The precast concrete member is steam-cured in the production process. In addition, the large-size precast concrete column is cured under high-temperature condition in early ages by internal storage of the heat of cement hydration. These temperature rises of concrete are numerically predicted using the mathematical model for cement hydration and microstructure formation. C₃S, C₂S, C₃A and C₄AF hydrations are calculated in the model. The influences of sensible heat and latent heat are simulated in the model. The predicted concrete temperatures are compared with the measured precast concrete temperatures. The model proposed in this study is useful for predicting the temperature rise of precast concrete member.

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 A new method topredict a long-period ground motion due to arbitrary seismic source was developed. In the method, the ground motion due to an earthquake is generated from the ground motion record due to other earthquake by using the transfer function defined as the spectral ratio between the theoretical ground motions due to each earthquake. The theoretical ground motions are simulated based on a soil structure model by 3D finite difference method. In addition, a technique to compute the Green’s functions giving the ground motions at a station by arbitrary seismic sources based on the reciprocity theorem is used in order to reduce calculation load. Applying the new method to three earthquakes, it was suggested that the ground motion record of a small earthquake is accurately scaled up to that of a large earthquake.

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 We propose a method to infer the Green's functions (impulse response) of torsionally coupled shear buildings from array microtremor recordings on the basement and on an individual floor for the identification of mechanical and modal parameters as well as computation of seismic responses. Vibration of n multistory torsionally coupled building is modeled as n 3-input-3-output linear systems. The Green's tensor (Green's functions) is obtained by solving a simultaneous linear equation, where the coefficient matrix is composed of the correlations between input motions, two translational and one rotational motions, and the coefficient vector is composed of the correlations between the input and the output motions. We also propose a simple method to remove low-frequency noises from the Green's functions associated with input rotational motion. Applying the method to an existing building, we examine the reliability of the inferred Green tensor in time domain and in frequency domain. It results in that the three diagonal Green's functions are reliable ones but same off-diagonal Green's functions are slightly worse. However, the Green's tensor reproduces the observed microtremor recordings, indicating that the Green's tensor is reliable. This also indicates that the inferred Green's tensor is usable to indentify the parameters.

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 Viscous mass dampers with friction origin force restriction mechanism are considered for base isolated structures. From a series of analytical studies, these viscous mass dampers can reduce the displacement of the base isolation layer, but they cannot reduce the floor response acceleration of the superstructure depending on the input ground motions. To improve the damper, viscous mass dampers with bingham fluid origin force restriction is suggested. The suggested damper can reduce the floor response acceleration compared to the previous dampers for several input ground motions. The difference of the response for both dampers is considered from the time history analysis and response spectra. It is cleared that the suggested damper had better performance for the isolation effect compared to the viscous mass dampers with friction origin force restriction mechanism and the conventional oil dampers.

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 This paper shows a design method for a PD controller, which is utilized as a tool for position control to operate an auxiliary mass of an active mass damper system having a neural oscillator. Because the PD controller must have a roll not only to operate the auxiliary mass to the aimed position, but also to dissipate vibration energy of the structure, the ordinary design method can not apply to design the controller. This paper proposes a new theoretical design method for the gains of the PD controller in consideration of dissipating vibration energy of the structure.

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 The ultimate bearing capacity (q_p) estimated by SPT N-value (N) for cast-in-place concrete piles supported by cohesionless soils was investigated by analyzing the published vertical loading test results. Following findings were obtained. (i) It is better to separate the effects of the confining stress and soil density on both q_p and N. (ii) It is more rational to classify the cohesionless bearing stratum into sandy soils and gravelly soils in estimating their bearing capacity. (iii) A q_p/σ_v’–N₁ correlation based on the Terzaghi's theory well fits to the vertical loading test results for both sandy and gravelly soils where N₁ is a normalized SPT N-value by the effective overburden stress (σ_v’). The q_p/σ_v’–N₁ correlation is better than q_p–N correlation. (iv) By modifying the Yamaguchi's theory, a q_p/σ_v0’^0.75–N₁ correlation derived in the present study shows better fit to the results of vertical loading test of cast-in-place concrete piles supported by both sandy and gravelly soils.

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 The authors conducted the pull-out loading tests on a helical screw pile in a calibration chamber where the two layered sand deposits with different relative densities were prepared. When the ultimate uplift resistance of the pile head occurs, the uplift displacement is equal to 7.5~10% of the diameter of the helical plate. Meanwhile, the helical plate, the bottom plate and the pile shaft forming the helical screw pile show the particular resistance-displacement curves. The helical plate resistance definitely increases with the embedment length while the bottom plate resistance beneath the helical plate tends to be nearly constant.

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 In order to evaluate the bearing capacity of screwed pile with spiral wings, four full-scale pile load tests including axial compression and uplift tests in sand & clay deposits were carried out. We focused on the installation torque and shaft resistance of the piles, and obtained the following conclusions.
 (1) The shaft resistance of the pile can be determined by the shear strength of cylindrical surface whose diameter is D_w,
 (2) There is a fairly-well defined correlation between shaft resistance and installation torque even in real ground, and
 (3) The shaft resistance of this pile can be estimated using the installation torque.

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 Experiments were conducted on ten reinforced concrete beams arranging second layer-cutoff bars to study the influence of the bond reinforcement upon bond splitting strength or anchorage behaviors. The longitudinal bars of beams were reinforced by transverse bars having different configurations (separated and closed types) and strengths (σ_y=295 and 1275 N/mm²). The bond strength of the second layer bars reinforced by separated type bars was almost equal to that reinforced by closed type bars. High strength bond reinforcement increased in bond strength by 30 %. Test results also showed that the bond strength of the second layer-cutoff bars were considerably higher than calculated value according to design guidelines of AIJ. A new reduction coefficient for the second layer-cutoff bars was proposed to reasonably estimate the bond strength for anchorage failure.

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 The effective slenderness ratio of light gauge built-up compression member is following the formula proposed for heavy sections; however, it is not verified that it can be adopted in light gauge. In this paper, full scale testing of light gauge built-up members are conducted. From the test results, it is shown that current Standard overestimates the buckling strength. Based on energy equilibrium theory, modified effective slenderness ratio for light gauge built-up member is derived. The validity of the proposed formula is shown by test results and parametric finite element analysis results.

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 This paper presents the arrangement method of lateral bracings which effectively restrains on out-of-plane deformation. Authors have proposed method that bracings are located near plastic hinge and the remainder as equal distance of l_b/i_y≦100. Beam with proposed lateral bracings maintained sufficient strength under cyclic loading. However, the large out-of-plane deformation is caused. In the proposed method, four lateral bracings are located at the position with each beam-ends and the remainder as equal distance of l_b/i_y≦140. The method is easy to determine layout of lateral bracings, maintains strength and restrains out-of-plane deformation.

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 Recently, elasto-plastic analysis of a large-scale complex frame is easily conducted, by the development of computer technology. But, efforts to decrease the number of unknowns are also necessary, for time-history response analysis or thermo elasto-plastic analysis of large-scale structures. In this study, theoretical investigations are presented here on the structural behavior of steel frames with and without braces, subjected to repeated static loading or extended temperature. Under the assumptions that curvature distributions are almost proportional as the virgin loading, even at the repeated loading, computed results of the present analysis show a good agreements with the precise finite element solutions.

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 This paper proposes a new simple model for a load-displacement relation for predicting the local tensile elasto-plastic behavior of concrete-filled square steel tube column to steel beam eccentric moment connections using internal diaphragms or internal diaphragms with extended flanges. This model is developed by replacing two models of central moment connections. The central model proposed by the writer is provided by superposing the load-deformation relations of a tube flange and web. The tube flange is modeled as a grid beam with a tetra-linear load-deformation relation, while the tube web is modeled as a tensile member with a tetra-linear load-deformation relation. The strength of the internal diaphragm is superposed to the strength of these tube load-deformation models. Analytical results agree approximately with experimental results up to large deformations.

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 In this paper, practical optimal design method is proposed based on genetic algorithm for determining placement and cross-section of bearing wall, beam and horizontal brace of steel residential house. Employed building system has discrete choices for member sections, and member placement at 150mm unit. With this system, rational design is required in high design freedom. Especially, it is difficult to determine beam placement because of complicated constraints on the beam placement around a stairwell or under a roof strut. However, few methods have been proposed considering such problems. The objective of this paper is to obtain practical solution in realistic time considering design constraints for various building plans.

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