The purpose of this study is to minimize difficulties of information transmission with caused by electromagnetic wave reflection at building walls, in using the quasi microwave band for data communication. The electromagnetic material coefficient of each cement mortar is measured by using waveguide and electromagnetic wave absorption characteristic is simulated. As a result, cement mortar mixed with pitch-based carbon fiber or Ni-Zn ferrite had a better absorption characteristic than plain cement mortar. Combination cement mortar mixed with carbon fiber and cement mortar mixed with ferrite is improving in absorption characteristic, therefore proper combination is able to make electromagnetic wave absorber thin.

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The electronic devices using electromagnetic wave increases recently, and the mis-operation of the electronic devices occurs due to the multiple reflection of the electromagnetic wave. The measurement method of electromagnetic wave absorption in the VHP band (80-230MHz) has developed by the parallel wire line method. The method can be applied to the measurement of characteristic on electromagnetic wave absorption, ferrite mortar or carbon mortar, without microwave chamber. In this paper, the measurement method in the quasi microwave band (1700-2600MHz) is developed, the possibility and accuracy of the actual measurement is examined by this research.

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Permeability of placing joint of cement mortar during casting was measured for the specimens placed at various interval times at the combined environmental conditions of temperature and relative humidity. Temperature directly affects the permeability of them, and the rise of it increases permeability. However, a slight influence observed for humidity. Pore structure of placing joint zone was furthermore investigated by the Ga intrusion technique recently developed. The pore structure becomes coarse and finally a clear porous line appeared along placing joint, according to particularly rise of temperature as well as delay of the jointing time. Finally, the relation between permeability and proctor penetration resistance was discussed.

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Drying shrinkage and mass change of cementitious materials with standard substances for extrusion moulding are dealt with herein, especially focused on the cyclic effect of moisture and dry in constant temperature and humidity. The followings can be noted as the technological remarks for controlling moisture movements of the materials. 1) The features of drying shrinkage on cementitious materials produced by extrusion moulding are represented as residual strain and equilibrium one of drying shrinkage. The more the water content ratio is, the greater two types of strains are. 2) Drying shrinkage strain is able to be predicted on the basis of extruding pressure in factories. 3) Relationships between two types of shrinkage strains and logarithm of cyclic number are clarified to be presented as linear curves.

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A styrene solution of waste expanded polystyrene with a crosslinking agent and an initiator is used as a binder for waste wood-waste expanded polystyrene composites. The waste wood-waste expanded polystyrene composites are prepared with various binder contents and filler-binder ratios by using a hot press molding method. The apparent density of the composites is increased with increasing binder content and filler-binder ratio, while their water absorption and expansion in thickness are decreased with increasing binder content and filler-binder ratio. The maximum flexural strength and wet flexural strength of the composites are obtained at a binder content of 35% and a filler-binder ratio of 0.8. Decreases in the flexural strengths of the composites due to water immersion at 20 and 100℃ are hardly recognized at binder contents of 30% or more.

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The influence of the uplift of building base on an earthquake response is studied, using a multi-degree-of-freedom system of which parameters are assumed to be equal to the characteristics of actual building. Based on a dynamic response analysis, the following conclusions are obtained. 1) Uplift occurrence can be judged simply by using the proposed chart with good accuracy. 2) The response base shear force coefficient decreases when the uplift occurs. In some cases, the coefficient decreases to about 20% of the uplift restraint case. 3) The reduction of the base shear force by the uplift tends to increase in the case that the uplift occurs easily. 4) The uplift displacement can be controlled with decreasing the story shear force by adding attenuation material to the uplift part.

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This paper studies the ground motion amplification coefficient Gs is introduced in the calculation method of response and limit strength, whose calculation procedure is very complex. First, the approximate formulas of Gs, which are given by the impedance ratio of the linear soil, has been proposed. The formulas can be applicable also to the actual soil although those have been developed for idealized two-layer soil conditions. Next, it pointed out that the Gs may be underestimated depending on determination of the depth of engineering bedrock for the actual soil. Finally, two kinds of methods for the determination of the depth has been proposed so that Gs might not be underestimated.

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The variable damper using Magneto-Rheological fluid (MR damper) changes its damping force by changing the magnetic field acting on the MR fluid according to an electric current. Semi-active control using such a variable damper stabilizes building responses in an earthquake better than the conventional passive control. Basic characteristics of the MR damper have been clarified. This time, authors proposed control algorithm of base-isolation structure, which applied the optimal regulator theory. This control algorithm reduces response displacement and response acceleration for the purpose of, and aims at enhancements, such as safety and amenity. This paper describes shaking table tests on a three-story large-scale test frame with base-isolation structure. The test results verify the controlling system and the control effect as a semi-active device of the MR damper.

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This paper discusses a vibration control algorithm for a single degree of freedom model under non-stationary random disturbances. Selecting an appropriate set of passive mechanical parameters under a given feedback gain minimizes the energy requirement for the controller. This optimum selection is probabilistically obtained under stationary random process. It is also proved that the same optimum parameter selection minimizes the force requirement for the controller. The stochastically expected optimum parameter set is numerically evaluated in the time domain under non-stationary random excitations. The deterministic analyses ascertained that the control energy converges to zero as the time goes to infinity under any non-stationary random disturbances.

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In order to perform time history earthquake response analyses in consideration of both the dynamic soil-structure interaction and the nonlinear behavior of the structure, it is important to transform the soil impedance in the frequency domain to an impulse response in the time domain. The author have studied the time domain evaluation of soil impedance, and proposed a transform method. In this paper, deeply embedded structures in the layered soil were investigated based on embedded SR model. The strong frequency dependent soil impedance was transformed to the impulse response, and earthquake response analyses were carried out in the time domain. The efficacy of the proposed method was confirmed through these studies.

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A neural network approach is proposed to predict the nonlinear hysteretic behavior and dynamic response of wooden tenon joints using measured static hysteresis loop data. A multi-layered back propagation neural network is employed to determine the restoring force at the next loading step as an output with the displacement responses and the corresponding restoring forces at the past few loading steps as inputs to the neural network. In the training stage of neural networks, measured hysteresis loop data are ajusted such that the hysteresis parameters of each joint become identical with each other. The prediction accuracy can be improved significantly by adjusting hysteresis loop data with different hysteresis parameters and by taking an average of restoring forces predicted by different neural networks.

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An extensive study of the dynamic behavior of piled foundations with very short piles has been made by a series of centrifuge model tests and three dimensional finite element analyses. It was found from the model tests that the addition of very short piles to a piled foundation reduces, bending moments and shear forces of the piles at their head. It was also found from the series of finite element analyses that the earthquake response of a building is not affected very much due to the difference of the type of foundation (piled/piled raft) or of the connection condition of the pile at its head (rigid/pin). However, it was pointed out that the contribution of very short piles to the pile bearing shear forces is about 30 to 40 per cent and is found effective from the view point of earthquake resistance.

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The purpose of this study is to examine the mechanical characteristics of the moment resisting joints in the performance of timber frame structures, and to certify the influence of each element upon the moment transfer, through the bending experiments of three types of joints. As the result of this examination, it is clearly confirmed that the element relating to the moment transfer is the connecting elements by the drift pins and the round bar in the part of the tension side, and not only the same drift pin element but also the compressive strain inclined to the grain in the part of compression side. By this modeling of the joint, the derivation of the calculation formula in the rotation rigidity and the yield moment are shown in this paper. Next, the rigidity and the yield moment of the compressive strain inclined to the grain and the drift pin element are evaluated. Comparing the experiment results of the three types of joints and the numerical results obtained by the calculation formula, the validity of this calculation formula is confirmed.

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The objectives of this study were to propose a simplified method to evaluate axial load carrying capacity of transverse side walls connecting with reinforced concrete columns subjected to high axial load. Four column specimens were examined. Variables of those specimens were existence of side walls, location of side walls (centric or eccentric) and loading method of lateral force (bi-directional loading or uni-directional loading). Moment curvature relations of tested specimens were calculated by basic flexural theory under the assumption that plane remained plane after bending. Confinement from transverse reinforcement as well as rigid base stub of specimens was taken into account in the concrete model and feasibility of this concrete model was discussed in the paper. Furthermore parametric study using flexural analysis was conducted. Main variables of the study were sectional area of side walls, location of side wall and level of axial load ratio of columns. Methods to evaluate axial load carrying capacity of columns with side walls were proposed through parametric study using flexural analysis.

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In this paper some load-resistant models of Lrshaped beam-column joints on the top story of a building frame are proposed based on experimental research results. It is presented in the models that, for the external corner joints, not only shear mechanisms but flexural mechanisms also affect the joint strength. The flexural strength of the joint is determined by the anchorage strength of beam longitudinal reinforcement when the frame is subjected to closing moment. Subjected to opening moment it is influenced by transverse reinforcement in the joint and the projected development length of the beam or column longitudinal reinforcement. The calculated load capacities of the joints were compared with the experimental results, and good agreement was obtained.

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Based on the plastic theory, the author led the equation giving an yield surface of a story of an RC building by using the direction of the deformation of the story as the .parameter for the equation, where the yield surfaces of the members were elliptic, the deformations of the members obey the flow rule associated with their own yield surfaces, and the story have two degrees of freedom in horizontal direction. The equation was analyzed functionally, and general characteristics of the yield surface of the story, such as the shape of them and the relation between them and the deformation of the story, were studied. Through the study, the flow rule associated with the yield surface of the story, and convexity of the yield surface of the story, were proved.

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This research presents the proposal of predicting equation for bond splitting strength in case of no lateral reinforcement. Making the area of the equivalent bond stress block (EBSB) same as one of local bond stress versus slippage of reinforcement relationship proposed by the authors, the prediction formula for bond splitting strength is simply built. Assuming that bond stress is a constant value, strain and slippage of reinforcement are obtained from solving a simple differential equation. A new prediction formula is expressed separately in case of longer bond length than effective bond length and shorter bond length. The predicted bond splitting strengths show a good agreement with experimental results observed in previous studies.

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An adaptive loading system is developed to examine a design point of multi-story steel test frames under uncertain load pattern. Lateral loads are given as a random combination of basic patterns, and the system drives a test frame to the most likely failure situation. Plastic mechanism formation is adopted herein as the limit state, and two-story steel moment resisting frames are tested by this system under several random load properties. The results are compared with other deterministic responses, pseudo-dynamically tested under the excitation corresponding to each random load property. Similar plastic mechanisms are observed again in the pseudo-dynamic tests.

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Theoretical studies are presented on the elastic buckling load of a multi-bay multi-story frame with slender columns. Lateral sways of slender columns in the well or void space are so restricted by other short columns that the load carrying capacity of the slender column is larger than that of the independent long column. The interaction effects between long and short columns in the frame are expressed in an explicit manner, and the closed form estimation of frame buckling is presented. Methods for estimating effective lengths of such frames are also presented, where the single buckling of the slender column dominates. Computed results show good agreements between presented formula and eigen-value solutions.

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The authors have already reported the results of the study on the shear/resistance of anchor bolt concerned with diameter of anchor bolt, side cover and edge distance to the concrete footing, when shearing forces act upon embedded anchor bolts. Considering the damage conditions of bolts in past earthquakes, in this paper the authors will analyze the failure characteristics of the anchorage of bolts and evaluate the ultimate strength when the bolt heads are subjected to tensile and shearing forces using the specimens whose distance from center of anchor shank to the edge of concrete footing is comparatively short.

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Author had presented the numerical model for exposed-type column base , which can treat the behavior of semi-rigid connection under variable axial force. In this paper, the applicability and availability of the numerical model is confirmed through the cyclic loading tests on the cantilever with the exposed-type column base. Also, the influence of variable axial force on the rotary stiffness and moment carrying capacity of the column base are investigated. Through these studies, it is clarified that 1) the rotary stiffness and the bending moment carrying capacity of the column base varies in accordance with the variation of axial force, 2) the concentration of plastic deformation in anchor bolts and the deterioration of bending moment carrying capacity in column base are observed when tensile axial force increment acts on the column base, 3) the numerical model could reproduce the deformation mechanism due to rotation of the base plate, the variation of rotary stiffness and the maximum rotary angle response of the column base under variable axial force, satisfactorily.

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Cold-formed thin-walled steel members with thicknesses of around 1mm are relatively new structural members in Japan. It is because such a thin steel member had not been long allowed to use as a structural member under the Japanese Building Standard Law. This situation has been changed in recent years through the development of steel-framed houses. Although the use of such a thin steel member is currently possible, there are still some design issues to be clarified for realizing the broader applications, mainly related to its complex buckling behavior. The complex buckling is called distortional buckling and is often seen in the floor and roof panels in steel-framed houses. To study the behavior of distortional buckling in detail therefore, negative bending tests were conducted in this paper for panels consisting of two lipped-channels and structural plywood fastened together with screws. Twelve bending tests provided detailed behavioral information on distortional buckling and the possible strength evaluation methods for improving the design of thin-walled steel members.

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This paper presents the results of experimental studies concerning the moment carrying capacity of steel wide flange beams subjected to cyclic bending. Beam specimens were dynamically loaded in various loading sequences under the condition that local and lateral bucklings and connection fractures were effectively prevented. The major findings obtained from these tests are as follows: 1) the bending moment carried by beams increases during the initial three cycles under constant displacement amplitude, and subsequently reaches the upper limit. 2) the possible maximum moment capacities are obtained for both short and normal beams, and 3) flexural strength demands for beam-to-column connections can be evaluated taking into account deformation amplitude and the number of excursions during the earthquake response.

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In order to design RHS (rectangular hollow section) column-to-H beam connection with split-T stubs, out-of-plane deformation of column plate should be considered, which causes semi-rigidity of the connection. Estimation of yield and ultimate strengths of the connection is derived from plastic analysis by assuming yield and collapse mechanisms concerning out-of-plane deformation of the column skin plate and stretch of the high-strength bolts. The assumed mechanisms and analytical estimation of strengths of the connection are verified by finite element analysis. The analytical estimation of strengths is also verified by comparing with the results of previous experimental studies by tensile tests of the connection.

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The flexural behavior of concrete filled square steel tubular (CFT) columns using high strength materials is experimentally investigated. Tests are carried out on sixteen CFT specimens subjected to uniform bending under a constant axial load. The experimental load-deformation curves are compared with analytical curves using our proposed stress-strain relationships. On the bases of the comparisons, a simple calculating method for flexural capacities of high strength square CFT columns is proposed. One of the features of our calculating method is that the applicable ranges are wide for material strengths and width-to-wall thickness ratio of CFT columns. The ranges of the concrete strength and the yield stress of steel tube are from 18.6 (MPa) to 119 (MPa) and from 194 (MPa) to 781 (MPa), respectively. The range of the width-to-wall thickness ratio of CFT column is from 22.7 to 98.0. The proposed calculating method is calibrated by the total of sixty-two experimental capacities.

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Local buckling of concrete filled steel tube column (CFT column) is analyzed on the upper bound theorem of the limit analysis. The collapse mechanism of the analysis is assumed on the basis of CFT column test under monotonic and repeated load. The load deformation relations of many CFT columns designed under quite different conditions are calculated by the proposed analysis method. The plastic deformation capacity until the local buckling of CFT column which is closely related to the crack of steel tube is also obtained by it. From the calculated results it is shown that the local buckling of CFT column is significantly effected not only by the well known diameter to thickness ratio of steel tube but also by the axial force ratio, the aspect ratio and the strength ratio of concrete to steel tube.

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Following the amendment of Japanese building standard, the concept of performance-based design was introduced. The previous design standard is still employed as the basic one though it may bring the insufficient seismic performance, if buildings are designed just to reduce the initial cost. In this paper, the seismic performance of buildings was determined from the viewpoint of minimizing the life cycle cost, considering the risk transfer by insurance or other financial techniques. A portfolio consisting of 25 buildings in the Kanto district was employed in the analysis. Through the application, the following findings were obtained; combination of risk control and risk finance reduces the life cycle cost significantly, life time has a large effect on the selection of risk management scheme, and the trend of risk aversion has also a effect on the selection of risk transfer techniques.

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The Distinct Element Method is one of the most appropriate tools to simulate discontinuous media. We try to use this method to analyze the problem in a huge coal silo (46m-wide). 200,000 particles are used to simulate the behavior of coal. The simulated results agree well with the measurements and the design. Especially, the arch area shown by the simulation is similar to the one assumed from the result of the measurement. There are several limitations to apply the OEM to the practical model, but it is indicated that the OEM is very effective to show the behavior of the particles in silos.

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Discussed items are summarized as follows. 1 The authors mention to the total energy input very simply. Do authors intend to insist on the ineffectiveness of the total energy input in estimating maximum deformation? 2 Is it theoretically true or simply conventional to consider that the maximum deformation is governed by the instantaneous energy input? 3 The reduction to the one-degree of freedom system does not claim the possibility of the equivalent linearization method but expresses only its limitation in dealing with damage distribution. Is it true or not? 4 The maximum deformation is one of important responses. But, why do the authors adhere to the maximum deformation so strongly on the sacrifice of true understanding of the energy balance?

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The answers are summarized as follows: 1. In estimating maximum deformation, the total energy input is one of the approximate methods based on energy balance. 2. The authors did not use the concept of instantaneous energy input. In estimating maximum deformation, the instantaneous energy input cannot avoid to be assumed value. 3. In reducing one-degree freedom system, damage distribution is presupposed, but it does not become practical limitation of applicability of equivalent linearization method, because the mechanism confirmation is indispensable in seismic design of building structure. 4. It is considered that the design criteria should not be the value, which has advantage in estimating the response by energy balance, but the value, which describe the limit states of building structure appropriately. From the practical standpoint, the authors consider that the maximum deformation is most appropriate value, which define the limit states of building structure.

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