This paper deals with the effects of sorts and contents of impurities in recycled coarse aggregate on the properties of recycled concrete. Recycled aggregate which was assumed producing from reinforced concrete structure of wall, floor and roof slub with several sorts of finishing materials. The sorts of finishing materials for original concrete were a multi-layer wall coating (ML), a synthetic resin emulsion paint (EP), a gypsum plaster (GP), a lime plaster (LP), a fibrous wall coating (FW), a ceramic tile (CT), a plastic tile (PT) and an asphalt membren water proofing (AM). The items of the investigations were on the compressive strength, static modulus of elastisity and drying shringkage of the recycled coarse aggregate concrete.

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This paper describes preliminary surveys and fundamental experiments for the development of concrete floor slab finishing robot. The auther discusses the unique development procedure and notes the importance of setting proper development target. An analysis of working hours is presented as an example of one such survey, together with details on robot task allocation and function setting. Data for robot design was obtained from experiments on the selection of finishing tools suitable for robot, and on the dimensions and weight of locomotion equipment capable of traveling over green concrete.

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This paper presents the progress and the result of the development of "Impactive Excitaion Apparatus" based on vertical loads applied to floors while walking, to establish the appropriate measurement method of floor vibrations caused by walking. "Impactive Excitation Apparatus" is composed of a dropping weight and a rubber sheet, and it can reproduce floor vibrations caused by heel contact while walking. And we verify the appropriateness of a method to compute the duration of vibrations Th, which influences the human sense of vibrations, from the results measured by "Impactive Excitation Apparatus" and "Perception Apparatus" which was established in previous paper.

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In this paper, the groth and decay of chromosomes in the process of intelligent GA search is examined using schema theorem of GA and the influences of the probability of crossover and mutation on the evolution process are discussed through a specific computational example. It is found that the problems not only in deciding the length of chromosomes but also in selecting the probability of crossover and mutation can be effectively improved. Based on the examinations above, the application of the intelligent GA to some structural reliability problems is investigated and it is shown that the intelligent GA is applicable to general structural reliability problems through some computational examples.

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This paper describes a theoretical study concerning dynamic behavior of porous elastic solid and pore water in alluvial media. The dynamical characteristics of a poroelastic half space are investigated using a model based on theory of aggregate body. There are some permeability ranges which are unable to be qualitatively explained by behaviors of perfectly elastic body simulated by using the characteristics of the body waves traveling in the aggregate body.

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A procedure for evaluating the number of injuries in an office room is presented. The procedure is based on observations that most of injuries at indoor are caused by overturning of furniture. Using the procedure combined with the GIS data of the area of interest, the number of injuries in office buildings in the central part of Kawasaki city, Japan is evaluated for a hypothetical earthquake. The results show that earthquake injuries in urban office environment could be enormous and should be considered in disaster mitigaion planning.

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Two simple methods for evaluating group-factors of pile foundation are proposed in this paper. These methods are based on parametric study using thin layer formulation. First method is to evaluate the group-factors of a large number of piles from those of a small number of piles. This method is derived from the characteristics that the group-factors are represented by the power function of the number of piles. Second method is to utilize the design equations of the group-factors for homogeneous and two layers soil. These equations are based on the distinct relationships between the group-factors and interaction factors. These two methods correspond well with the thin layer formulation.

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It is very important to estimate the cumulative damage of buildings by a strong ground motion quantitatively, because it is necessary to judge whether they are able to be used or not in future. Even after they are judged to be able to be used, it is also necessary to judge the amount or method of reinforcing them. In this paper, the estimation of cumulative damage of building with hysteretic restoring force by using wavelet analysis to strong response motion is proposed. Firstly, it was assumed that the abnormal signals might be contained in the observed acceleration records, which should be produced at the point changing from elastic limit to plastic limit and might be detected by wavelet analysis. Through the numerical evaluation using the model, it is proved that this assumption is correct and it is confirmed thatjPthe wavelet analysis will be used to estimate the cumulative damage of buildings by earthquake, effectively.

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The purpose of this paper is to predict reduction effects on required strength of multi-mass system subjected to earthquake. There supose that plastic deformations occur in the first story, and that efficiencies of nonstructural members can be equivalently substituted to a linear elasticity and a viscous damping. Considering a probability distribution of equivalent period that is based on a probability distribution of input energy per unit time, and that an input energy variance depend on equivalent viscous damping, it is recognized that predicted values nearly agree with simulation values. Succeedingly, the reduction ratio on required strength based on this method, and their factors are shown.

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The site amplification characteristics of ground motion at Kushiro J. M. A. site are investigated. The transfer function of surface layer to bedrock calculated from the seismic observation array data shows no pointed peaks, no clear dips, higher amplification in high frequency. This real phenomena can not be simulated with the homogeneous multi-layered model subjected to incident plane waves. This paper presents that the stochastic simulation using two dimensional finite element model taking account of the effects of the spatial variability of soil properties, spatial coherency of incident waves, and topographical condition. The results of stochastic simulation of transfer function is good coincident with that of the observation data.

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A numerical method is presented for computing ground surface displacement induced by a vertical point force acting on a three-dimensional layered elastic half-space. The contribution of the residue of the Rayleigh poles and the branch line integrals, i.e., that of Rayleigh and body waves, to the ground displacement is computed for a two-layered medium, and its variation with the S-wave velocity ratio between the surface and base layers, V_<S2>/V_<S1>, is examined. It is shown that, when V_<S2>/V_<S1> is less than 1.5 or when V_<S2>/V_<S1> is greater than 1.5 and the normalized frequency is not close to 1, Rayleigh waves get to dominate as the normalized ditance is greater than at most 3〜4. When V_<S2>/V_<S1> is greater than 3 and the normalized frequency is close to 1, body waves dominate up to a normalized distance of 100, due to their peculiar attenuation characteristics which are very similar to those of Rayleigh waves.

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Aftershock records of the Hyogo-ken Nanbu earthquake of 1995 observed in the Higashinada Ward in Kobe are analyzed to find the appropriate ground models at each sites. Then main shock ground motions there are estimated based on these models. Spectra at the sites on sand layers 10m to 20m thick show considerable amplification compared to those on hard rock. Spectral ratios of horizontal components between them can be modeled very well by the 1-D ground models derived from the boring data (N-values) and geophyisical exploration. We try to reproduce ground motions at these sites by using equivalent linear or effective stress analyses with these soil models and the main shock records observed on the hard rock. We found that equivalent linear analysis gives us estimated peak accelerations of 670-1,130 Gals and peak velocities of 140-170 cm/sec and that effective stress analysis yields peak accelerations of 630-1,000 Gals and peak velocities of about 130 cm/sec. Thus we can say that ground motions in the heavily damaged area in the Higashinada Ward must reach to the level of 600 Gals in acceleration and 130 cm/sec in velocity at least.

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A geometrically unstable structure constituted by bar-members, such as a tensegrity or a cable net, which is stabilized by prestressing, is usually very deformable, especially when it is subject to asymmetrical loading. In view of the above, the authors have developed a nonlinear programming method with nonlinear domain equations to find its minimum deformation shape. The present paper gives a method, which adopts general reduced gradient method (GRG) with linear domain equations, to find the optimum shape with maximum rigidity of a tension structure. By this method, the analysis procedures can be simplified and the computer calculation can be speeded up. The present paper demonstrates that the shape of maximum rigidity of a tension structure is dependent on the loading patterns, but not on the module of the load vector. A tensegrity frame is taken as an example for the numerical analysis.

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Confining effect of concrete pillar by circular hoops is analyzed assuming as follow. 1) Mohr's theory of failure is applicable to concrete under triaxial compression. 2) Stress field is given by functions so that principal stresses distribute like an onion with a core. The equilibrium conditions are considered approximately, but not rigorously. Thus, imaginary body forces are assumed to satisfy the conditions. The functions of principal stresses are determined so that the imaginary body forces are minimized. According to the lower bound theorem, the maximum strength may be chosen as the strength of a pillar. The pillar strength decreases as the hoop spacing increase, even if shear reinforcement ratio is the same. This tendency agrees with existing experimental results quantitatively.

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The objective of this research is to investigate the post-yield performance of a plastic hinge in a reinforced concrete using longitudinal reinforcing bars with high yield strength ratio. Three 1/2 scale reinforced concrete cantilever beam specimens were subjected to statically cyclic load with increasing amplitude to failure. Variables in the test were (1) yield strength ratio of longitudinal reinforcing bars and (2) with or without reinforcing bar couplers at the critical section. Test results showed that (1) longitudinal reinforcing bars with 90% yield strength ratio ruptured at critical section at the deflection angle of 1/20, due to the concentration of strain within its small hinge region and that (2) concentration of strain at critical section was not accelerated due to the couplers.

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New construction methods have been developed to save labor and wood resources at construction sites and shorten construction periods of reinforced concrete buildings. The joint method is a type of lap splice, in which main bars are butted together at the midheight of the column and reinforced with small-diameter splint bars. These splint bars are contained in a precast concrete shell form (PCa-shell) for columns. The results of structural experiments on reinforced concrete members which have been designed by this method are explained in this paper. It appeared that the tie bars, which were installed in the PCa-shell, improved structural performance and that shear and flexural strengths were the same as with non-spliced PCa-shell members. Bond design methods for this joint type are further proposed.

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The practical - scale "unbonded braces" were tested and the following conclusions were obtained. 1) Basic model : In the practical - scale test, it was confirmed that the stable hysteresis characteristics was obtained up to an axial displacement of ± 50 mm (axial strain : approximate 1/80). 2) Thin-walled pipe model : Safety from buckling under the present design standard is sufficiently high. 3) Model with different unbonding material thickness : In the elastic region, there is no difference in initial stiffness. It was, however, found that if the thickness of the unbonding material is increased, plasticization proceeds at a higher rate due to delicate undulation of the core steel plate. 4) Model using different grades of steel as the core : There is possibility of producing a brace which can freely control the hysteresis characteristics. 5) Eccentric model : In the "elastic region" corresponding to the behavior of the brace which is set in the frame, a sufficiently high buckling constraining effect can be obtaind, regardless of the magnitude of eccentric moment. Lateral deformation and rotation proceed in the plastic region and maximum strength decreases in the compressive region.

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An elasto-plastic analytical method including the effect of strain hardning is developed to evaluate the load-deformation relationships for bolted T-stub connections. Tension-elongation relationships of high strength bolts are idealized by a smooth function, moment-deformation relationships of flange are simulated by an elasto-plastic function, and a set of equations based on the equalibrium and compatibility considerations is obtaind for four deformation modes . A series of loading tests is conducted to verify the feasibility of the analysys. The analytical results correlate very well over the entire load history. The tests and the analysis also show that the maximum strength of a T-stub is affected by the stiffness of the plate to which the T-stub is connected.

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This paper describes the load-displacement relationships and the strain distribution of beams. These beams are fabricated from high strength steel with low yield ratio, or high yield ratio. But the nominal tensile strength of these steels are 590N/mm^2, together. The large deformation behavior of these high strength steel beams are obtained by experiments and numerical analysis. The plastic deformation capacity of these beams are evaluated by the difference of their material properties and width-thickness ratio of these plate elements. And the plastic deformation capacity of high strength steel beams are compared with one of the ordinary steel.

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The dependence of the thermal responses of composite floors on the cross sectional shapes is calculated by a model of heat and mass transfer. The model takes into account of the heat and mass transfer, the desorption of physically adsorbed water, and the thermal decomposition of water of crystallization. While the average thickness is kept constant (115mm), the rib sizes are changed. The fire resistance time is determined for each shape based on the ISO 834 criteria for temperature rise of unexposed surface. In case of small ribs, the fire resistance time is determined by the average temperature rise of the unexposed surface. On the contrary, as the rib becomes large, the fire resistance time is determined by the maximum temperature rise. Between these rib sizes, the two criteria are exceeded at the same time. We call these shapes as 'thermally optimum' in the sense that there is no redundancy of concrete. It is shown that the thermally optimum shapes are the imit of rib size in order to assure the insulation function of composite floor. It is also shown that the rib volume (rib height times rib width) is approximately constant in thermally optimum shapes.

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