As a model investigation for the development of lightweight polyester concretes with high strength, lightweight polyester mortars using unsaturated polyester resin and lightweight aggregates are prepared with various mix proportions, and tested for slump, working life, apparent specific gravity, flexural and compressive strengths. As a result, their slump and working life can be controlled, and their flexural and compressive strengths are 9.7 to 22.0 Mpa and 23.0 to 100.8 Mpa respectively at apparent specific gravities of 0.86 to 1.73. Equations for predicting their compressive strength are proposed for different aggregates.

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The influence of coarse aggregate on the fracture toughness of high strength concrete was investigated. Fracture parameters for concrete were analyzed based on the poly-linear approximation analysis of the tension softening diagram with the data of a load-load point displacement curve. Three-point bending tests on the pre-notched aggregate beam specimens and the pre-notched concrete beam specimens were performed. Toughness modulus (T.M.) was considered to be an appropriate parameter to evaluate the effect of microcracking on the toughness of various concretes. The fracture energy of aggregate was relative to the tensile strength of aggregate. In concrete with the high strength mortar matrix, failure was initiated by aggregate cracking and the fracture energy of concrete was strongly affected by the fracture energy of aggregate. The crack resistance of high strength concrete depended on the fracture properties of aggregates and significantly varied from the types of aggregates.

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This paper presents the method to apply excitation and perception apparatus to floors covered with finishing materials. The apparatus had been developed by the author for evaluating floor vibrations caused by human walking. At first, vertical loads applied to floors by walking people and the apparatus, and floor vibrations caused by walking, were measured and compared by using some finishing materials. Secondly, from the result of the measurement and the comparison, it has been shown that the vibrations were hardly influenced by finishing materials. As a result, the method of measuring floor vibrations directly after removing finishing materials from floors, was established for the measurement method of vibrations of floors covered with finishing materials.

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This paper presents the relative evaluation methods on slipperiness of stairway treads from a viewpoint of safety of the aged. First, sensory tests with the aged (upper 60 years old) and young persons (20 to 59 years old) were carried out, to make evaluation scales of slipperiness. Next, it was cleared that C. S. R・S which was the physical value of slipperiness of stairway treads made in the past studies corresponded to each evaluation scale, also the correspondence was enough as the evaluation indexes. Finally, the evaluation indexes and the measuring method of C. S. R・S were presented as relative evaluation methods.

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A generation method of the input wave which causes the largest response to SDOF with origine-oriented hystereses is proposed. A uni-sinusoidal wave is selected to examine the phase effect on the inelastic response as a basic case , then it can be proved that the response becomes largest when the phase is selected properly at the time of the reverse point of the response displacement and this phase property can be applied to cases when the frequency is varied during the motion. Finally a critical wave with the Kanai-Tajimi power spectrum is generated as an example and its responses are compared with those with randam phases and those with phase properties specified in narrow frequency bands.

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This paper proposes a dynamic analysis method using a vibration equation of the single-mass system for structures receiving earthquake. The effect and the usage of the proposed method were testfied. The theoretical correctness was also examined by using an analysis example for the multi-mass system. Consequently, it was proved that this method has superior characteristics. An examination using a non-linear analysis example was carried out. At the result, it was con-firmed that the applicability of the proposed method for the non-linear analysis is of high grade.

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This paper discusses the spatial correlation structure of earthquake ground motion in a small field across a distance of the order of structures. The data from Chiba Array is analysed to obtain the empirical correlation coefficients, which present nonstationarity. For a small field, where the wave propagation effect can be negligible, the main shock or an impulsive motion tends to cause higher correlation than the coda part The vertical motion shows difference in coherency depending on the earthquake characterizing parameters, while the horizontal component reflects predominancy of the local soil effect

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The most convenient method to identify the dynamic characteristics such as natural periods and damping ratios of structures is to utilize the record of microtremor. Then, the method to identify them by the wavelet transforming the input and output of microtremor for a structure is presented. Using a white noise as the input of microtremor, the natural period and damping ratio of single degree of freedom system are identified. The dynamic characteristics will be changed by the reduction of stiffness of structural member during strong ground motions. These reductions of stiffness are related to the damage rate of structural members by earthquake and it is assumed that these reductions of stiffness during strong ground motion cause the abnormal signals in their responses. Then, the method of detecting these abnormal signal is proposed by utilizing the wavelet transform of the responses of structures.

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A theoretical correlation model is presented for spatially varying earthquake ground motion with the concept of a composite random process. It seeks to explain the fractal nature of the correlation structure contributed by the effects of the source, path of waves and the local site. The correlation model shows self-similarity in the logarithmic decay form with increasing distance. SMART-1 array data is used to verify the applicability of our model. The "apparent" correlation detected for the local average processes is realized as the "true" correlation incorporating the spatially averaged spectral density function.

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The dynamic characteristics of soil-structure interaction (SSI) in irregularly layered soil are investigated to clarify their effect on the response of embedded structure. Impedance functions and foundation input motions as well as the response of a building embedded in a cylindrical sedimentary basin are calculated using axisymmetric hyperelements, considering the rigidity of the structure's footing, which enhances computational efficiency especially in large-scale soil models. Evaluation of the foundation input motion in irregularly layered soil is found to be essential to assessing the structural response characteristics. Results of response analyses suggest that surface waves induced at the edge of the basin may impinge on the embedded structure and amplify its response.

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An earthquake observation station with two vertical instrument arrays has been established to investigate the amplification characteristics of surface layers at the site of the Kushiro Local Meteorological Observatory, where a peak ground acceleration over 900cm/s^2 was observed in the 1993 Kushiro-Oki Earthquake. So far, many observed records from weak motions to strong motions have been accumulated, including the 1994 Hokkaido Toho-Oki Earthquake. The present paper reports the earthquake observation system and main observed records and examines the amplification characteristics of surface layers for weak and strong motions to clarify the topographical and non-linearity effects on earthquake motions, using observed records.

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A method for rational estimating the local soil effects on the seismic force of a structure is investigated based on reinforced concrete (RC) buildings in Fukuoka city. The array microtremor measurements both on ground surface and structure have been carried out about 180 RC buildings in Fukuoka From the separation of predominant period of ambient vibrations into soil effect or building effect, both natural fundamental vibration period of the building (T_b) and that of surface ground (T_g) can be estimated exactly. There are three cases in vibration mode of building and surface ground; (1)T_b>T_g, (2)T_b≒T_g, and (3)T_b<T_g. The transfer functions and the coherence functions, which are calculated statistically between ambient vibrations of building and that of surface ground, are used for evaluating vibration types. In order to evaluate the magnification of surface ground, two dimensional analyses have been carried out using the boundary element method After estimating the magnification of the structure including the local soil effects, the buildings of T_b≒T_g are subject to the largest response.

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Field observations on overturning of tombstones during the Hyogo-ken Nanbu Earthquake was performed in and around Kobe City. The relation of geomorphological condition and geomorphometric measures (elevation and gradient) with the overturning rate of tombstones was examined quantitatively, and the empirical equations between the gradient and the overturning rate were proposed for each geomorphological condition. The distribution of the overturning rate in the disastrous area was estimated by the equations together with the geomorphological map. The distribution of the overturning rate was transformed into the distribution of peak ground velocity by using the relation derived from the observed peak ground velocity and the overturning rate of tombstones.

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We propose new analytical model for the hysteresis restoring force characteristics of rubber bearing for base isolation system and a new analytical method of hysteresis system using the restoring force model of power function type for vibration response. This model can express the restoring force characteristics of hardening and softening type depending on amplitude of horizontal displacement, frequency and surface pressure. First we calculated the nonlinear vibration properties (damping, stiffness) of rubber bearing using this model, then we analyzed the dynamic vibration response reflected in the vibration properties. We examined the appropriateness of this method as a result of analyzing the vibration response of practical rubber bearing for a bridge.

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The first-order intervening variable method for the stochastic estimation of the seismic response of the indeterminate ground is presented. This method is based on the Taylor expansion as to the intervening variables which are the functions of the stochastic variables. This method enables to deal with the problem where the nonlinearity of variation of response as to the variation of stochastic variables is remarkable without the loss of the simplicity. The power-function, quadratic-function, and spline-function are employed as the intervening functions. The Monte Carlo Simulation of one-dimensional soil column are carried out to demonstrate the effectiveness of the presenting method.

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A member model that was divided into sub-elements along the member axis and had fibers at these ends, was developed for the combined non-linear analysis. The fibers have the stress-strain relationship of a developed Ramberg-Osgood model. To assume appropriate stiffness, a modified trial method was used. Moreover, large analytical increment for an overall frame was set for the application to a frame with many members. Overall analytical results for a simple truss agreed well with experimental results. In this analysis, one lattice showed so complicated behavior that contained a little first buckling, unloading, and final buckling in another mode.

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A new numerical method is presented for finding symmetry limit of planar frames subjected to cyclic horizontal deflection under vertical dead loads, and the symmetry limit analysis is carried out for a two-story-one-bay frame. Through the analysis, following facts are revealed: (1) A particular deflection mode appears or grows cycle by cycle if the amplitude of the cyclic deflection is above the symmetry limit. (2) In most cases, the amplitude of the deflection at symmetry limit is less than the magnitude of deflection at stability limit under monotonically increasing horizontal load.

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In order to investigate the seismic behavior of frames strengthened by various methods and the effect of strengthening methods for existing reinforced concrete buildings, 39 specimens were tested. From the results of experiment, the effects of strengthening methods on the strength and displacement performance were confirmed as compared with reinforced concrete frames. These specimens were analyzed by means of elasto-plastic frame models and compared with the test results on the positive envelope curve, the stiffness, and failure mode under seismic load. The analytical results in the ultimate strength and elasto-plastic stiffness of the specimens gave a good agreement with the these test results.

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The shear strength and shear failure phenomena were investigated for the square hollow slabs with partial lateral restraint at all edges. The experiments were done by testing three series of the slabs which had been shear-reinforced by H shaped steel and ring shaped steel. The test results concerning to shear strength and failure phenomena were discussed with the analizing results for an equivalent cross beam structure model. The load-deflection relationship was also discussed with the flexural analizing results with consideration to compressive membrane actions.

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A measurement setup, that is based on the structured light projection method, is developed to obtain a 3-dimensional image of the concrete crack surface. And then authors construct the 2-dimensional analytical method of shape properties from it's 3-dimensional image. Analyzing a measured crack surface by tensioning, some functions are formulated. From the analytical results, the measure sensitivity is about 0.125 millimeter/dot and the sampling interval length is about every millimeters, those were able to show the tendency of the shape properties of the concrete crack surface by tensioning.

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In this paper, the authors present a new arrangement of reinforcing bars to improve the ductility in RC base-story exterior columns the axial load to which severely changes during an earthquake. The new method is to arrange more amount of reinforcement eccentrically so that it works as compression steel when the axial load increases. Consequently it is expected that the compressive stress of the concrete is reduced, and the compressive failure of the concrete is greatly delayed. The effectiveness of this method is confirmed through an analytical and empirical investigation.

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Base shear coefficients CB related to seismic design loads, necessary for advanced ultimate strength design method of prestressed concrete structures, were investigated through dynamic response analyses on typical model structures with 1 thru. 12 stories. The analyses were carried out using lumped mass systems of model structures, based on elastic characteristics and before/after yielding ones of stories under the standard five earthquake waves. Relations between CB and the first natural period T of structures were introduced from the maximum response base shear coefficients and story drift angles, which were obtained on condition that stories of structures were limited to be in elastic state and yielding of stories were allowed, for the expected earthquake levels.

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In respect to the composite beam-column which is made of H-shaped steel and concrete placed between upper and lower flange of the steel, the followings have been comprehended from experimental results on its plastic mechanical behavior and its hystresis characteristics against cyclic increasing bending moment under applying of constant axial force. 1.Concrete-crash does not reduce stiffening effect by concrete which is recognized in plastic mechanical behavior and hysteresis characteristics ; however, concrete does not almost bear the applying load after it is crushed. 2.In case of that the parameter a(=√<(t_f/b)(t_w/d)> is larger, state of flange in the tensile side becomes to be more remarkably inelastic. 3.Plastic deformation capacity is evaluated by the parameter α, which can be also quantitatively estimated in the safety side by the proposed equation.

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For developing the high strength bolts, for example, F15T bolt set which tensile stress is about 150Kgf/mm^2 (about 1.5GPa) and higher than that of the conventional strength bolt, the problem on delayed fracture must be solved. And it is evident from the past studies that the delayed fracture is concerned with the diffusible hydrogen in steel. In this paper, firstly from considering the past studies, the practical and easy method of the accelerated tests in which the diffusible hydrogen concentration is used for estimating the sensibility of the high strength bolts to the delayed fracture is proposed. And the results of this proposal accelerated tests on three types steels for high strength bolts are reported herein. From the consideration of these results, it is made up clear that the critical diffusible hydrogen concentration which is obtained by the proposal method can adequately estimate the sensibility of high strength bolt steels to the delayed fracture. Secondaly the results of this accelerated tests on four different notch shaped specimens are reported. And the influence of the notch shape on the critical diffusible hydrogen concentration in proposal method is discussed. Lastly the results of these tests on ten types specimens made from ten different F10T bolts set lots are reported. The F10T bolt set is the most popular and conventional high strength bolt in Japan. So from the consideration of these results of F10T bolts, the requirement on the critical diffusible hydrogen concentration for developing the F15T bolts sets is obtained.

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This system truss has the mechanism to induce the high bolt clamping force. Thus, the initial clamping force reduces the stress range in the bolt under applied loads and so improves the fatigue life. To clarify the fatigue properties of space trusses under cyclic loads, this paper reports the fatigue tests of bolt joints conducted on actual connection models. The test variables are the bolt size, the level of initial clamping force and the stress ratio. And, for practical applications, the results are presented in the S-N diagrams described by the maximum stress and the stress range.

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The strength and ductility of new SRC columns using small size steel, high strength concrete and hoops is discussed. Comparing with the RC columns, effect of small size steel is clearly exhibited for improving shear strength and ductility in both strong and weak loading axes. Effect of hoop reinforcement and of the separation of concrete section when loaded in the weak axis are discussed. The analytical method for shear and flexural strength, and for ductility of the SRC columns is proposed. The analytical results agreed well with the test results.

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With seventy percent of its area composed of mountains and hills, Japan has many hillside cities. The risk assessment of such hillside cities for seismic vulnerability has to be made from many more viewpoints than that for flat-land cities. For instance, severe ground quakes on hills, slope landslides and difficulties in evacuation are to be taken into account. So, this present paper is focused on the construction and use of a GIS database with its various parameters regarding hillside cities. The paper attempts to assess risks of slope failure, liquefaction and site effects and overlay the risk data on information about the distribution of housing, public facilities, and population, among others. The paper thereby seeks to evaluate the vulnerability of slope cities to earthquakes.

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The purpose of this paper is to calcurate imcompressible viscous flows with free surfaces by using the third-order upwind finite element scheme and the Arbitrary Lagrangian-Eulerian (ALE) method. Waves on the free surfaces are limited to the waves without braking conditions. Numerical dissipation added into the upwind finite element scheme is expressed by the fourth-differentials with respect to the flow velocities. The pressure is computed by the Poisson equation which is derived by making the divergence of the Navier-tokes equations. Numerical results of flows with free surfaces are presented to illustrate the effectiveness and robustness of the proposed upwind scheme.

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Basic questions are presented on the applicability of the proposed method of seismic damage estimation of building structures by means of wavelet analyses. Major points are as follows: 1)The applicability of the method was examined only for the by-linear type hysteresis curves having a sharp change from the elastic region to the inelastic region, but since an actual structure has a smooth transition from linearity to non-linearity, the proposed method seems to be useless in spite of the authors's desire; 2)The damage estimation was based on the Miner's fatigue law, but since the cracks generated in several cycles of plastic strains are not fatigue cracks but ductile ones, the conventional linear estimation of cumulative damage may not be applied for earthquake damage.

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The authors thank Dr. Hitoshi Kuwamura for his discussion and the answers are as follows. (1) The absolute acceleration response of a SDOF structure with Wen type hysteretic restoring force model having a smoothen hysteresis curve is analyzed using wavelet analysis. From this simulation, it is clear that the proposed method can be used to estimate the point changing from elastic region to plastic region for a structure having a smooth hysteresis curve. (2) In this study, the damage generated in several cycles is assumed to be the low-cycle fatigue by referring the papers. It is considered that Miner's fatigue law can be applied for this cumulative damage.

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