In a current pulverized coal thermal power generation system, CO₂ emission is larger than that of other fossil fuels, so the improvement of power generation efficiency becomes a most important issue. Integrated coal Gasification Combined Cycle (IGCC) has received a lot of attention in recent years. IGCC is basically different from conventional pulverized coal thermal power generation system, electricity is generated by combined cycle, it is said that IGCC is much more efficient than a normal coal-fired power plant. In this method, the coal after gasification is collected as not coal ash but slag. The slag has a tremendous amount of potential of effective use in a concrete field because of no hazardous components eluting and simplification of handling compared with coal ash.
In this paper, using the IGCC slag, a series of mortar and concrete experiment is executed especially focusing on the influence of the amount of fine powder of slag and the mechanical characteristic of slag concrete. Based on the experiment results, it can be concluded that the IGCC slag has a quality to be applied to structural concrete.

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This paper describes aerodynamic characteristics of a 3-D square prism having low structural density. The New Hybrid Aerodynamic vibration Technique is applied to conduct the aerodynamic vibration experiment. In this experiment, the wind force coefficient can be estimated even under unstable aerodynamic vibration and it can be confirmed that the on-set wind velocity get lower in the case of low structural density even though the mass-damping parameters are similar. In order to analyse the phenomena and re-estimate the aerodynamic vibration parameters, the added-mass coefficient based on added-mass effect is introduced. The re-estimated parameters get good agreement with the result of experiment. Some tendencies can be obtained from the result of re-estimated parameters. The on-set wind velocities are estimated based on the ratio of added-density and the response curves. The results get good agreement with the experimental results.

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Laminated rubber bearings are subjected to large end rotation when the bearings are directly attached on the piles and the foundation beams are low in stiffness or are omitted. Because there have been few studies on the effect of end rotations on the mechanical characteristics of bearings, many problems remain unclear. This paper describes loading tests and a mechanical model for simulating large deformation behaviors on the laminated rubber bearings subjected to end rotation. The results of tests indicate that the equivalent stiffness of bearing is decreased by varying end rotation in proportion to horizontal deformation and that the ultimate deformation defined by occurrence of negative stiffness is not dependent on end rotation. From simulation analyses of the tests, it is found that the proposal model well expresses large deformation behaviors on the laminated rubber bearings subjected to end rotation.

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The earthquake response characteristics of the isolators in a base-isolated high-rise building with a set-back were examined numerically. A three-dimensional framework vibration model was subject to seismic response analysis using a software application that takes into account the bending stiffness of seismic shear walls and floor slabs. The tension and compression in the isolators was analyzed for three motion components, the two horizontal components as well as the vertical motion component, input simultaneously for each of 51 strong ground motion accelerograms recorded during actual earthquakes. The results showed that (1) axial stresses in isolators at the corners below the low-rise part are higher than those in isolators under the high-rise part, with more than a few of the strong motions inducing maximum tensile stresses exceeding σ_t = 1N/mm² at these points, which is the conventional seismic performance design target in the design process, and also compressive stresses that exceed the critical stress; (2) the tension in these corner isolators under the low-rise section is affected more by the vertical component of strong motion than by the horizontal components; and (3) the effective maximum acceleration amplitudes of short-period vertical strong motion and of long-period horizontal strong motion can be adopted as suitable indexes for evaluating the strong-motion induced tension in these corner isolators of a base-isolated high-rise building with set-back.

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Empirical relations between short-period source spectra and seismic moment for dip-slip and strike-slip crustal earthquakes in Japan, ranging moment magnitude from 5.7 to 6.9, are developed by spectral inversion method using near-fault strong motion records. The short-period source spectrum A for dip-slip earthquakes is 1.45 times of A by Dan et al.'s empirical relation for crustal earthquakes in the world. The A for strike-slip earthquakes is 0.64 times of A by Dan et al.'s relation. The A calculated from previous source models estimated by empirical Green's function method has the similar trend. The combined asperity area of the previous source models has no differences between dip-slip and strike-slip crustal earthquakes and is 0.8 times of Somerville et al.'s relation for crustal earthquakes in the world. On the other hand, the A for interplate earthquakes in eastern Japan, ranging moment magnitude from 6.6 to 8.2, estimated by spectral inversion method in previous studies is found to be 1.63 times of A by Dan et al.'s relation.

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To make sure the relationship between strong ground motions and building damages, dynamic earthquake response analyses of a building, which had a slight damage during the 2007 Niigata-ken Chuetsu-oki earthquake, are performed. Earthquake records at ground surface have been observed by the K-NET system near the building. Also the building responses were observed during after-shock. The analysis model of the building is estimated based on results of a push-over analysis. Sway and rocking impedances are also installed in this model. The predominant frequency of the building in elastic condition is corresponding to that in after-shock observation. It is demonstrated that the response of the building, which is calculated considering the nonlinear characteristics of soil and building during the main-shock, is larger than the estimated response based on the damage situation of the building.

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This paper presents some excellent numerical results of collapse analysis on an RC-steel hybrid frame used in a school gymnasium. The analyses are done by the fibered plastic hinge method. The limit bending moment and the limit shear force of the column base of the upper steel frame and the limit overturning moment of the RC base are checked in the analysis according to a currently recommended evaluation method. The bending strength of the footing is also checked. The influences of eccentricity between the chord members and the lattice members are taken into account. The numerical result is an upper bound solution, and at the same time, a lower bound solution for the idealized numerical model. The results are compared with those obtained by the conventional α-method.

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The authors examine how partial embedment of a helical screw pile into a bearing layer affects on its penetrability and load-settlement behavior. Both large-scale model tests and field tests had been conducted taking embedment length into account. For model tests, two layered sand deposits with different relative densities were prepared in a calibration chamber.
The test results show the following regardless of the test scale; a torque profile and a penetration rate start change just before reaching a pile toe into a bearing layer. Embedment length equal to a screw diameter, which is commonly required in practice, yields effective mobilize of the end-bearing resistance beneath the helical screw, while less resistance tends to mobilize beneath the pile shaft as embedment length increases. As far as the bearing capacity of a pile is concerned, however, no significant influence can be observed in terms of embedment length into a bearing layer.

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Nonlinear soil-structure interaction effects under strong ground motions should be considered in the seismic design. This paper presents the influence of the nonlinearity between the piles and the soil on the lateral resistance of the pile group and the estimation method of lateral soil spring at the pile cap of the pile group. The major findings obtained from studied are summarized as follows; 1) outside the small displacement range, accompanying the increase of the displacement at pile cap is small increase in the ratio of the pile cap load of the pile group to that of the single pile, as P_G(u₀)/P_S(u₀), 2) P_G(u₀)/P_S(u₀) considering the nonlinearity between the pile and the soil is greater than P_G(u₀)/P_S(u₀) not considering, and the increase of P_G(u₀)/P_S(u₀) are caused by the progress of the nonlinearity between the pile and the soil, 3) if the nonlinearity between the pile and the soil are considered on the soil spring at pile cap of single pile, denominator in the definitional equation of pile group efficiency, the pile group efficiency can be approximated to constant value, 4) the lateral soil spring at the pile cap of the pile group can be estimated by the abridged method, which is the coefficient of lateral soil spring of the single pile multiplied by constant value.

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The main objective of this study is to evaluate the seismic performance of wood structure composed of shear walls with high damping rubber. In this paper, shaking table tests of the full-scale two-story wooden structure composed of high damping shear-wall were descried. Four type specimen with different shear walls were prepared to compare the maximum displacement, energy dissipation and so on. As the result of tests, it is confirmed that high damping shear-wall is effective to reduce the degradation of load due to cyclic loading, especially in a large displacement. In addition, we tried to calculate the seismic response of shaking table tests using time-history analysis

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In this study, a new PCa floor system for an unbonded prestressed concrete (PC) frame structure was developed. Deformation of unbonded PC frame structure is expected to concentrate in the joint between beam and column and, as a result, damage such as cracks to beams and columns can be reduced during an earthquake. Floor slab applied to these structures is needed to be provided with not only sufficient in-plane shear transfer capacity but also system to avoid confinement of movement of beam-column joint. For this purpose, a new PCa slab-beam joint system was proposed and loading tests of full scale specimens were carried out. From the experimental results, it was shown that shear stiffness and strength in the new joint system with shear cotter were almost same with those in conventional half PCa floor slab. Moreover, an evaluation method of in-plane shear of floor slab between the frames with different stiffness and shear capacity was examined based on equilibrium of shear force in frames and floor slabs. Static push-over and seismic response analyses of prototype frame structures were carried out to discuss the requirement for in-plane shear capacity of floor slab and design shear for slab-beam joint. Significant difference was not found between the seismic responses of frame structures with rigid floor and those with the new floor slab system, provided that the slab-beam joint was designed accordance with the proposed evaluation method of in-plane shear.

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The previous part of this paper focused on experimental investigations on soft-story RC frames retrofitted by steel braced frames with the help of the proposed hybrid connection. In this paper, associated calculation frameworks are suggested according to the capacitybased evaluations. The lateral strengths of three fundamental mechanisms, which were observed in the conducted experimental investigations, are discussed and formulated. Moreover, the direct shear resistance of the proposed hybrid connection, which is the most important concern, is estimated. Finally, the experimental lateral strengths of the retrofitted frame specimens are compared with the lateral strengths obtained by the suggested calculation frameworks. The comparisons demonstrate acceptable agreements.

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In general, the column moment demands in steel concentrically braced frames are ignored. However, large concentrations of damage are not seen in real frames since columns are continuous and they possess some flexural stiffness and strength. This paper clarifies the effect of continuous columns and the post yielding stiffness of buckling restraint braces on mechanism of damage control for two story braced frame with restraint braces on pushover and dynamic analyses. It is shown that continuous seismic and gravity columns and the post yielding stiffness of braces in a structure significantly decrease the possibility of large drift concentrations.

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This paper proposes a simple model of a load-displacement relation for predicting the local tensile elasto-plastic behavior of a concrete filled square steel tube column to steel beam moment connections using an external stiffener. This model is developed by superposing the loaddeformation relations of a tube flange and web with external stiffener. The tube flange with external stiffener is modeled as a grid beam with a tetra-linear load-deformation relation, while the tube web with external stiffener is modeled as a tension member with a tetra-linear load-deformation relation. This research verifies the analytical model by comparison with experiment results. The analytical results agree approximately with the experimental results up to large deformations.

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Tests on shear corrugated steel plates were carried out to examine effect of section shape, thickness and boundary condition on shear buckling behavior and post buckling behavior. Based on the test result, previous shear buckling strength formulas were reviewed. Furthermore, tension-field action model were proposed through observation of plastic deformation after shear buckling, and design formulas were derived from the strength model. Comparison with the test results showed that the design formulas provided appropriate strength estimation for shear buckling and post buckling behavior.

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The authors investigated building damage conditions in five areas of Galle, Matara, and Hambantota, Sri Lanka affected by the 2004 Indian Ocean Tsunami. This paper presents tsunami vulnerability functions for the buildings, a relationship between building damage and inundation, in the country. In order to develop the functions, 1,535 building damage data in terms of structural types, solid (mainly reinforced concrete) and non-solid (masonry and timber-frame), and inundation height data of 153 points obtained by the field survey and contour models were examined. The developed fragility curves clearly show structural vulnerability differences, and it will be useful for damage estimation to reduce tsunami related damage in the country in the future.

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