Core samples were taken from a structure several decades old, with coating materials for textured finishes, to make an accelerated carbonation test. Referring to the test result, the carbonation suppressive effect of the aged coating materials for textured finishes was evaluated on the basis of the diffusion theory. In addition, the evaluation result was compared with the prediction of carbonation progress determined from the air permeability coefficient measured at the time of the test. This comparison was intended to validate the reliability of the assessment of the carbonation suppressive effect of the coating materials for textured finishes on the aged structure, using the air permeability coefficient. This study demonstrated that the carbonation depth estimated from the air permeability coefficient, with consideration given to the aging of the coating materials for textured finishes, agreed well with the carbonation depth measured in the accelerated carbonation test.

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In-plane volume change of cement siding due to surrounding relative humidity change is discussed in this paper. The adsorption isotherm and strain isotherm under 25 degree Centigrade are experimentally obtained. From these experiments, it was found that relationships between statistical thickness of adsorption and relative humidity are very close among these sidings. And based on this characteristic, simple experimental equation to predict the statistical thickness of adsorption by relative humidity is proposed. Additionally, the value of shrinkage strain divided by water content has strong relation with statistical thickness of adsorption regardless of type of cement sidings. Based on these two points, in-plane shrinkage predictive equation is proposed.

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To maintain the reliability and soundness in weld joints, Ultrasonic angle beam testing has been conducted in the past. Recently the weld quality has been improved, so the high heat input welding method has been widely adopted, the strength of construction has been declined for increasing weld defects. For this reason the conventional ultrasonic angle beam testing has been weak to detect large and hazardous defects in defect height. This paper describes the easy and reasonable detection and evaluation by comparison if probe's frequencies, angle of refraction, and element sizes.

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We present a new empirical model to spatially interpolate amplification factors of 5 % damped acceleration response spectra obtained at strong motion stations at intervals of about 10 to 20 km for periods ranging from 0.5 to 10 s. The predictor variable is Tz3.2 which is the propagation time of S wave from the seismic bedrock to the engineering bedrock calculated by velocity structure just beneath the station extracted from three-dimensional model with a grid spacing of about 1km. The logarithm of the amplification factors in the Kanto basin, the Nobi basin, and the Osaka basin are modeled by bi-linear regression lines using the Tz3.2. We also interpret the bi-linear regression lines by medium response of surface waves.

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A hybrid analytical and finite element method is proposed to solve the nonlinear sloshing problem in a floating-roof type cylindrical liquid storage tank under long-period ground motion. The contained liquid is assumed to be inviscid and incompressible and the flow is assumed to be irrotational, while the floating roof is considered as a Kirchhoff plate undergoing large deflection. The proposed method is based on representation of the liquid motion by the analytical solution to the potential theory that satisfies the rigid wall and bottom conditions. This requires only the discretization of the liquid surface and the floating roof into finite elements, thus leading to a computationally very efficient method compared with full numerical analysis. Numerical examples are presented to investigate the nonlinear sloshing in oil storage tanks with single-deck type floating roofs damaged during the 2003 Tokachioki earthquake.

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An advanced reduced model is proposed for elastic earthquake response analysis of shear building structures with setback. The proposed reduction method consists of two parts. The first stage is the construction of a reduced structural model with the degrees of freedom at representative floor levels only. The reduced model is constructed using an inverse eigenmode-problem formulation so as to have the same fundamental natural frequency and lowest-mode component ratios at the representative floor levels as the original model. The second stage is the transformation of earthquake input forces into a set of reduced input forces. This transformation is introduced to enhance the accuracy level of the reduced model.

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The present paper discusses on ultimate strength of a shallow reinforced concrete domes supported at four corners. The loads for investigation are not only dead load but also approximate earthquake loads considering anti-symmetrical vertical loads caused by horizontal earthquake motions. The method is based on an elastic-plastic geometrically nonlinear analysis considering both effects of initial geometric imperfections and tensile strength of concrete. Based on the results, several important structural features are revealed. The geometric imperfection distribution similar to those caused by dead load reduces the ultimate strength, and the strength is much reduced if no tensile strength is assumed for concrete. If 40% of the shell thickness and no tensile strength are assumed respectively for the imperfections and for concrete, the ultimate strength is reduced by almost half from the perfect case. The ultimate strength interaction between dead load and earthquake loads shows the importance in design to include the anti-symmetrical load components of earthquake loads. The importance of not only stiffeners at free edges but also shell geometries of bending moment free are suggested.

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In this study, we tested for identifying dimensional effects of rotational stiffness of wedged and halved scarfed joint. At first, a model of stress distribution in bending was made from observation of joints fracture under four-point bending tests. Proposal of rotational stiffness design formula(M-Θ) was derived from this model. Under the tests, M-Θ equation values well corresponded to all types of experimental ones. In particular, rotational stiffness rose in proportion to the cube of the materials height and the cogging width and had asymptotic limit value. These tendencies corresponded to the experiment results.

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Compression tests of Japanese cedar in its L, R, and 45-degree directions under various stress rates were done in order to investigate the viscoelastic effect on the stress-strain curves with a focus on the proportional limit. The tangent modulus decreased gradually with the elevation of stress either for any direction of loading to the grain and for any stress rate of slow to fast loading. This suggests that the so-called proportional limit does not exist in an exact sense. A three-element model interpreted the viscoelasticity of the tested wood such that the spring constant is free from stress rates as well as stress repetitions like the Hookean body, while the dashpot is sensitive to them unlike the Newtonian linear fluid.

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A four-story RC building is tested by using the E-Defense shake-table facility in order to verify the assessments based on AIJ recommendations as well as in order to examine its performance given by the newer Japanese code. The building consists of moment frames and multi-story walls. Ground motions recorded in the Hyogoken-Nanbu earthquake are used, and the intensity of shaking is gradually increased. Story drift responses of the building reach more than 0.03 rad. Finally, multi-story walls suffer flexural failures at the critical sections of the first story. Beam-column joints suffer shear failures, while beams and columns exhibit flexural yielding.

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High-rise truss towers consist of steel tubular section members have high risks to be damaged by seismic input, because their hysteretic characteristics deteriorate after buckling and easy to fracture after local buckling ; However present design does not include the effect of such member fracture. Authors have established algorism to predict member fracture after buckling for tubular members using macro-model, derived from experimental and analytical studies. In this paper, this algorism is applied for time-history analyses and seismic responses of detailed tower structures are analyzed. The validity of proposed method is firstly compared with actual earthquake damages, followed by researches on the effect of member fracture in various truss towers.

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The purpose of this paper is to propose the hysteretic model of laterally unsupported H-shaped steel beams under cyclic loading at one end. We have figured out the lateral buckling behavior, including large deformation region, of the beams under cyclic loading through experiments. The hysteretic model is determined by the lateral deformation, unloading stiffness and cumulative plastic deformation of the experimental data. The validity of the proposed model is examined by comparison with the experimental data.The applicable range of width-thickness ratio of the model is determined by means of numerical simulation using FEM analysis.

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A number of school gymnasia in Japan exhibited or lead one to foresee insufficient seismic performance, and seismic retrofits on them are still underway throughout the country. However, current assessment practices often require the replacement or addition of roof braces, which are very time and cost consuming. Energy dissipating retrofits are better suited than common strength-based retrofits to help reduce excited vibration of the roof and burden of the roof braces and ceilings, however, optimum design and evaluation methods remain unclear. This paper investigates retrofit design using elasto-plastic or viscous dampers, discussing its effects on response reduction for roof braces and practical response estimation methods, followed by proposing the retrofit method which achieves required seismic performances without replacing the roof braces.

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The mixed structures composed of reinforced concrete (RC) columns and steel (S) beams are effective for long spans. Lots of beam-column joint details have been developed. These joints need particular arrangements to transmit stresses between S-beams and RC-columns. In addition, the concrete casting may be inefficient to construct dense concrete joints. The hybrid beams that consist of RC beam-ends and S beam-center could be practical instead of S beams, because beam-column joints may be constructed in pre-cast concrete members. There are some researches on the hybrid beams. In many cases, those H-shaped steel beams are embedded in reinforced concrete beam ends, and large leverage shear stresses are occurred at the connections.
Authors have proposed new connecting way for the hybrid beams, utilizing the boundary steel plate between RC and S-beam instead of the way embedded steel in RC-beam. This paper reports the stress transforming mechanism of new method and the test results of the proposed hybrid beams.

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The authors proposed a new type of structural-wall system(EDSWs) consist of wall panels, coupling steel girders and edge columns which possesses the large energy dissipating capacity and the function which uniforms drift angle of each story.
Because the shear force that is attributable to higher mode responses concentrates on wall part, it is vital to predict higher mode response for the desirable design of EDSWs or wall-frame system including EDSWs.
The authors proposed the prediction of maximum earthquake response story shear not performing dynamic analysis but only performing static analysis by converting a multi-story building into equivalent single degree of freedom system, which can be applied to the Capacity Spectrum Method.

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The main effort on the buckling-restrained braces (BRBs) has been paid to find the strength and stiffness of the BRB cover. On the other hand, influence due to both friction and clearance between a steel brace and a BRB cover has not been investigated regaradless of important factors to influence the capability of BRB. The objectives of this study are to investigate the influence of friction and clearance between a steel brace and a BRB cover on the buckling-restrained brace behavior by using the finite element method. Obtained results through numerical analysis showed that the clearance make more influence compared to friction. Some obtained analytical results, which are relationship between applied force and deformation of steel braces of BRB covers, are verified through some experiments. The analytical results give good agreement with the results of the experiments. Finally, a simple design expression for BRB covers is proposed through analytical results.

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The authors propose a method to estimate the retention of stretch of polyvinyl chloride resin waterproofing sheet using image analysis techniques. The retention of stretch is regarded as the index of deterioration of a waterproofing sheet. Firstly, we originally developed a microscope for taking digital images of the surface of water proofing sheets that can capture the crack clearly. Then various kinds of existing image attributes are adopted to characterize the crack. These features are used as explanatory variables of multiple linear regressions to estimate the retention of the stretch. Estimation models were created and validated through cross validation tests. Finally, we succeeded in creating the estimation model that exhibits about 0.96 in determination coefficient.

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