The measurement method of electromagnetic wave absorption in the VHP band (80-230MHz) and the quasi microwave band (1700-2600MHz) has developed by the parallel wire line method. In this paper, the measurement method of the transmitted coefficient and the reflection coefficient is developed by the parallel wire line in the UHF band (400-800MHz). These coefficients are calculated from the standing wave ratio on the parallel wire lines. The transmitted coefficient is measured by the phase shifter. The accuracy of the phase modulation is measured by using a network analyzer.

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Generally, the slip resistance of floors is keeping up suitable value. But sometimes its become dangerous, because of changing the slip resistance caused from abrasion. In this study, the relationships are investigated between the change of slip resistances to abrasion. And from the exact observation of the human being walking, it was investigated that the abrasion are caused mainly from the rubbing by shoes. From these results, the outline of the speedy estimation method for change of the slip resistance is considered, with the advanced measuring method of slip resistance and the newly developed accelerating abrasion machine in this future study.

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This paper presents the efficient evaluation method of slipperiness of wet floors with bare feet. The first, sensory test to obtain the sense of slipperiness of sample wet floors with bare feet was carried out to renew the sensory scales, then, C.S.R'・BF (Coefficient of Slip Resistance with Bare Feet) of sample floors were measured dealing with ONO・PPSM (Portable slip meter developed by ONO in former research) and the newly developed slider in this research. The second, we carried out sensory test, to make the evaluation scales of wet floors with bare feet. Finally, considering the relation between the evaluation and C.S.R'・BF, the evaluation index of slipperiness was renewedly generalized.

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A visco-elasto-plastic (VEP) damper that combines in series a visco-elasto device and a friction device shows better performance than either one of the devices. This paper discusses simplified theories on seismic peak response evaluation and preliminary design of the visco-elasto-plastically damped building. They are based on the single-degree-of-freedom (SDOF) idealization of multistory building, and produce the so-called "control performance curve" expressing the peak responses as a function of stiffnesses of all components, based on spectral characteristics of the earthquake. Against the target peak response stipulated, the curve clearly shows necessary stiffness balance between damper and other elements. A rule to convert the SDOF design to multistory design, with a consideration to distribute damper stiffness over the building height, is also presented. Accuracy of the design approach is demonstrated via numerous time history simulations of a wide range of multiple-degrees-of-freedom (MDOF) models.

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A new method to estimate an accurate surface layer model is proposed for hilly area where the data on artificial transformation on ground is not sufficient. This method considers the distribution of surface layers and artificial transformation based on the topographical and geographical features on pre-transformed ground, which are newly evaluated by the aerial photographs on 1930's. Initial model for the 3-D surface layer structure is estimated based on the evaluated high-resolution map of landfill distribution, change of geomorphological land classification, and existing drilling data. Then the Vs profile for each site is revised by the dispersion curves evaluated by the array observation of microtremor. The accuracy of the method is confirmed at the Nagoya University campus by use of the observed seismic records. The presented method is effective for hilly areas where the heavy land transformation has been performed.

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Centrifuge model tests were performed to investigate an effect of foundation girder stiffness on the dynamic characteristics of pile-supported buildings. The results show that the response of a building is influenced by the stiffness of girders. If the girder stiffness is not rigid, the response of a structure and corner piles are less than that of the rigid girder case. An analysis was carried out to simulate the result of a centrifuge model test. In the analysis, a three-dimensional frame model was used. A comparison between experimental and analytical results shows a possibility that this numerical model can be capable of considering the stiffness of girders, and also the soil-pile dynamic interaction effect.

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In this study, a system combined of viscous damper and displacement controller with hardening type force-displacement relationship is proposed. By applying the proposed system to a multi-story structure, displacement controller device restricts the displacement of the all stories and uniform ductility distribution can be obtained, with no significant change in acceleration and inertia force values. Moreover, an energy-based damper design method, with the assumption of uniform ductility distribution, is proposed to determine the necessary viscous damping coefficient and the adequate gap of displacement controller. The results show that, seismic displacement response of the reinforced concrete multi-story structure is effectively reduced under the target ductility value, with the viscous damping coefficient that is obtained by the proposed method.

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The seismic stability of multi-story structures can be characterized by an instantaneous material stiffness coefficient that represents the effect of material yielding and an instantaneous geometric coefficient that represents the effect of geometric nonlinearity (P-Δ effects). These terms, when added together, define a net stability coefficient that is related to the instantaneous eigenvalue of the structure and quantifies the susceptibility of a structure to exhibit large deformations under earthquake loading. The results of nonlinear dynamic analyses of a nine-story steel frame are used to evaluate the proposed stability coefficients as well as previously proposed methods for assessing structural stability. Data show that under earthquake loading the instantaneous material stiffness coefficient decreases due to material inelasticity while the instantaneous geometric coefficient generally increases due to the development of drift concentrations. Also data show that the column continuity has the large impacts on the structural stability and hence drift response.

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Probabilistic evaluation of the seismic performance of 3D steel moment-frame structures is carried out for two types of framing system: two-way frames typical of construction in Japan and one-way frames typical of construction in the United States. For each framing system, four types of beam-column connections are considered: Pre-Northridge Welded-Flange-Bolted-Web, Post-Northridge Welded-Flange-Welded-Web, Reduced-Beam-Section, and Bolted-Flange-Plate connections. A suite of earthquake ground motions is used to compute the annual probability of exceedence (APE) for a series of drift demand levels and for member plastic-rotation capacity. Results are compared for the different framing systems and connection details. The two-way frames have a smaller APE for small drift demands for which members exhibit no or minimum yielding, but have a larger APE for large drift demands for which members exhibit large plastic rotations. However, the one-way frames, which typically comprise a few seismic frames with large-sized members that have relatively small rotation capacities, may have a larger APE for member failure.

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The principal purpose of this study is to reduce response displacement and response acceleration to keep higher safety and function against earthquake grand motion that has various characteristics, in particular that contains long period ingredient, for example the future Nankai earthquake. To realize this purpose, using MR-damper whose damping force is variable according to applied electric current, authors conducted shaking table tests to verify the effectiveness of response control of base-isolation system, applied with optimal control theory. This paper shows the effect of changing weighting matrix.

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For the purpose of predicting the large displacement response of isolated buildings, an analytical model for elastomeric seismic isolation bearings is proposed. The model consists of shear and axial springs at mid-height, and a series of axial springs at the top and bottom. The properties of elastomeric bearings vary with the imposed axial stress. At large shear deformations, elastomeric bearings exhibit a hardening behavior under low axial stress and buckling under high axial stress. The properties exhibited depend on the interaction between the horizontal and vertical forces. The proposed model includes the interaction between horizontal and vertical forces, non-linear hysteresis, and dependence on axial stress. To verify the validity of the model, analyses are performed for actual static loading tests of lead-rubber bearings. The results of the analyses show very good agreement with the experimental results.

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Dynamic loading tests on one bay-three story RC frames installing a stud column with a viscoelastic damper are conducted to investigate the dynamic behavior of the frames and the effect of response control by the damper. A total of three frames are tested with different damper arrangement. Influence of the damper arrangement on the damping property and failure mode of the RC frames is discussed. The damping property of the RC frames is also compared with that of steel frames installing a stud column with a viscoelastic damper reported in the previous paper by the authors. It is found that the damage situation of a beam where the damper attaches significantly affects the damping property of the RC frames.

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Simplified theories are proposed for seismic peak response evaluation and preliminary design of buildings with linear as well as nonlinear viscous dampers. They are based on the single-degree-of-freedom (SDOF) idealization of multistory building, and produce the so-called "control performance curve" expressing the peak responses as a function of stiffnesses of all components, based on spectral characteristics of the earthquake. Against the target peak response stipulated, the curve clearly shows necessary stiffness balance between damper and other elements. A rule to convert the SDOF design to multistory design, with a consideration to distribute damper stiffness over the building height, is also presented. Accuracy of the design approach is demonstrated via numerous time history simulations of a wide range of multiple-degrees-of-freedom (MDOF) models.

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The present paper is intended as an examination of a novel method of energy-based estimation of nonlinear dynamic response. The proposed method employs a characteristic curve obtained from the backbone curve of nonlinear dynamic system, and can be expected to give approximate energy response as a result of superposition of the characteristic curve and the energy response spectrum of acceleration wave. A single-degree-of-freedom system with asymmetric nonlinear restoring force characteristic is discussed as an analytical model. The influence of subharmonic resonance and applicability to seismic response are examined in detail through the numerical integration of the equation of motion.

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The ultimate objective of this study has been to develop a simple model which can evaluate the lateral buckling behavior of the truss beam without using a discrete model. As a preliminary step towards fulfilling this objective, we first recognized the lateral buckling behavior of the truss beam as the out-of-plane buckling behavior of the cord member with axial force gradient. We then presented a numerical method which enables us to conveniently and systematically evaluate the elastoplastic post-buckling behavior of the cord member. However, this method does not take the elastic post-buckling behavior of the cord member into consideration, and hence it cannot be applied to the cord member with slenderness ratio larger than the critical slenderness ratio. Thus, in this paper, we extend this numerical method and present an analytical method that can accurately evaluate the elastic post-buckling behavior of the chord member with axial force gradient.

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Box shear tests are conducted to study lateral resistance phenomenon and its mechanism of the piles running through a slip surface. It is shown that (1) Maximum lateral force increases with higher soil density, higher soil confining stress and more piles; (2) The distribution in depth of the bending moment, shear force and subgrade reaction of the piles depends on soil density, soil confining stress, pile number and pile arrangement; (3) Each stress of front pile is larger than that of rear and middle piles; (4) The effect of pile group efficiency increases with larger horizontal displacement and smaller confining stress.

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The deformation characteristic of a concrete affected by Alkali-Silica reaction is making clear by a lot of studies in laboratories and observations of actual structure. In the case of un-reinforced concrete, these expansion rates affected by Alkali-silica reaction has been able to nearly predict by measuring of residue expansion rate that is tested core sample. Also, it is well known that expansion rate of a reinforced concrete affected by Alkali-silica reaction is come under the influence of constraint of reinforcement. The almost reports of observations for expansion rate affected by Alkali-silica reaction have been ended when expansion rate was saturated. However, some of papers have reported that actual structure has tended to constrict beyond about 15years. This paper considered deformation characteristic of actual reinforced concrete structure affected by Alkali-silica reaction due to measurement of actual expansion rate and residue expansion rate by long term aging phenomena observations beyond 25 years, and it proposed the model of deformation characteristic that is constrained concrete affected by Alkali-silica reaction.

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An efficient linear solver using a multigrid method is developed for solving the pressure Poisson equation. The three-dimensional incompressible viscous fluid flow analysis is performed for investigating dynamic behaviors of a shell roof under strong wind. The improved balancing tensor diffusivity method and fractional step method (IBTD+FS method) combined with the finite element method is used for discretizing the Navier-Stokes equation. In this scheme, the pressure Poisson equation is solved implicitly. Solution process of the equation, which is a large-scale system of linear equations, is the most computationally expensive part. In order to improve the computation speed, a preconditioning technique based on a multigrid method for the conjugate gradient method (CG method) is employed. A simple formulation that combines the diagonal-scaling preconditioner and coarse grid correction is proposed. In addition, a finite element mesh for a two-dimensional analysis is used as a coarse grid for the three-dimensional analysis. The proposed method is implemented in the fluid flow analysis code. Performance study of the proposed method is conducted by solving a number of illustrative examples. Computation speed of the proposed method is much faster than the CG method with a simple diagonal-scaling preconditioner.

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The scheme of computational morphogenesis for the shell structures with free curved surface is proposed, where the requirement on both the aesthetic aspect and the structural rationality can be simultaneously satisfied according to the judgment of the designer. In the proposed scheme, Non Uniform Rational B-Spline (NURBS) is utilized by which the number of unknowns can be controlled while the high degree of freedom for expression of the shape of the curved surface is maintained. For the scale index concerning with the aesthetic aspect, the degree of difference between the curved surfaces given by the designers and those given by computation has been adopted and, on the other hand, the strain energy of the structures has been adopted as the quantitative scale for the mechanical measurement. Consequently, the problem in question has been mathematically formulated as the multi-objective optimization problem, where the optimality conditions are utilized for obtaining the Pareto solutions.

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This study is an arrangement of structure behavior about rolling shear destruction (strength) of wooden panels construction experimentally. The purpose of this study is to define correlativity of plywood shear buckling and shear stress distribution by material experiment, experiment on pint-sized bearing wall, and experiment actual-size bearing wall model. Shearing test of pint-sized bearing wall model showed that shear stress distribution is inequality in the wake of buckling. And, it became clear experimentally that rolling shear bearing force by experiment on actual-size bearing wall is 0.87〜1.11 times as low as by estimated equation of shear strength. There ware defined correlation between shear buckling and shear stress as maximum bearing force by comparing shear stress as maximum bearing force with estimated equation of shear strength.

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Shaking table test for two specimens, consisting of an original vulnerable conventional house and a rehabilitated house, was carried out as shown in the previous paper. They have been in service, moved from the site, and then reconstructed on the table. Original one fell down and rehabilitated one was survived during motion recorded at JR Takatori Station in 1995 Hyogoken-Nanbu Earthquake. In this paper, the results of dynamic seismic diagnosis methods which are able to estimate maximum response against the earthquake are summarized. As the result of comparison of seismic diagnosis and shaking table test, original seismic performance assessment score of 0.43 has high risk of collapse during severe earthquake such as Hyogoken-Nanbu Earthquake and Niigata Chuetsu Earthquake. Through the time-history analysis for past decade earthquakes, seismic performance assessment score of 1.00 has the possibility of collapse, and recent reconnaissance report which means there are no severe damages against over 1G ground acceleration is also verified in this analytical study.

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This paper describes the collapse behavior of new construction of a wood house. The capacity and limit story drift which have not been discussed in past shaking table tests is presented. Repairs were made after seismic test which were conducted before collapse test to return the structural components to their original strength and stiffness. By the comparison in performance before and after repair, rehabilitation after severe earthquake is also discussed. The house survived against two-repetition of JMA Kobe and two-repetition of JR Takatori despite severe damages of finishing and bracing.

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It is well known that lateral confinement reinforcement of the confined concrete is very useful in order to improve ductility for R/C columns. Already, many analytical researches have been reported and proposed by various researchers. However, up to the present, many researchers have been hardly evaluated the effect of longitudinal bar on the compressive behavior of confined concrete. The purpose of this paper is to investigate the effects of compressive strength and compressive ductility for the arrangement of longitudinal bar. The main variables are arrangement of longitudinal bar. The authors obtained the factor of amount of longitudinal bar which considered arrangement of longitudinal and transverse bars. As a test results, the compressive strength increased linearly in proportion to the amount of longitudinal bar by the arch action formed among longitudinal bars until buckling of the longitudinal bar occurred. Also, the decrease in compressive ductility due to buckling was more prominent for large amount of longitudinal bar. Furthermore, taking into account the effects of these factors, the equation for compressive strength and the stress-strain curves of confined concrete were proposed on the basis of the test results.

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Ultra-high-strength concrete more than 100 N/mm^2 has been required for reinforced concrete (RC) columns in the lower layer of super high-rise condominiums. The configuration of a crack in such a high-strength concrete is much smoother than that in normal-strength concrete. This smooth crack surface may lead different mechanical behaviors of RC members. The tests were performed on RC member with compressive strength of 125 N/mm^2 to study the influence of the configuration of cracks and the arrangement of shear reinforcement upon the shear behaviors of RC members. The meaningful relation between shear reinforcements and shear crack behaviors has been proven by measuring the width and sliding of cracks. The FEM analyses have been also carried out to investigate the shear transfer mechanism in smooth cracks by using smeared crack models with shear retention factors and discrete crack models with different aggregate sizes.

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It was attempted to present a method to quantitatively evaluate damages to R/C shear columns subjected to earthquake loads in the post-peak region including collapse. The method that uses the post-peak load-deflection relations formulated based on test results and assumes the concept of the failure surface contraction following shear failure, enables us to compute how much residual lateral- and vertical-load carrying capacities of columns are when they undergo a given level of lateral drift. Those capacities are computed using lateral and vertical reinforcement ratios and axial load ratio.

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Limit-state strengths of I-shaped structural steel members at elevated temperatures are analytically investigated by using detailed finite shell element models. Elastic and inelastic flexural buckling and lateral-torsional buckling are simulated for the limit-states of columns and unbraced beams, respectively. The simulations are conducted using steel design properties at elevated temperatures described in Recommendation for Fire Resistant Design of Steel Structures and Eurocode 3, which are compared with existing test data by several researchers. Pursuing realistic and practical evaluation of structural performance, equations for column and unbraced beam strengths are proposed as functions of elevated temperatures and member length. The proposed strengths agree well with the simulation data using the steel properties from Eurocode 3, which are more representative of the test data. This member-based strength evaluation is expected for use as an alternative simple design approach for future limit-state design in structural fire engineering.

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According to the author's past experimental studies, performance of buckling-restrained braces using mortar planks depends on the index that Euler's buckling load of a restraining part is divided by the yield load of a core plate. When the index of restraining effect is more than 1.0, the strength of the buckling-restrained brace does not decline until one percent strain equivalent to 1/100 story drift angle. This is the experimental result, but, the meaning of the index of restraining effect is not confirmed by an analytical approach. And the core plates shape into high-order buckling mode at the maximum load-bearing capacity of the buckling-restrained braces. It is also necessary to analyze how such buckling behavior proceeds. Referring to knowledge of the past experimental results, the authors conducted finite element analysis considering elasto-plasticity and large deformation. The index of restraining effect indicated the same meaning for not only the experimental results but the analytical results. And also the analytical results confirmed that when load increased, first, the core plate shaped into first-order mode, then, it changed to high-order mode gradually.

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In this paper, the fatigue strength of high strength bolts which are improved to have more high fatigue strengh than convensional high strength bolts is described. The difference of thread pitch between bolt and nut, the bolt strength and the time on roll forming of bolt thread are taken as test parameters. And from the test results, the results of considering on the influence that these test parameters give to fatigue strength are described.

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This paper proposes design formulae for RHS-column to beam connections with exterior diaphragms. In Ref. 7), full plastic strength and ultimate strength were obtained by applying plastic analysis to the collapse mechanism, which consists of yield lines on the column tube wall and three yield zones of the exterior diaphragm under uniform strain condition. In this paper, yield strength and ultimate strength are derived based on some informations obtained by plastic analysis. Next, approximate formulae for evaluating the yield strength and the ultimate strength of the connections are proposed in order to make the method proposed above more practical. Finally, the design method of fillet welded connections between the column tube wall and the exterior diaphragms is proposed, too.

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This paper discusses the hysteresis curve and the limit rotation angle of SRC columns composed of unembedded type column bases under axial tensile force. In the beginning, we describe the mechanical model to carrying out the elasto-plastic analysis. It had been reported in the previous paper that the mechanical model is accurate, but we tried to improve the accuracy of the mechanical model further. Then, in order to discuss the hysteresis curve and the limit rotation angle of column bases, we carried out the numerical analysis by the mechanical model. From the analytical results, an effective way to increase the deformation capacity of column bases were became clear, and we presented the appropriate design method about each column of the first floor in SRC structures.

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The shear slip failure of unenbedded type column bases in SRC structures were reported by Hyogoken-Nanbu earthquake and the experimental research in recent years. However, there has been no study that tried to evaluate ultimate shear strength of unenbedded type column bases. We describe the structual test carried out in order to study ultimate shear strength and hysteresis property of unenbedded type column bases. Structural test made it clear that mechanical property depends on the axial force level, and the anchor bolts is not valid for ultimate shear strength. We proposed the evaluation method of ultimate shear strength. Ultimate shear strength of column base is calculate by applying the superposed strength method, in which the ultimate shear strength of the anchor bolts and friction between the base plate and the concrete below the base plate is taken to be the sum of the punching shear strength of the RC portion surrounding the base plate. Proposed evaluation method of untimate shear strength is in accordance with the test result well.

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