In the present study, the volume change in the early age for blast furnace slag cement and the mortar of blast furnace slag cement mixed with a lime-based expansive admixture was investigated based on different temperature histories. When extracting lime, the expansive admixture is consuming quite amount of water, and an influence of the self-desiccation is excelled, hence the thermal expansion is rapidly increased. However, the lime-based expansive admixture showed the desirable results that only an expansion tendency was preserved without the effects of shrinkage, similar to the results of no-mixtures. The compensation of autogenously shrinkage due to expansive admixture is strongly affected by temperatures of mixed mortar, and, in the scope of this study, the least compensation effects were confirmed at the temperature of mixed mortar, 20°C, among 10°C, 20°C and 30°C.

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 Pressure distribution in waterproofing system with air-permeable layer was studied considering the number and the position of an exhaust apparatus. Three test specimens in which an exhaust apparatus is placed at different positions in the membrane were applied on a PVC substrate with many holes. Compressed air was supplied through the holes and the pressures behind the membrane were measured. The pressure was kept at low levels for all the specimens with air-permeable layer. The number of an exhaust apparatus and its positions gave much influence pressure distribution behind the membrane too. The same results were also obtained through the numerical analysis.

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 In this study, for the purpose of improvement of estimation accuracy for compressive strength of concrete by ultrasonic method, a measurement method for ultrasonic velocity and a strength estimation method for concrete are investigated. The precision of the developed method for measuring ultrasonic velocity by inserting two probes into the small holes drilled in concrete in structure was confirmed to be high. Further, a method for estimating compressive strength of concrete from ultrasonic velocity through Young's modulus in consideration of the influence of materials was proposed.

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 Although rubber bearings are popular for seismic isolation bearings in Japan, Spherical Sliding Bearings (SSB) or Friction Pendulum Bearings (FPB) are also widely used in many countries including U. S. In this paper, shaking table tests on braced frame supported by SSB are carried out, and their dependency on pressure and velocity is examined. Also tests with the eccentric dead loads are conduted, in order to capture lift-up actions at bearings and their performance. Analytical models taking pressure and velocity dependency into accounts are proposed, and their validity against the experimental results are discussed.

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 A tuned mass damper-like system can be constructed by arranging a two-node mechanical mass device, referred to as an inerter or a dynamic mass, that generates inertial resistance forces proportional to the relative accelerations between its two nodes with a viscous element in parallel and spring element in series arrangement. The present system is referred to as the tuned viscous mass damper (TVMD) seismic control system. When TVMDs are incorporated into a building structure subjected to strong ground motions, components of the inter-story motions resonant to the additional system result in amplified motions and substantial energydissipation in the viscous element. For a multi-degree-of-freedom(MDOF) systema closed formoptimumdesign is obtained from equivalent single-degree-of-freedom reduction using the fundamental mode of an uncontrolled system if the apparent mass distribution of the dampers is proportional to that of the primary stiffnesses. The optimum design, however, does not apply to a system in which the distribution of the supplemental masses is non-proportional to that of the primary stiffnesses. Thus, the main objective of this paper is to discuss the optimum control method and characteristics of an MDOF seismic control systemhaving non-proportionally distributed TVMDs.

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 It is important to investigate the effect of the uncertainty of the condition of a fault model to the results of the ground motion prediction for scenario earthquake. In such investigation, many case studies of the ground motion prediction are required. In order to calculate the ground motions efficiently, we proposed the simple evaluation method of seismic response spectrum using a fault model. The proposed method using the simplification which assumed the random vibration can obtain easier the mean response spectrum than the calculation of a large number sample by the statistical Green's function method.
 Then, the effect of the uncertainty of the fault parameters to the result of the ground motion prediction for the scenario earthquake was investigated by the simulation based on many samples of fault model using the proposed method. Although the spatial distribution of the mean response spectrum was simple, the standard deviation of response spectrum showed complex spatial distribution. The standard deviation of response spectrum was large near a fault edge and at the points on the extension of a fault strike. Since the variability of the predicted response spectrum changes with locations of a calculation point, when evaluating the seismic hazard in consideration of the uncertainty of the fault parameters for the scenario earthquake, it is necessary to scrutinize the effect of the uncertainty for every target calculation point.

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 This paper proposes the method to reduce the MDOF system to the equivalent SDOF system for low-rise steel structures with a flexible roof. The target structure has two braced frames and some moment resisting frames. Evaluation methods of the maximum seismic forces acting on frames are presented with dimensionless parameters. The envelope curve and the equivalent damping ratio of the SDOF system is formulated. It is confirmed that the roof deformation potentially magnify the maximum ductility factor at the side braced frame. Finally, the maximum elasto-plastic responses are predicted based on the response spectrum method.

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 FRP blocks are effectively used for reduction of cost and period of time for seismic retrofit of building frames, because they can be manufactured in plants and attached to the existing frame easily. However, in the current process of retrofit, the effect of installing blocks on the forces in the existing frame is not appropriately considered. In this study, a shape optimization approach is presented for improving mechanical property and reducing the section forces of existing frame members. The existing beams, columns, and the members in latticed blocks are modeled using beam elements, and the contact between members are evaluated using the penalty approach. It is shown that various shapes can be generated by solving nonlinear programming problems considering structural weight of latticed blocks, horizontal stiffness of the frame, and the shear forces of the existing beam.

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 Authors have proposed macroscopic elasto-plasticity analytic model¹⁾, limit-analysis model²⁾, and simplified model³⁾ as evaluation modelings of maximum strength of isolated reinforced-concrete framed shear walls. These models have the feature to use the stress of columns and beams surrounding a wall panel for calculation of maximum strength of framed share walls. Then, this study evaluates shear strength of columns and beams of framed share walls from experimental results by applying the simplified model. And, the following equation was drawn as an expression of those relations.
 τ_u= 0.135σ + 0.805p_w·_wσ_y+ 0.059σ_B

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 This study investigates initial stresses induced in the RC column made of high strength concrete during the early age using 3-D finite element analysis including in time-dependent behavior of concrete. First, the temperature profile inside the column is calculated by the thermal conductivity analysis, and the corresponding thermal strains are obtained. For reconciling the computational cost and accuracy, the double power law is applied to prediction of the creep strains. Furthermore, the linear expansion coefficient and the Young's modulus of concrete are evaluated in terms of the effective age. Finally, the numerical results indicate that tensile stresses concentrate in concrete around steel bars and compressive stresses result in the main bars, and they may affect damage development of the RC column.

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 The 2011 off the Pacific coast of Tohoku Earthquake triggered devastating tsunami which caused various structural damages to RC buildings. Impact tests were conducted using a lateral impact loading system to evaluate the performance of RC wall specimens. The damage of twenty RC wall specimens was classified into penetration, scabbing, and perforation. In order to evaluate the limit impact velocity for scabbing and perforation, the modified Hughes formula was proposed by assuming that tensile concrete strength is a constant value (1.76 N/mm²) regardless of the splitting tensile strength of accompanying cylindrical specimens. The proposed formula perfectly classified the local damage of twenty specimens in this study.

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 Structural characteristics of standard steel office buildings are investigated. Buildings are designed in two types of lateral resisting systems, which are space frame system (SFS) and perimeter frame system (PFS). Moment resisting connections are used in most of beam-column connections in SFS, where the columns are typically square hollow structural sections subject to bi-axial bending moment under lateral forces. Contrarily, the moment resisting connections are limitedly used in the perimeter frames in PFS, where the columns are I-shaped sections and simple connections are used for beams connecting perpendicular to the lateral frames. Steel quantity is minimized under allowable stress design constraints. The design variables are the section sizes. It is found that the total steel quantity and welding length of PFS are smaller than those of SFS in four, seven and ten-story standard office buildings.

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 Cyclic loading tests were conducted to investigate the seismic retrofit effects for steel beams with floor slab. Strain concentration in the lower flanges due to the presence of concrete slab was significantly reduced by attaching haunches to either upper and lower or lower beam flanges in comparison with un-retrofitted specimen, and plastic deformation capacity was improved. However, when the haunch was applied to only lower beam flanges, strains in the upper flanges tended to increase subjected to negative bending. FE analyses were conducted to verify the effect of retrofit, when attaching haunch to only lower beam flange. Numerical results indicate possibility of avoidance of extensive damage to the upper flanges by enhancing force transfer efficiency of lower haunch.

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 Cyclic out-of-plane bending behaviors of cylindrical wall at non-diaphragm connection of CHS-column to H-beam were investigated in experimental tests, in that very large amplitudes far beyond the elastic limit deformation were loaded. All specimens except thinnest CHS's failed in the mode of ductile fracture after gradual penetration of crack into the CHS wall, while they exhibited ample ductility prior to the final fracture. Yield, plastic, and maximum moment capacities as well as elastic rotational stiffness of the connection progressively deteriorated in successive loading cycles, whose decays were represented by hyperbolic curves. The deterioration curves will be utilized in failure analysis of steel frames supported by non-diaphragm CHS columns.

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 In Tohoku earthquake (March 11, 2011), Tsunami flotsams attacked buildings and then caused terrible damage to many of them. For the purpose of preventing the damage, the authors have experimentally studied the loading capacity of concrete filled steel tubular (CFT) members subjected to lateral impacts, so that the CFT members are expected to have effective resistance to the impacts like the collision of flotsams. The purpose of this paper is to derive an evaluation method for the capacity of CFT members against lateral impacts by theoretical manner. The impact response analysis is performed by using a frame analysis program. From the numerical parametric study by using the analytical model, the lateral impact response of CFT member under the constant axial load has been clarified. Being based on the results and theoretical consideration, it is proposed an evaluation method of the allowable input energy by the lateral impact for a CFT member. The method takes both of the energy absorbing capacity of a CFT member and the potential energy release by the axis load into consideration.

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