This report studied effects of applying ultrasonic waves on concrete in mixing works, by measuring compressive strength, slump, and air content, and by investigating the microstructure of the hardened concrete. The results showed the increase in compressive strength, but little influence on slump and air content. It was also observed that the microstructure became more dense, especially in the interfacial zone between aggregate and cement paste.

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This report shows experimental results for the influence of porosity of high-strength lightweight concrete upon properties of hardened concrete, such as compressive strength, fire resistance, freezing and thawing. These results are as follows ; (a) In regard to inner porosity of lightweight aggregate, it was observed the tendency that expanded shale type has a lager radius than that of sintered fly ash type. In case of the large sized aggregate, this tendency is more evidently, and the influence of radius size of porosity and aggregate is confirmed at high strength area, (b) The extent of influence of curing methods for porosity of this type concrete differ from shape and size of specimens, (c) Compressive strength of concrete is evaluated by effective pore volume under any curing condition, but these relationships depend on types of aggregate, (d) Resistance of freezing and thawing or fire of light weight aggregate concrete is not necessary to advance under moisture condition, because of light weight aggregates, due to their cellular structure, capable of containing more water than normal weight aggregate, (e) Fire resistance of high-strength concrete is lower than that of normal-strength concrete. The safety range of fire resistance is confirmed by water content and medium pore radius of concrete.

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This paper presents a method to evaluate the slipperiness of floors and pavements from a viewpoint of safety on riding a bicycle, which is based on the relation between the evaluating scales of slipperiness and slipperiness index (C.S.R-BIKE), measured with developed slip meter reported in part2. The outline of this study is as follows. The first, the evaluating scales of safety of slipperiness were made by sensory test by means of floors and bicycle. Then, the C.S.R-BIKE of floors was measured with the developed slip meter. Based on the relation between the evaluating scales and the C.S.R-BIKE, evaluation index and evaluation method of slipperiness of floors and pavements from a viewpoint of safety on riding bicycle was presented.

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The purpose of this study is to find physiological parameters about fatigue during standing, then to consider a correlation between fatigue and hardness of floors. Three fatigue tests were taken place during female subjects kept standing 90〜180 minutes. At fatigue test I, tow parameters which had a possibility to correspond to fatigue were selected among eight parameters. Furthermore one parameter as called number of step changing which had a possibility to indicate the different response among different floors was decided among tow parameters detected throughout from fatigue test II. Then, with results of fatigue test III, the correlation between fatigue and hardness of floors was presented by means of decided physiological parameter.

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In Part2, we designed two types of stain accelerating devices. In this Part, we adopted the device which we thought would reproduce stains closer to the real stains and made a sensory test on materials exposed to the air in a smoking room and materials stained by the device. After careful consideration of the results of the sensory test, we created the evaluating scale for cigarette smoke stain, and concluded that the physical quantity (color differential + 〓b^*) indicated the state of stain (〓b* : the change quantity of the CHROMATIC index of stained and un-stained materials). In what follows, we will show a way of evaluating cigarette smoke stain on the basis of the relationship between the stain evaluating scale and the physical quantity of materials and present the evaluation index and the evaluation method for stain.

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The purpose of this study is to present the lower criterion of C.S.R not to slip at the landing when people step on the slippery surface without the knowledge of the slipperiness changing. In this paper, first, it was made clear that the most dangerous motion was fast walking at the speed of one-point-two-two times the height per second. So, fast walking and walking at natural speed were selected as motions to be investigated. Secondly, from the investigation of the load applied to the floor while these motions, the load to be simulated by "Landing Slip Meter" was established.

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This study evaluates live load intensity that is independent of structure type. Live load intensity was calculated for six uses : dwelling, hotel room, classroom, office, theater with fixed seats and library stack room. A model was investigated for each. The room areas were divided into similar units, and the live load was calculated for each unit. These models are classified into types on the basis of their use. For example, in dwellings, most furniture is concentrated along walls while in classrooms and theaters it is distributed uniformly over the whole area. Thus, the live load intensity model varies depending on the type of use. In conclusion, it is possible to estimate live load intensity with these models, and the result can be applied in the analysis of large span structures and in checking for cracks.

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This paper proposes the method to estimate a structure coefficient Ds based on displacement response. First, estimation formulas of displacement response are evaluated for the bi-linear type design velocity response spectrum using the equivalent linear method. Next, the method to determine a value of Ds is proposed by using the estimated displacement response. Finally, trends of the values of Ds determined here to the initial period, energy absorption ability, and allowable deformation are investigated. They have the following tendencies. 1) Increase like a hyperbola having the upper limit along with the reduction of the period ratio TR. 2) Reduce like straight line along with the increase of equivalent viscous damping coefficient β. 3) Reduce like straight line or like the exponential function having the upper bound along with the increase of allowable ductility factor μ.

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This paper presents a numerical method for the analysis of the free vibration behavior of arbitrary shape strip plates by using the Rayleigh-Ritz approach, together with some numerical results. The method is based on the arbitrary curved coordinate system using a infinitesimal deformation theory. Numerical results are compared with the available ones in the literature and in the F.E.M. The comparison shows the method presented in this paper is useful for analyzing the free vibration of arbitrary shape strip thin plates.

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This paper presents the methodology for H^∞ structural controller re-design based on an identified structural model with AMD providing a random input. The transfer function of the controlled structure is identified by mean of linear regression model-based relationship between input and output. The identified transfer function provides us with the natural frequencies, damping ratios and reduced-order modal matrix with the same dimension as the number of output-measured stories. Based on the obtained model of the structure, H^∞ controller can be re-designed. The effectiveness of this methodology is demonstrated by conducting computer simulations for a 20-story building. This methodology could be also applied to other theory-based controller than H^∞.

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The lack of proper guidance on the seismic behavior of frames when filled with brittle elements like masonry infill walls in most design codes has motivated this study. Considering available experimental data, an idealized hysteretic model for the brittle element is proposed and incorporated into dynamic analysis program where inelastic response and reliability assessment are conducted under simulated ground motions. Approximate solutions for the average and standard deviation of accumulated plastic energy and ductility factor imposed on the frame are found in closed form expressions. In general, plastic energy and ductility demands-based infilled frame reliability is found to be higher relative to bare frame depending on the level and duration of input motion intensity and mechanical characteristics of the system.

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This paper aims at presenting the effectiveness of providing a low to mid-rise building with a soft first story subject to active or semi active control against seismic excitations. The control is based on the sliding mode control theory, in which sliding surface is so designed as to shift in accordance with the seismic acceleration, improving greatly the effects on displacement reduction. It is confirmed by earthquake response analysis of a five-DOF shear model that both an actuator and a capacity adjustable viscous damper is available for the purpose.

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Viscoelastic dampers (VE dampers) have been used in the earthquake-resistant and wind-resistant design of tall buildings for about 30 years, because they have strong damping effect against from small to large vibration. After Northridge earthquake in US A 1994 and Hyogoken-Nanbu earthquake in Japan 1995, viscoelastic dampers, as a part of passive energy dissipation system, are getting more attention in the seismic design of building structures. However, the mechanical characteristics of viscoelastic material are very sensitive to the temperature of VE material and frequency of structural system, the mathematical formulation of hysteretic model is too complex and difficult to be used directly in the actual dynamic response analysis. This paper presents the determination method of elastic stiffness k and damping coefficient c for the simple Kelvin-Voigt model based on the results of dynamic loading test of VE dampers. In order to use the Kelvin-Voigt model and the empirical formula of elastic stiffness k and damping coefficient c directly into the time history response analysis, a new concept of transient frequency is proposed in this paper. It is confirmed that, the proposed simple model has good agreement with the results of random dynamic loading tests.

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As arise great demands for maintenance of functions and protection of properties, recently many base isolated buildings have been constructed. Depending on the geometrical shape and occupancy type of buildings, mid-story isolation system is more suitable than conventional base isolation system for some buildings. Therefore, it is necessary to shed light on the seismic behavior for buildings with the mid-story isolation system. For the mid-story isolated buildings, nonlinear time history analyses as well as modal analyses with equivalent linear model were carried out. As the results, it is concluded that the mid-story isolation system is effective in reducing the seismic response and if the effect of higher modes related to the location of isolation devices can be properly evaluated, the proposed system is considered to be one of the efficient choices in the seismic design.

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Analytical studies concerning lateral seismic earth pressure on a building model are summarized as follows. 1. Lateral earth pressure on a deeply embedded building model during an earthquake is composed of relatively long-period lateral earth pressure with the same phases on opposite sides and short-period lateral earth pressure with reversed phases on opposite sides, of which period is shorter than the fundamental natural frequncy of the building. 2. The observed characteristics of lateral earth pressures, concerning amplitude and phase, can be well reproduced by multi-input analysis based on the observed waves under the ground. 3. Amplitude and phase of lateral earth pressure are remarkably influenced by the incident angles of input motions. The observed amplitude and phase of lateral earth pressure are well reproduced by analyses with the assumption of 5 to 10 degrees as the incident angle of input motion. These angles are coincident with the general incident angles of actual earthquakes.

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A seismic hazard map, indicating the regional distribution of expectancies of ground motion intensity, has to be constantly updated in tandem with advances of seismology and earthquake engineering. In this paper, the authors propose to make out a new seismic hazard map of Japan, drawing on the recent results of studies relating to the maximum magnitude model of active faults, the modified attenuation formula of ground motion amplification based on the Digital Nation Land Information. The authors in conclusion show the distribution of expectancies of ground motion velocity in a 500-year period for the entire Japanese archipelago.

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New stress functions introduced by prof. Tosaka and prof. Sueoka for expressing stress components at a point in three dimensional elastic body are used in a theory of plate bending including the effect of transverse shear deformation. Two conditions of compatibility are obtained as governing differential equations expressed by new stress functions. Displacement components and resultant stress components acting at a point of section of the plate obtained by employing double trigonometric series agree with these obtained by using displacement method in expression. It is shown that numerical results of displacements, bending moments and shearing forces for a uniformly loaded rectangular plate with two opposite edges simply supported, the third edge clamped, and the forth edge free, agree with calculated results by employing displacement method.

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The fuzzy design problem of building structures which satisfy the specified grade is formulated. (1) By using the solution to the corresponding optimum crisp design problem, the determination method of fuzzy constraint for object function is presented. (2) In this problem, the design variables are fuzzy numbers and α-level set of fuzzy theory is used. (3) The solution to this fuzzy problem is derived directly from the solution to the corresponding optimum design problem of crisp numbers. By selecting the members out of the the range of fuzzy solutions, building structures which satify the specified grade can be easily designed.

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In the present study, we conducted out the flexural test of column corresponding to the first story in tigh rise frame consisted of precast concrete syructure, in order to investigate the mechanical behaviors under seismic load. This paper aims at evaluating the ultimate flexural capacity of a precast concrete column connected by grout-filled coupling sleeves for the steel bar with high strength. By using the theory of compressive struts constituted in precast concrete column, the model on tie action and arch action is conducted and its conformity to experimental results is verified.

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Equations to estimate buckling strains of compressive longitudinal reinforcement arranged in confined concrete are derived, through discussions on results of our experimental studies. In the tests of confined concrete with longitudinal reinforcement under uniaxial compressive loading, effects of following factors on the buckling strains were investigated, such as ratios of lateral reinforcement pitches to specimen diameters (S/D), an index of confining stress (ps σ sy), yield strength of the lateral reinforcement (σ sy), shapes of lateral reinforcement, compressive strength of plain concrete (Fo), diameters of longitudinal reinforcement (φ) and locations of longitudinal reinforcement Comparisons between test results of budding strains and estimated ones show that the derived equation has successful applicability about ± 30%.

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We've checked the present AIJ design formula to estimate shear strength of SRC members referring the database of experimental results, and clarified the problem. There are two types of design formulae to estimate shear strength based on the theory of plasticity. The one satisfies the equilibrium condition among flexural force, shear force, and axial force, and the other doesn't satisfy. The former type agrees with the theory, and fits in the purpose of calculating the strength of designed members. The latter type fits in the purpose of calculating the amount of steel bar necessary to resist the given external force. First we've proved that we could estimate the ultimate strength of SRC members as same as RC members by the former. In the second place, we've proved that we could construct the design formula to estimate shear strength by the latter.

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This paper reports an evaluation method for the shear strength of interior joints consisting of steel beams and reinforced concrete columns. The shear strength is generally calculated by the sum of the nominal shear resistance of a steel web panel and concrete elements. In this paper, the shear strength is calculated in consideration of the relation between the shear crack and the maximum strength of beam-column. Design equations presented herein are evaluated through comparison with existing experimental results. The comparisons between experimental and calculated results indicate an excellent agreement.

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Recently, the development of coastal zone has been advancing, and the chance of human activity has increased near the sea. On the other hand, destruction of ozone layer has resulted in an increase in the amount of ultraviolet radiation reaching the earth surface. The human body is harmfully influenced as skin cancer and eye damage by ultraviolet radiation. Especially, the effect of ultraviolet radiation on beach is higher than that inland area due to the reflection from the sand surface. This report shows measurement method of ultraviolet reflectance on wide sand surface using ultraviolet radiation camera and reflection standard board. From the measurement results, the ultraviolet reflectance on sand is from 3 % to 8 %.

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The authors claim that to represent the knowledge for planning is necessary to implement a computer aided planning system for structural design. The authors regard the planning process as the process of selecting action that modifies the sate of affairs to the desirable state for the designer, and intend to propose a representation schema of the planning knowledge use in structural design. The proposed schema is composed of deduction based on theoretical knowledge, heuristics, abduction based on theoretical knowledge and practical reasoning employing knowledge about action. With the proposed schema, examples of the structural design planning for the seismic retrofit is represented formally. The authors may conclude that the schema is valid for representing planning knowledge on structural design.

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In this paper, three items of discussed in the present paper are as follows ; 1. Why did the authors assume 2/Lx, 2/Ly on Matrix [A] ? 2. Why did the authors assume that the shape of yield surface is a octagon ? 3. On the computing in the present paper, the authors use Prager's hardening rule and Ziegler's hardening rule. Each computiong data have different physical characteristics. Why did the authors compare with both computing data?

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The authors answer Mr. H. Uehara's questions as follows. The number of the answer corresponds to that of the question. 1. The authors used 2/Lx and 2/Ly as components of transformation matrix [A], because those components made a series of formulations simple. 2. The authors did not assume the shape of the yield,surface. The shape of the yield surface necessarily depended on the structural model, and was an octahedron. 3. It is a matter of course that different assumptions cause different physical characteristics. The authors compared the two rules to make clear the difference.

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