This paper presents a microscopic approach to visco-plastic shear deformation of fresh concrete. By using a shear box testing apparatus, the shear deformation characteristics and the effects of stress duration and compressive stress on the shear plane are experimentally investigated for glass bead assembly and fresh concrete. Then, after the occurrence probabilities of moving particles are examined for cohesionless particle assembly and adhesive particle assembly, the shear deformation behavior of cohesionless particle assembly and adhesive particle assembly is clarified. Furthermore, the mathematical expressions of shear strain and shear strain rate are induced for fresh concrete, which is considered as a kind of particle assembly containing water, adhesive particles (cement particles) and cohesionless particles (aggregate particles). And the influences of normal stress on the shear plane and stress duration on the shear behavior of fresh concrete are quantitatively discussed, and it is clarified that obtained theoretical results are consistent with the experimental ones.

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Application of photocatalyst into the building materials and components is rather newly developed technology. One of the advantageous features by applying this photocatalyst would be the capability of self-cleaning or self-desoiling on the surface of materials. This paper introduces the results of the outdoor exposure test for the various exterior finishing materials treated with photocatalyst. As relatively limited amount of data are available at present stage, the following conclusion could be made; the self-cleaning effect was recognized in the outdoor exposure test. The degree of effect was dependent upon each commercial product at present stage; however, with the photocatalyst applied products showed the significant higher self-cleaning effect compared with the ordinary products.

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This paper focuses on the effect of the clang sound from fittings, furniture, etc., on the perception of floor vibration caused by human motion. First, the psychological scale to measure the vibration and sound is constructed by the sensory test. Second, the physical value representing the psychological scale is introduced on the basis of the measurement of the vibration and sound. The relationship between the psychological scale and the physical value reveals that the loudness of the sound affects the perception of the vibration. Finally, the evaluation index of the perception of the vibration influenced by the sound is proposed.

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The influence of the uplift of building base on an earthquake response is studied by the viewpoint of energy. Dynamic response analyses using both a single-degree-of-freedom system and a frame model with of an eight-story building are executed. The difference of the input energy to a model between the uplift restraint model and the uplift free model is examined. As a result, the following conclusions are obtained. 1) The total input energy of the uplift free model tends to be smaller than that of uplift restrained model. 2) Even if the total input energy of the uplift free model is larger than that of uplift restrained model, the maximum strain energy becomes smaller than that. 3) The energy reduction effect by the basement uplift is also testified by the frame model analysis.

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Research development on the estimation of dynamic characteristics of multi-storied buildings considering soil-structure interaction have been made based mostly on either earthquake response observations or forced vibration experiments with very little on microtremor measurements. Stable parameter identifications using microtremor measurements are considered to be difficult, because the elastic deformation is insufficiently developed for low rise buildings. An identification method is proposed in order to estimate the dynamic characteristics of multi-storied buildings separately from the soil characteristics using the sway and rocking model. The proposed method was successfully applied on the estimation of dynamic characteristics, as well as the sway and rocking parameters of ten different buildings. Results were consistently stable, and the applicablity of the method was confirmed.

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High-rigidity and heavy buildings such as reactor buildings usually have large soil-structure interaction effect in its dynamic response. In such cases, spectrum ratio of the top of the building to the bottom for horizontal motion gives different result from the dynamic characteristics of the building under fixed-base condition because the effect of the rocking motion of the base is not eliminated. This paper presented a new method for such problems; applied it to a ground blast vibration, microtremors and forced vibration test results; and transfer functions of the building for fixed-base condition were obtained. The proposed method can be applied when the exciter is set at the upper part of the buildings.

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The characteristics of piezoelectric dampers built with piezoelectric materials are investigated for the basic study of smart structural system for building structures. Piezoelectric materials can be applied not only to the sensors and the actuators, but also to the dampers. The damping mechanism and the stiffness derived from the piezoelectric equation are presented in this paper. In order to verify a damping characteristics of these devices under low frequency vibration, free vibration tests and calculations are carried out with a steel cantilever (119x65x6mm, f_1=3.7Hz). The damping system attached to the bar consists of a resistor, an inductor and 8 pieces of piezoceramics(60x60x1.5mm) at the end of the bar. The conclusion remarks the followings, 1)The analytical calculations for the piezoelectric damper under low frequency vibration correspond with experimental results, 2)The damping behavior of piezoelectric materials can be obtained by considering the shunted circuit, and 3)The damping factor of a structure with a piezoelectric damper can be calculated taking into consideration all the structural energy dissipation ratio, including the contribution of the piezoelectric materials.

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This article presents the domain reduction method, a two-step finite element methodology for modeling earthquake ground motion in highly heterogeneous localized regions, and its application to hill topography. Four hill models, considering a surface weathered soft layer and layered system under the hill, are excited by a point source and plane waves. The amplification of seismic ground motion on and around 3-dimensional hills are compared to those of 2-dimensional hills and simple 1-dimensional amplification. The complicated pattern of amplification generated by collaboration of hill topography with layers are illustrated and quantified. The peak values and peak frequencies of amplification factor around the top of 3-D hills are larger than those of 2-D hills and 1-D amplification. It suggests that 1-D approximation of subsurface structure under a hill is inadequate when 3-D effect is significant.

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The objective of this paper is to clarify the maximum control capacity of the Maxwell-type semi-active damper to develop an effective system for structural control. We focus on the force-displacement orbit to understand and consider the physical constraint inherently associated with the Maxwell model. The key conclusions are as follows: 1) A semi-actively controlled damper can realize twice as much damping augmentation as a passive damper. 2) A simple on/off control scheme is the best strategy for energy dissipation or displacement reduction. 3) There is an optimum control parameter that minimizes the acceleration or the story shear force, and this parameter can be directly obtained in accordance with the system stiffness condition.

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In the present paper, the failure behavior of the joint between fiber reinforced polymer (FRP) shapes and polytetrafluoroethylene (PTFE) roof membranes has been studied. The tensile test of the joint has been performed statically, then its failure mechanism has been discussed. The fiber Bragg grating sensors have been embedded into FRP materials. It has been successful in that not only strain quantities but also optical power spectra were measured in detail. Consequently it is shown that the optical power decreases as the load increases and its shape develops two peaks after reaching at a critical load due to the occurrences of small transverse cracks.

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The present paper discusses not only a linear buckling axial force but also an elasto-plastic buckling axial force for cylindrical latticed shells composed of diagonal and horizontal members. The cylindrical latticed shells are assumed under axial compression, which yields large axial forces to horizontal members. The discussion focuses mainly on the buckling behavior of horizontal members. First, the linear buckling force is derived using continuum analogy and the parameters affecting to the buckling behavior are analyzed. The analysis has shown that the subtended half angle of the members and the member slenderness dominantly affect to the linear buckling force. Second, the elasto-plastic buckling force for the horizontal members is expressed in terms of generalized slenderness which includes the buckling characteristics as continuum shell.

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The present paper proposes a method for designing member sections in a two-way grid shell of single layer against a specified ultimate buckling load. The method is applicable for not only uniform but also unbalanced load. To consider significant bending effects explicitly, a strength formula for beam-columns that is given in the LSD recommendation of All is adopted as the design formula. Moreover, to cope with the significant geometric nonlinear behavior, elastic nonlinear FEM analysis, which becomes easily available today, is applied as the principal tool for the method. The procedure is composed of three principal job steps. First, to obtain the generalized slendemess, the preliminary elastic buckling analysis is performed in which the section of each member in an analyzed model is given proportionally to its axial force. Second, the stress analysis in which the section rigidities in the model are assumed to prevent the excessive geometric nonlinear effect at the design point is performed. Finally, the member sections are determined based on both the generalized slendemess and design stresses applying the ultimate strength formula for beam-columns.

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This paper addresses the shape optimization problem of the maximization of critical load of space structures with given volume. The problem is dealt with as the nonlinear programming problem. It is difficult to directly maximize the non-linear buckling load factor as the objective function because of the large calculated amount and the possible coincidence of several critical points on optimal solution. On the other hand, evaluated as linear eigenvalue problem, the buckling load may not be appropriate since the prebuckling deformation is disregarded. In this paper, to take account of the effect of prebuckling deformation, the buckling load is estimated by performing linear eigenvalue analysis on an equilibrium point with specified deformation. The proposed scheme and its sensitivity analysis method are described. An arch and a two-way grid shell are shown as numerical examples, the effectivity of the present method is confirmed through these examples, and the structural characteristics of the result are also discussed.

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Monotonic loading test were conducted on four reinforced concrete short beams in order to investigate the shear transfer mechanism due to arch action. The test variables included the amount of web reinforcement and bond performance of longitudinal reinforcement (i. e. bond or no bond). The conclusions obtained from this investigation were as follows. 1) All the test beams failed due to abrupt propagation of diagonal tension crack. 2) Linear strain distribution was observed in the concrete of unbonded test beams. This result implies that the arch action does not exist in unbonded beams, which is contradicted to the theorem on arch action.

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The authors of this paper have been developing a new seismic element, which is composed of a concrete filled steel tubular short column with diagonally arranged re-bars and spandrel girders. In order to establish a simplified evaluation method of seismic capacity of R/C building structures with the seismic elements, the maximum responses obtained from time history earthquake response analysis using equivalent single-degree-of-freedom (SDOF) modeling are compared with those from multi-degree-of-freedom (MODF) modeling. Moreover, the effectiveness of equivalent linear method for predicting the maximum response of equivalent SDOF model is investigated.

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After the 1995 Hanshin-Awaji Earthquake, many researchers have energetically studied on the seismic behaviors of strengthened R/C columns by CFRP (Carbon Fiber Reinforced Plastics) sheet jacketing. Design equations for the strengthening of R/C columns using CFRP sheets were proposed on the basis of the above studies. However ductility improvement of horizontally excited R/C columns under high axial load could not be evaluated by these design equations. In this paper, the author proposes the evaluation method ofductility improving effect of CFRP sheet jacketing and steel plate jacketing on the basis of experimental studies. From these experiments, it has been clarified that the steel plate jacketing is more effective to improve the ductility of horizontally excited R/C columns under high axial load.

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The present authors had proposed the K-braced frame with shear resistance member made of ordinary steel as a hysteretic damper. In this paper, for convenience of seismic design of the braced frame with the damper, the strength evaluation expression for the shear resistance member is proposed. This expression is based on limit analysis theorem for continuous media using the assumed rigid-plastic deformation fields. Also, elasto-plastic finite element analyses are performed on various kinds of shear resistance member under monotonic and cyclic loading in order to investigate the optimum shape of shear resistance member, in which the equivalent plastic strain is adopted as the index of damage concentration. These results show that 1) the present strength evaluation expression has good accuracy and validity compared with finite element analyses results. 2) the optimum shape of shear resistance member, which minimize the equivalent plastic strain, are clarified.

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Photographs and video movies are useful media for recording architectural spaces. However, those media can record basically 2D images and they are not enough to represent 3D architectural spaces. Therefore, we have developed a pseudo-3D photo association system for creating new style architectural archives on the Web. This system is called STAMP (Spatio-Temporal Association with Multiple Photographs), which allows people to create and publish pseudo-SD architectural archives by easy operations. In this paper, we discuss basic methods for creating and analyzing-architectural archives by using this system.

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