Slip resistance of stairway treads would be one of the most important physical factors which influence stairway safety. But it's quantitative evaluating method has not been established. The purpose of this paper is to investigate an effect of slip resistance of stairway treads objectively, and also to prove the possibility of establishing it's evaluating method. The outline of contents of this study is as follows. (1) Two kinds of model stairways are designed and produced for sensory test. One has highly safe riser/tread dimension, and another has extremely dangerous dimension. Treads of each stairways have various degrees of slip resistance. (2) Evaluating scales of slip resistance of stairway treads, namely, 'safety scales' are composed by means of sensory test. (3) Coefficients of slip resistance (C. S. R) of stairway treads, which would indicate proper degree of slip resistance of treads, are measured by using our originally developed slip tester (0-Y・PSM). (4) Correlations between safety scales and C. S. R are examined. After all, as the results of experiments stated above, following conclusions are obtained. (1) The influence of slip resistance of stairway treads on stairway safety is made clear objectively. (2) The method of composing safety scales is sufficiently available. (3) Applicability of 0-Y・PSM and C. S. R. is basically confirmed. (4) Establishment of quantitative evaluating method of slip resistance of stairway treads is proved to be possible.

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Although the consistency of concrete can be increased by adding vibration, the effect of vibration is continually lowering in the setting process of concrete, and the rate increase rapidly according as the hydration of cement actively. The hydration process of cement is divided into dormant period and acceleratory period according to its characteristics. In this paper we have discussed that the expiration of dormant period can be clearly specified by the characteristics of the change with time of the dynamic shear modulus of cement paste and mortar, and that the properties of revibrated concrete show the remarkable change according to the time when the vibration is added;that is dormant period or acceleratory period. Thus the boundary time was defined as the initial set. It is cleared that the initial set is affected by a water-cement ratio of mixtures;i. e. the lower the water-cement ratio, the later the time of initial set, and that the initial set is independent of the content of aggregate. Furthermore we have discussed on the standard method of test for the time of setting of concrete mixtures by penetration resistance, then following were cleared. The penetration resistance is insensible to hydration of cement (as is estimated from the fact that the penetration resistance is independent of water-cement ratio of mixtures). Therefore the progress schedule of concrete works may not be controlled well by a fixed value of penetration resistance. To provide a practical usage for penetration resistance test method, the penetration resistance for initial set must be classified according to the mix of concrete.

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Staining on external walls is one of the important problems from the point of view of marring the appearance of building. This paper aimes to obtain the basic knowledge of stains those occur from the flowing rain and to clear the influence of flowing suspension on tristimulus values of porous cement material surfaces. The conclusions are as follows ; The tristimulus values decrease with the increace of total quantity of the flowing suspension and approach to stationaly values. Changes of the tristimulus values are explained by a material coefficient and total quantity, dencitv. flux of the flowing suspension and the experimental results were in fairly good agreement with calculations.

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Energy absorption capacity is an indispensable property for earthquake resistant structures. To equip the top story with abundant energy absorption capacity and to make damage due to earthquakes concentrate on the top story result in an promissing design option which has not been hitherto investigated. In this paper the mechanism through which the input energy moves to the top story is clarified and the design criteria for this tvoe of structure are exoressed in terms of D-values.

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We designed three towers which change configuration using electricity and oil pressure, exhibited in the International Exposition Tsukuba, Japan, 1985. 'Revolvo-balance Tower' is composed of 3 bars coupled by pins successively. Because of the eccentricity of mass, this tower moves very irregularly. 'Dancing Tower' is composed of 2 rigid trusses coupled and supported by 2 groups of 6 bars. Because of the geometrical characteristic, 2 trusses translate in holizontal circle. 'Extenso Tower' is composed of 2 groups of 8 triangular prisms coupled by pins. Because of the geometrical characteristic, the 2 groups moves simultaneously changing configuration, from folded to extended and from extended to folded.

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Since 1978, we have been conducting practical studies of the Base Isolation System. This paper concerns studies of viblation behavior and the base isolation structure using the shaking table test simulating the actual scale of observed strong earthquake waveform. The studies enabled us to analyse the dynamic behavior of structures in earthquakes (and acculately assess practical design implications) by application of viblation theory, and use of an elastic filter called an ISOLATOR, to structures for base isolation with earthquake energy absorption apparatus. We concluded that the reduced system in earthquake is particularly effective in Buildings with a low or midium number of storevs and that greater freedom of design is made possible.

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Mild steel portal frame specimens are tested under the constant vertical and monotonic or alternating horizontal loads in order to clarify the influence of the lateral-torsional buckling of the columns on inelastic behavior of steel frames. The frame specimens are assembled by welding from H-shaped columns and a rolled H-shaped beam. As the parameters, slenderness ratio about weak axis of a column and axial load ratio of the columns are selected. Twelve specimens are tested. Horizontal load earring capacity and deformation capacity are investieated.

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The coefficient lists on the term of loading (fixed end moment and horizontal thrust at fixed end) are expressed in the five significant figures with the values of uniform section girders as unit and these are made on the following three conditions. Condition 1 Lengths of rigid zones at both ends are ξ_il'=γ_il=ξ_κl=γ_κl=(0.00〜0.30)l calculated with an interval of 0.02 I. Condition 2 Numbers are given to each six types of working load. Condition 3 No. 5, 6 are made at the load working point α=0.2, 0.3, 0.5. The list on the shearing force at fixed end is omitted since the shearing force can easily be calculated from the fixed end moment shown above and etc. These calculations were made bv comouter HITAC M-180 and microcomouter FM-11.

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Spandrel-walls frequently adopted for reinforced concrete buildings such a school and hospital sometimes cause shear failure of columns, which accidentally bring brittle failure of whole structure. Typical earthquake damages of building in which the existence of spandrelwalls was considered as one of majar reason of their damages were seen in the 1968 Tokachi-oki Earthquake and the 1983 Nihonkai-Chubu Earthquake. Recently structural design method where columns are intentionally separated from spandrel walls by slit have been adopted so that such brittle failure of columns with spandrel wall might not occur and that total structure might resist earthquakes by ductility capacity. This paper describes experimental results of column and spandrel wall assemblies with or without slits subjected to reversing static lateral loads, focusing on the effect of slit on the crack and failure patterns, yielding sequences of reinforcing bars and deformation capability. The test results of the strength of slit were compared to the analytical results based on strain distribution along the height of slit and stress vs. strain relations of concrete. Through the tests results and comparisons between test and analytical results, the following conclusions were drawn ; i) specimen without slit and specimens with thick slit faild in shear while specimens without spandrel wall and specimens with thin slit faild in flexure, ii) the strength of slit was expressed by the thickness of the concrete of a slit, the height of a slit and the compressive strength of concrete, and iii) the dimension of the concrete of a slit should be designed by based on the comparison between the strength of a slit and those of columns and beams.

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The present paper proposes the formulae for predicting the yield strength and the maximum strength of the moment joints. For the yield strength, by first, deriving analytically expressions to estimate the strength of the joints, and then empirically modifying them to reflect the previous test results. The proposed formulae very well explain the change of the failure modes from Model to Mode 2 (Fig. 15). For the maximum strength, the empirically formula to predict the local strength of RHS-column to H-beam connections in rigid steel frame is applied. The proposed formulae are summarized in Table 13.

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This paper analyzes the stress distributions of orthotropic wood plates subjected to concentrated forces. By two dimensional theory of elasticity for orthotropic media, stress distributions are obtained from the stress functions. In order to examine their validity the normal strains derived from the theoretical stresses are compared with the experimental results, which are measured by the strain gages. Then they are found in a fairly good agreement. Therefore these elastic solutions for orthotropic media are regarded as appropriate.

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