The purpose of this study is to present a relative evaluation method, on hardness of floors from the viewpoint of stability of footing. First sensory tests on hardness from the viewpoint of stability were taken place to make psycho- logical scales with thirteen healhty men and seventeen sample floors. Secondly an apparatus to measure physical values of floors which corresponded to the psychological scales was developed. Finally evaluation indexes which were composed of the psychological scales and the physical values, and a measuring method of the physical values were presented as a relative evaluation method.

View full abstract

This study presented the method to evaluate the slipperiness of inclined floors from a viewpoint of safety. We grouped inclined floors into two classes from the condition to set foot on them. Then, in order to. make the evaluation scales of slipperiness, we carried out the sensory tests on inclined floors. Next, we proved that the slip resistances which were composed of C. S. R and gradient corresponded to the evaluation scales. As a result, the method to evaluate the slipperiness of inclined floors was presented as the method to measure the slip resistances and the evaluation indices.

View full abstract

A lot of study concerning the first-excursion probability of a random process has been carried out. So far, series approximation derived from the theory of random process, an.approximation based on the maximun entropy principle and based on the, Markov property have been developed. In this paper, it is shown that it is possible to get approximately a simple analytical expression to evaluate the first-excursion probability with the threshold'levels defined by random variables, by introducing the, concept of the survived probability process.

View full abstract

An analytical approch for predicting the mean and fluctuating internal pressure induced by wind between double walls when the outer wall is provided with openings has been investigated. The method of analysis was based on jet simulated air-flow through the openings and a model of pressure flow between parallel planes. The analytical results were compared with wind tunnel results, and they matched closely if the proper values for flow resistance between the double walls were used. From these results, the analytical method described in this paper was found to be effective in predicting the mean and fluctuating internal pressure between the double walls.

View full abstract

This paper describes a foundation work for reducing the earthquake response, of structures founded on firm rock. A high damping material is laid in the clearance between the basemat and the underlying rock, thus giving a higher damping factor to the structure and reducing its earthquake response. The effectiveness of this foundation work was examined analytically with changing the damping factor and the thickness of the material used in this foundation work. In order to develop the high damping material, the material tests were performed for the mixture material of gravel and asphalt.

View full abstract

The present paper investigates the elasto-plastic buckling loads of single layer latticed domes on a rectangular plan. The domes are composed of beam elements of which ends are connected by elastic springs. The domes are analyzed in three ways : linear eigenvalue, geometrically non-linear, and geometrically and materially non-linear analysis, considering several circumstances as subtended half angle of members, slenderness of members, boundary conditions, geometric imperfections, member crookedness and loadings. Based on the results, discussions were made how the pin-connected dome buckling, shell-like buckling or member buckling occurs, .while presenting the method for non-dimensionalizing the buckling loads.

View full abstract

The influence of model conditions was discussed, and it was confirmed that the scale factors for forces due to stresses, nail joints, external loads and the gravity are required to be simultaneously equivalent. The pilot tests using full-size, one-half and one-third models were performed to demonstrate the similarity. The results suggested that the satisfactory racking similitude in quantity depended on the diameter of nail in addition to materials and the scale of members.

View full abstract

In this paper, experimental results on specimens with bolted joints are compared with the analysis of the generalized theory of a beam on an elastic foundation. The above specimens have the different five conditions : (1) execution method, (2) thickness of infilled epoxy, (3), (4) strength and thickness of side members, (5) number of bolts. As the results of the examination, a numerical analysis based on the above theory is applied to approximate the nonlinear load-slip relationship of bolted wood-joints with a steel central member filled with epoxy.

View full abstract

In order to make the maximum bending moment of a beam reach the ultimate flexural moment of a timber beam reinforced with steel plates attached by metal connectors, it is necessary to find out the potimum relationship between reinforcing steel plates and metal connectors. This paper deals with the elasto-plastic behavior and the ultimate load of a reinforced timber beam subjected to centrally concentrated and equally distributed load and simply supported at both ends. For timber beams which are relatively long, minimum conditions required for metal connectors to make reinforcing steel plates yield are obtained with the analytical method presented in the previous paper.

View full abstract

The experimental study on response of reinforced concrete slab-beam-column connections to unidirectional and bidirectional seismic loads was conducted at the University of Texas at Austin in the United States as part of the US-New Zealand-Japan cooperative research program on earth-quake-resistant design of beam-column joints. This paper outlines the US tests and compares the test results with those in New Zealand and Japan, focusing on the ultimate load carried by the beam-column joints. The shear strength of the joints under unidirectional and bidirectional loads is discussed herein based on the test data in the US-NZ-Japan research program and those reported elsewhere.

View full abstract

The cyclic load tests of the beam-column sub-assemblages were performed on the multi-stoned frame of a R/C-structure with wall columns in order to investigate the characteristics of shear behavior of the beam-column joints with various anchorage types of main reinforcing bars Conse-qeuntly, the rigid frame with wall columns can obtain the enough capacity of deformations without any loss of shear strength which is independent of anchorage types of beam reinforcing bars It has been also recognized that shear strengths are varied in anchorage types, and that to some extent, they are corresponding to horizontally perspective length of anchorage bars

View full abstract

The 2-D non-linear finite element analysis has been performed on .three different types of bar arrangement in R/C wall column and beam joints for multi-stoned frame structures in order to investigate the shear resistant mechamsims of the joint Consequently, it has been found that modelling the mechanisms of bent bar anchorage with bond linkage elements can lead to the way to describe the behaviour of beam-bar anchorage inside the joint It has been also understood that the shear resistant mechanisms of the joint are mainly attributable to the compressive strut-action, and the sub-strut-action by the bent bar anchorage.

View full abstract

We have been developing the elasto-plastic earthquake response analytical method for highnse reinforced concrete (R/C) space frame, which can consider the effect of varying axial force and biaxial bending moment on columns This analytical method was applied to the earthquake response analysis of a 30 story R/C building In order to understand the effect of bi-directional earthquake excitations, uni-directional and bi-directional response analyses were performed using the strong ground motions at three sites This paper presents the difference of the inelastic behaviors of the R/C space frame in each analysis case, and examines the design stresses for columns during the bi-directional earthquake excitations

View full abstract

In order to obtain the basis for the limitation of the constant external forces to ascertain the aseismic safety of structures and their members, the accumulation of deformation and strength deterioration were investigated analytically for three-element models The theoretical solutions of the axial force at the boundary that the accumulation of the strain converges and tthat the beamcolumn collapses were derived under a certain value of the centroidal axial strain, and were compared with the results of elastic-plastic analyses

View full abstract

In the seismic design of general buildings, plastic deformations in some parts of the structures are permitted to absorb the energy of large earthquakes As there are many members with a slender ratio over 100 in the steel truss structures, the buckling of these members easily occurs After the occurrence of buckling, the mechanical properties of the steel members would not be ductile For this reason, it is quite difficult to perform the seismic design by permitting the plastic deformation of the steel truss structures In this paper, by using special pipes with another pipe inside for compressive members of truss structures, it is possible to protect buckling and enlarge the abilities for the resistance against loading forces and deformation capability iThree experiments for about one twentieth scale model of the steel six grids planner truss structures, namely, (a) normal truss structure, (b)truss structure with the non-buckling member in the center of upper chords and (c) truss structure using the non-buckling members for all upper chords, were performed to investigate the mechanical properties of the structures The loading was performed by rotating the warm-gear by using stepping motor through the round steel bar attached to, the nodal point on the lower chord members Five loading systems were controlled simultaneously by personal computer It was found out that the improvements for the force-deflection relationship were showed with protecting the buckling of the members Numerical analysis for these specimens were also performed and the results could explain the mechanical behaviour of experiments

View full abstract

The compressive strengths of concrete-filled tubular members are reduced by plastic axial stretching One of the reason of strength reduction is tensile cracks of infill concrete The infill concrete, which has cracks due to the tension, has no resistance of axial compression until the cracks close again The paper shows the characteristics of axial behaviors of the members by test and numerical analysis, and the condition on which the concrete-filled tubular members prestretched plastically keep the compressive strength same as monotonic ones

View full abstract

We have been proposing the "Adaptive Metamorphosing Building (AMB)" as a long life building The AMB changes its structural shape and functions in order to adapt itself to changes in demand on the building We deal with the shape optimization problem of the AMB and present how to decide process and quantities of the extension, repair, and so on The total extension process of the AMB is modeled using two dimensional finite elements and its depth distribution, which can be regarded as its space distribution, is determined so that its integlated total strain energy is minimized

View full abstract

An analytical approach which predicts the dynamic behavior of a circular flexible floating is land subjected to vertical ground motion at seabed is presented, taking into accout the dynamic interaction among the island, sea water and anchor system The floating island is modeled as an elastic circular plate with tension-legs Based on a linear potential flow theory, the hydrodynamic pressure generated on the wetted surface of the island is obtained in closed form The modal equations of motion of the island with or without anchor system are derived by energy method The response quantities are evaluated as root-mean-squared values using a stationary random vibration theory Numerical examples are presented to discuss the effects of anchor arrangement and ground motion characteristics on the island response.

View full abstract