in buried pipeline with flexible joints by means of the seismic deformation method. The formulae are simpler than that applied in seismic design guidelines for buried pipeline in Japan. Empirical formulae in Guideline of Common Utility Ducts of Japan for estimating pipeline's stress during earthquake agree well with the proposed complete formulae in limited parameter region, but may give quite different results beyond the parameter region. The authors also suggested a calculation procedure to estimate the stress and deformation in buried pipeline caused by settlement due to an earthquake.

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The second phase velocity curve of Mindlin plate approaches to the extensional wave velocity of thin plate, although the second velocity of Rayleigh-Lamb frequency equation of the theory of elasticity approaches to the transverse wave velocity of continuum. This defect can be solved by introducing new elasticity moduluses and cross-sectional constants, which are treated as functions of frequency. In the same way, the discrepancy between the first phase velocity curve of Mindlin plate and that of Rayleigh-Lamb frequency equation can be solved. The governing equations of new Mindlin plate theory can be used to analyse static and dynamic problems with many kinds of structural and load systems.

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The reduction of slip strength of the multi HSFG (high-strength friction grip) bolted joints in tension is empirically known. In this study, the elasto-plastic finite displacement analysis for multi HSFG bolted joints is conducted. The analytical parameters of this study are considered the bolt row number, the bolt interval and the ratio of the design slip strength to the design yield strength, respectively. The variation of the slip strength to aforementioned parameters and the mechanism of the slip strength reduction are considered in this study. Furthermore, it does the investigation of extent of joint required to the slip strength reduction and the proposal of the strength reduction coefficient.

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Most of seismic damage estimation systems do not update their result according to the data coming one after another. Neither do they estimate functional damage caused by physical damage. In case of water supply these features are very important because continuous supply is highly required even in a disaster. On the other hand it is reported that process data was one of the most important information for measures and recovery in the Kobe earthquake. This has lead us to propose a method to estimate water suspended area making use of pressure and flow data as well as seismic information. A result of simulation and consideration about practicality are shown.

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This paper presents an experimental study on the dynamic strength and ductility of reinforced concrete bridge columns which are provided the lateral confinement with the interlocking spirals and cross ties. Three models with 900mm×400mm section and 1185mm high were constructed for the cyclic loading test. They were confined by ties (Type A specimen), ties as well as the cross ties (Type B specimen) and the interlocking ties (Type C specimen). In the Type C specimen, circular ties which were interlocked each other were used instead of the spirals. The Type B and Type C specimens failed in flexure while the Type A specimen failed in shear. The Type C specimen had superior strength and ductility to the Type B specimen. The shear strength was evaluated by comparing the design shear strength by five specifications and codes. Although some scattering was observed depending on the evaluation of strength carried by the concrete, the design shear strengthes provided in the specifications and codes were close to the experimental value.

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A new technique, based on the kinematic model for dislocation is developed for simulating ground motions caused by fault ruptures. The concerned motions are solved by the convolution scheme in time for source function and in space along rupture direction with the relevant Green function obtained by the thin layer method along depth. The Laplace transform is used for the former and the Fourier transform for the latter. Focused points in the formulation are the effects of asperity distribution, soil layering and rupture process on the transient response. The validation is made from the existing work for a Haskell rupture model in layered soil and a Kostrov model in uniform halfspace soil.

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This paper shows a new methodology of real-time prediction of liquefaction. The methodology is focused on the frequency characteristics at the liquefied ground. In practical approach, Arias Intensity, which is calculated from the observed strong ground motion records at ground surface and the soil properties of the observed point are used. By categorizing the liquefied site and the non-liquefied one of past earthquakes by soil properties and calculating Arias Intensity in every moment after occurrence of earthquake, the methodology can be applied in the real-time prediction of liquefaction. The accuracy of the proposed methodology is verified by the scenario earthquake. It is shown that the results have adequate accuracy.

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This paper shows a newly developed liquefaction monitoring system. The methodology of the detection of liquefaction at boring point based on the observed and estimated peak ground acceleration on ground surface is proposed. The neural network is applied to the proposed methodology. It seems that the accuracy of the detected results is appropriate. Further, the case study in which the objective area is Amagasaki City is conducted and the accuracy of the proposed methodology is verified. Also because of the characteristic of knowledge update in the neural network, it is possible to develop the real-time system that can feedback the information of liquefaction just after earthquake.

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Modeling phase characteristics of earthquake motion is important to synthesis a design earthquake motion compatible with the given response spectra. We used the concept of group delay time to develop a model of phase spectrum. Applying wavelet deconvolution to an earthquake motion we calculate the average value of group delay time and its standatd deviation in each compact support. Collecting earthquake motions from recent earthquake data sets a regression analysis was performed to obtain an attenuation relation of average group delay time and its standard deviation in each compact support. Assuming the normal distribution characteristic of group delay time we simulated a group delay time and then the phase spectrum by integrating it inside of each compact support.

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In this paper, we proposed a method for stochastic interpolation of bedrock ground motion amplitudes conditioned by ground motions at the free surface and/or soil amplification ratios actually observed with a priori information about these properties. The optimal estimate and estimated error variance were derived with respect to various conditions for conditional lognormal fields on the basis of conditional probability density functions for the amplification ratio and ground motion amplitude. Numerical examples were provided for various number of the conditioning sample data and various cases of cross correlation between the amplification ratio and recorded amplitude. The estimated properties were found to be successfully interpolated from the stochastic point of view.x

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There were few studies on the quantitative evaluation of ductility for concrete-filled tubular steel columns in the research field of civil engineering. The authors have already proposed a method of evaluating the bearing capacity and ductility with the results of alternate load tests under constant axial compressive force making use of concrete-filled tubular steel column models. However, it is necessary to verify the application of the proposed method to railway viaduct pillars having relatively large shear span under the influence of variable axial force. In this paper, based on the results of both above-mentioned tests and alternate load tests with large shear spans under various axial forces, ductility is revalued corresponding to damage index of concrete-filled tubular steel columns due to large-scale earthquakes.

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In this study, the deterioration of fracture toughness by effect of prestrain of 6 types of steel was investigated by CTOD tests. As a result, it came to be clear that before strain aging effect appears, the fracture toughness of most types of steels can be deteriorated by prestrain itself and that how much fracture toughness is deteriorated is differs from steel to steel. Furthermore, the influence of the direction of prestrain was found on all the types of steel but one, and so the causes of the difference between tensile prestrain and compressive prestrain were also discussed.

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Accurate prediction of earthquake response of a dam is necessary for reliable evaluation of safety of the dam. In the computation, appropriate numerical modeling should be done to get trustworthy results, and it is important to validate the modeling of dams by comparing computed results with observed ones. In this paper, the recorded response of Hitokura concrete gravity dam to the 1995 Hyougoken-Nanbu Earthquake is simulated by using a computer code developed for the three dimensional analyses of dam-foundation rock-reservoir water interaction. Extensive finite element studies are conducted, the good agreements between computed and recorded responses are obtained. Appropriate material properties of dam and foundation rock to be used in the analysis and a rational procedure to determine them are discussed.

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Spectral characteristics of strong motions and microtremors are compared at the dense strong-motion network sites in Yokohama. From strong motions, spectral ratios are evaluated by dividing Fourier amplitude spectra in the horizontal component by reference spectra which are obtained from strong motions on exposed soft rocks (SMSR). From microtremors, horizontal-to-vertical spectral ratios are obtained (HVSR). Good correlation is found between the fundamental periods of SMSRs and HVSRs especially on the condition that less site-amplification sites are excluded. Good correlation is also found between the spectral peak amplitudes of SMSRs and HVSRs (As and Ap, respectively) and the relationship is regressed as As=0.87Ap.

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In order to evaluate the building damage in the 1995 Hyogoken-Nanbu Earthquake, it is important to estimate the distribution of strong ground motion. We have estimated the ground motion distribution in Hanshin area using the recorded ground motion and building damage data compiled by Building Research Institute (BRI). However, the estimated strong motion distribution might be affected by the construction period of buildings in each district and the distribution was not estimated in some areas without enough number of buildings. Hence in this study, the ground motion distribution was re-estimated using the building damage data surveyed by Nishinomiya City, which have detailed building information. Using the re-estimated distribution, fragility curves considering detailed building information can be developed.

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A reconnaissance survey was conducted to Colombia after the 1999 Colombia Quindio Earthquake of magnitude 6.2. Outlines of earthquake and ground motion are given. The peak ground acceleration in Armenia City was relatively large in the modest earthquake of magnitude and the damage in Armenia City was hardest. The damage to buildings is described and the relation between distribution of damaged buildings and history of development of the city is investigated. The damage to lifeline facilities, especially water supply system, and its restorations are given.

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Q_S-value is evaluated from strong motion records at K-NET stations in southern Kyushu. Taking ratio among four strong motion spectra at two stations for two events, path effect is isolated from source and site effects. Q_S-value obtained in this study is one half or one third of those of previous studies. The cause of low Q_S-value may be that the wave propagation paths are shallower than those of previous studies and pass beneath the Kirishima volcanic area. The present result suggests that Q_S-value varies with depth and is very different from place to place.

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The kernel of the branch line integral of Green's function for elastic layered media is decomposed into eigenfunctions for the continuous spectrum via the concept of the Hyperfunction. The kernel of the branch line integral is due to the differences of the boundary values of Green's function in the wavenumber domain on the continuous spectrum. Therefore, the kernel of the branch line integral can be regarded to be the Hyperfunction whose definition function is Green's function in the resolvent set that is in the complex wavenumber plane. Green's function in the resolvent set satsifies the radiation condition, so that the definition and the calculation of the energy integral for the continuous spectrum can be carried out naturally. The symmetrical property of the energy integral can also be found in the formulation.

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