The authors have carried out full-scale measurements on a high-rise building to obtain data for wind resistant design of claddings. Characteristics of mean wind-induced internal pressures were reported in the previous paper (Part1). The present paper describes the fluctuating wind-induced internal pressures measured on 17th Sep. 1995 and 22nd Sep.1996 when typhoons hit the Kanto area. There was a peak in the power spectral density of the fluctuating wind-induced internal pressures at lower frequency than that of the wind pressures measured at the top of the building. The power spectral density of wind-induced internal pressures decreased sharply over 0.06Hz because of the filter effects caused by leakage pass. The coefficients of fluctuating wind-induced internal pressures were about 0.05 and the peak coefficients were about -0.4. These values are smaller than ones recommended by A.I.J.

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We conducted a series of shaking table tests on non-linear soil-pile-building interaction system in order to investigate effects on plastic deformation of soils to the interaction system. A simplified method to estimate maximum moment of piles was applied to results of the tests. The results shows as follows ; 1. Effect of bending moment of piles caused by the ground deformation became large by plastic deformation of soils. 2. The simplified method well estimated the maximum bending moment of piles when maximum acceleration of input motion was from about 100 to 300gal.

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This paper presents a design method for controlling vibration of multi-degree-of-freedom structure with semicircular curved linear-motor device for absorbing vibration. The control theory using output regulation with internal stability applied in designing the system subjected to artificial wind force or artificial earthquake ground motions. The numerical results of computer simulations of the system show excellent effects of the control and shaking table tests of three story steel structured model of the system verify realizability of the simulations.

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This paper first shows that, in elastic-plastic seismic responses of low- and medium-rise framed structurtes, horizontal displacements of the top of the structures can be approximately estimated by the 1st mode solutions previously presented by the author, but that, as for rotation angles of plastic hinges, errors of the 1st mode solutions are not small. Secondly, an approximate method using the top displacements of the 1st mode solutions of the seismic responses and hinge rotation angles of precise solutions of elastic-plastic impulse responses is proposed, which improves the errors remarkably.

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The 1995 Hyogo-ken Nanbu earthquake struck Kobe and adjacent cities, one of the most densely populated area in western Japan, and killed more than 6,400 people and destroyed more than 150,000 buildings and houses and tens of highway and railroad bridges. It is very important to examine the ground motion characteristics in the severely damaged area during the mainshock for understanding how buildings and bridges performed and why they reached collapse. Unfortunately very few strong ground motions were recorded in the severely damaged areas during the mainshock. In this study, we attempt to estimate ground motion at severely damaged sites by using the empirical Green's function method (EGF method). We derive a best source model with three asperities after several try and error with forward modeling by the EGF method. We estimate strong ground motions at sites, where the mainshock was not recorded, using aftershock records. The synthesized motions in the near-fault region in Kobe were characterized by two large long-period (1 to 3 seconds) pulses due to the forward rupture directivity. Peak horizontal acceleration and velocity of the synthesized motions at the heavily damaged sites are about 1,000 cm/sec^2 and 130 cm/sec, respectively, while those at a rock site in near-fault region show about 300 cm/sec^2 and 60 cm/sec. The reason why so strong motions hit the heavily damaged sites is that the large long-period pulses which come from two asperities in the Kobe-side segment of the fault were further amplified by the basin edge effects.

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The nonlinear random response of soil-column subjected to non-white excitation is dealt with. The formulation is based on the stochastic linearization method developed by Atalik and Utku, and the nonlinear hysteretic characteristic of soil is approximated by Wen's model. And its parameter is determined to simulate Ohsaki-Hara model in the prescribed strain range. The numerical method to deal with the arbitrary non-white excitation is also presented. In this method, the autocorrelation of input motion is used as the input of the derivative equation, and the external load term of covariance derivative matrix equation is given by the numerical solution of the vector derivative equation. This method is especially effective when it is difficult to find the linear filter equivalent to the target spectrum. The solutions are compared and well agree with the results of Monte-Carlo simulation.

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The paper deals with a vibration control system consisting of vsico-elastic dampers (VEDs) and an active-tuned-mass-damper (ATMD). The VEDs are installed to each story, while the ATMD is placed on only the tqp floor. The ATMD is based on the acceleration feedback method, the optimal tuning condition of which is derived numerically. The emphasis is placed on the application of the system to the elasto-plastic structure subjected to strong ground motion. We found that the proposed system not only decreases the damage of a main structure but also improve the control efficiency by reducing the maximum control force and displacement of the ATMD.

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The purpose of this paper is to study the dynamic buckling behaviors under the influence of static pressure loads for shallow spherical caps subjected to cyclic pressure loads. The numerical research showed that the dynamic buckling mechanism is classified three categories concerning the minimum dynamic buckling loads in cyclic pressure loads with different frequency, and in three domains the minimum dynamic buckling loads decline almost linearly in proportion to the static loads. In the first domain the dynamic buckling loads indicate a gentle decrease and high values, and the buckling mechanism shows the sharp increase of the deformations without jump phenomena. In the second domain the buckling loads decline sharply and there are two dynamic buckling mechanisms, types of the jump and no jump phenomena. In the third domain, no capacity for resisting dynamic loads can be expected because of showing the low value of dynamic buckling loads, and the almost all buckling mechanism shows dynamic jump phenomena.

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Influence of axisymmetrical defficiences in their shell thickness on characteristics of elastic stability of cylindrical shells is discussed. Depth, location and symmetricity with respect to the neutral surface of the shells are the three points which are mainly dealt in this theoretical invetigation. Change in the elastic buckling loads are clearly shown to be closely related to the buckling mode by which cylindrical shells become to be elasticaly unstable. Finite element method by using the axisymmetrical shell element is utilized for formulation of linear eigen value problem by which critical loads and buckling mode are obtained as eigenvalues and eigenvectors, respectively.

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The failure mechanism and ultimate strength of a cylindrical shell roof with vertically supported edge beams are evaluated by stress resultants based on elastic analysis. It is not easy job to analyze the cylindrical shell roof with analytical procedures. Because it is a hard work to analyze cylindrical shell equations. We assume displacement modes of the cylindrical shell in circumferential directions. Applying the modes to the functional of the roof, we evaluate the functional that enables us to get the ordinary differential equations of motion of the system. Adopting the procedure, we analyze the cylindrical shell roof models and show displacements and stress resultants of static behavior, which are compared with the values obtained by analytical procedures. The procedure lets us to get natural frequencies of the roof.

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CFRP (Carbon Fiber Reinforced Plastics) sheet has been used for the retrofitting of a number of existing concrete buildings and structures because of its excellent properties (high strength, lightness and high durability). To be an effective retrofitting system, however, bond effectiveness between CFRP sheet and concrete should be verified, and understanding of the peeling mechanism is especially important. This study employed both the experimental and the analytical methods to quantify the maximum bond stress τ_y and the effective bond length l_u, where the bond stress distributes. Here the interface is modeled as an interphase of 1 mm thickness, that is, a composite which consists of epoxy resin and concrete. The values of τ_y and l_u are finally proposed, and they are 4.56MPa and 45.2mm, respectively.

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This paper summarizes test results and discusses the elastoplastic behavior, such as lateral strength, ductility and energy absorption capacity, of doubly confined R/C column in steel tube and hoops. The experimental results are compared with the theoretical results. The experimental results have conducted the following remarks. (1) If the amount of transverse reinforcement steel is almost the same, the double confinement method by steel tube and hoops will be superior to the single confinement method by steel tube only on the seismic behavior of the test specimens. (2) The double confinement requires higher strength concrete in order to enhance seismic performance for columns. According to the calculation results, the higher concrete strength is desired to be at least over 30 MPa in cylinder strength of the concrete. This suggestion is approved through the experimental test.

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The welded girders of cranes with high loading cycles develop cracks in the welds on upper flange and/or lower flange. It needs the maintenance and periodical inspection to keep the safety of crane service. This paper showed the method of damage level evaluation of welded crane runway girders, especially in iron works using artificial neural network, and showed the important factors which contribute to the damages on crane girders by sensitivity analysis. The damage evaluation for 20 examples using this system showed the satisfactory results on the decision concerning fatigue crack occurred or not. And the results of the sensitivity analysis showed that the damages in the vicinity of the upper flange were influenced by the kind of cranes, maximum wheel load, and the product of used years and frequency of use, and damages in the lower flange were influenced by runway girder span, and the product of used years and frequency of use.

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In this paper, inelastic flexural behavior of concrete filled circular steel tubular columns is described. In order to obtain the flexural behavior more accurately, uniform bending tests were conducted in wide range of axial load ratio by using thirteen specimens, half of which were annealed to remove residual stresses, including two hollow tube specimens. Analytical methods for estimating bending moment capacity and moment-curvature relationships with taking account of confinement effects between steel tube and infilled concrete are proposed. Comparing the analytical results with the experimental results, influence of the confinement effects and residual stresses in steel tube on the flexural behavior is discussed.

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This paper reports bending shear test result of centrifugal concrete filled steel tubular column using super high strength concrete. The concrete is cast by cenrifugal spining method using super high strength concrete, and the concrete portion has a vacant hole. The evaluation formula of compression strength of consideration for confining effect derived from the results of axial compression test by authors. In this paper, the bending shear test under axial force of the column specimens were caried out in order that we may confirm relation between a vacant hole and structual performance. We proposed ultimate bending strength of consideration for confining effect of concrete filled steel tubular column can be estimated by proposed formula.

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This study is to investigate the failure mechanism of local buckling in steel bridge piers caused by the 1995 Hyogoken-Nanbu Earthquake. The impact loading test was done to examine the possibility of producing local buckling in steel pipe specimens by an impulsive force. Six types of steel pipes with circular and rectangular cross section were employed for tests. Axial impact load was input to a specimen by means of a horizontal impact loading machine.

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The System Truss Design Standards which offer a selection of standardized component are utilized for the design of a system truss. However, individual judgement is also required in the economic and construction aspects. For example, the economic aspects, structural properties and the construction method become even clearer by a quantitative comparative study of the performance data based on actual projects of a system truss. This paper statistically analyzes the design and construction information which stipulates the capacity of a system truss, and provides basic data in order to appropriately evaluate the design conditions and to determine the rationality of construction of a system truss.

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The generalized conjugate gradient method (the GCG method) for symmetric coefficient matrices needs less memories than the direct methods for the solution of linear equations with banded or skylined matrices and is able to check the singularity of matrices. In this paper, the condition number, the relative residual norm, the convergency and the computing time regarding the GCG method and the skylined method by numerical simulations for the non-linear model of plane and space frames are given. The results of numerical simulations show that the GCG method is practical alternative to direct methods in the solution of large sparse systems of equations by the accuracy and stability of this method.

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