This study focuses on the absorption process of concrete to determine the influence of aggregates on the local water behavior in concrete, by using neutron radiography. At first, water quantification method by using thermal neutron radiography is summarized which is developed in previous researches. With this method, the water absorption process was examined in concrete specimens containing artificial cylindrical aggregates. Using the obtained hydraulic diffusivity, an unsteady water diffusion analysis captured the experimentally observed water distribution around the aggregates. The result shows that the water behavior can be well explained by the geometric layout of the aggregates.

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The development of energy-efficient roofing systems has been of intense interest in numerous countries in recent years, as a measure for reducing the energy consumption of air conditioning during hot weather. In this study, fifteen kinds of membrane waterproofing materials with high solar reflectance were exposed respectively to varying atmospheric environments at six locations within Japan in order to investigate the range of reflectance reduction. In addition, the relationship between the retention rate of reflectance after exposure and the mass of the ingredients and their composition adhered to the surface of waterproofing materials exposed.

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Floor-slipperiness is a crucial factor in designing buildings for cohabitation with pets. This study proposes an indicator of floor slipperiness applicable to small-breed indoor dogs prone to skidding accidents. The incidence of skidding was recorded by applying load elicited by movements of 12 dogs on 6 flooring materials with different Coefficient of Slip Resistance (CSR). The relationship between recorded incidence and floor materials' CSR revealed that dogs slowed their movements to avoid skidding on low CSR floors. A range of CSR that does not slow dogs' movements was determined and its minimum value is proposed as the required lower limit.

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Establishment of a standard of seismic input ground motion, which prescribes its strength and characteristics, is recently an important issue in earthquake-resistant design of long-period structures. This report quantitatively evaluates the soil amplification characteristics which is one of the most important factors when determining seismic input ground motion. Most of the published reports on soil amplification are based on the evaluation of soil amplification characteristics. Soil amplification functions specifying design criteria are found only in the Notice of the Building Standard Law of Japan and a study by Akiyama. In previous report, therefore, the deep soil amplification function to estimate the energy spectrum for structural design was evaluated by multi-reflection theory according to the method proposed by Akiyama. In this report, soil amplification function for whole ground taking shallow soil layers in consideration is proposed. Shear-wave velocity structure of the ground is evaluated using trapezoidal models of both deep and shallow soil. For establishment of the soil amplification function, local features and unevenness of the soil characteristics are considered. Unevenness is evaluated by connecting soil amplification functions with a line segment to envelop them properly.

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After a large earthquake, aftershocks occur subsequently in a wide region, as were seen in the 2011 Tohoku earthquake. Those aftershocks cause secondary damage or delay of restoration activity. In addition, it is reported that there were the region where intensity of shaking due to aftershocks were bigger than that due to a main shock in some past earthquakes. Therefore, it is necessary to take account of the seismic risk due to aftershocks, too. In this study, using aftershocks data obtained in the events of the 2011 Tohoku earthquake and of other historical large earthquakes, the spatial and temporal distribution of aftershock occurrence is investigated and modeled based on the Gutenberg-Richter law and the Modified Omori's law. Then, a probabilistic aftershock occurrence model to predict the aftershocks of future large earthquakes is proposed, which is expected to be useful for development of restoration activity plan after future large earthquakes.

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At a structure damaged, damage locations will be concentrated on structural weak points or points on severe loading condition. They will not be distributed homogeneously. So, local parameter estimation is important for structural health monitoring. In order to estimate local parameter simply, we have studied wave travel time in one-dimensional multi mass system. This paper presents a theory of wave propagation and a possibility for local parameter estimation by detecting wave travel time of one-dimensional multi mass system.

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The P-δ effect produced by the product of structural own weight and the horizontal drift makes a serious effect on structures under earthquakes and impairs considerably their resistance against earthquakes by reducing their energy absorption capacity.
On the other hand, it is possible to establish a design approach in which the P-δ effect is properly evaluated.
In this paper, the proposed design approach is applied to shear type structures and these structures are proved to be able to escape the collapse due to the P-δ effect through the direct application of the time-history response analysis.

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A new stiffness identification method for a high-rise building is proposed when the building includes an unknown vibration source at the top. By performing limit manipulation, the ratios between shear stiffness coefficients of consecutive stories can be obtained from the floor acceleration data and the ratios of the rotational stiffness to the shear stiffness (SR stiffness ratio). The level of stiffness coefficients can be determined to satisfy the recorded lowest natural frequency and the SR stiffness ratios can be obtained to satisfy the compatibility of higher-order natural frequencies. The validity of the proposed method is examined through actual recorded data.

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For the extremely large or the long period ground motions, it is feared that the base isolation layer collides with the side wall due to the extremely large displacement. In case dampers with large capacity are incorporated with the base isolation layer, the effect of the base isolation decreases due to the large reaction force of dampers in small seismic events. To realize the control of the displacement and the acceleration which is the important factor of the base isolation effect, the friction damper with coupling mechanism is proposed. Analytical studies are conducted using the base isolated detached houses with slide bearings and the proposed dampers. To decide a series of damper parameters, the optimum design method is used. Results indicate that the friction damper with coupling mechanism can control the maximum displacement and the maximum acceleration within the design criteria which is decided individually for the input ground motion level.

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The purpose of this study is to propose calculation formulas of bending moments for proportioning of section in an arbitrary shape of slabs, and we treat a fixed end triangular slab and a tangential quadrilateral slab subjected to uniform load in this paper. In our previous paper, we proposed the calculation formula of the maximum bending moments of the triangular slab and the tangential quadrilateral slab. So, we found out the relations between the value of maximum bending moment and the value for proportioning of section at RC standard formula, and we applied these relations to the described shapes of slabs. Here, these relations are following two aspects.
1. RC standard formula gives an average value of the bending moment of a certain width.
2. RC standard formula gives the value that has a certain safety margin against its collapses.

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In this paper, the swarm intelligence (SI) is applied to the structural morphogenesis for free surface shell structure. The design of the free surface shell structure is executed along a lot of design intentions relating ensure of concepts for design and structural performance etc. Therefore, the structural morphogenesis is often treated as the multi-objective optimization problem. In SI, we adopt the particle swarm optimization (PSO) and the artificial bee colony (ABC), and have proposed PSO and ABC implementing a manipulation for decent solution search. The numerical examples for the single-objective optimization problem for free surface shell structure using these procedures have already been shown. The decent solutions have comparatively high evaluation solutions containing the Pareto optimal solution and local Pareto optimal solutions. Our schemes are applied to the multi-objective optimization problem for free surface shell structure. The objective functions are the total and the bending strain energy, and the weight of total member. The numerical examples for symmetric and asymmetric surface shell model are shown. From numerical results, the difference of decent solutions obtained from our schemes is explained by its algorithm. In addition, it is shown that the manipulation technique for decent solution search can maintain diversity not only on the design variable space but also on the objective function space.

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Liquid-filled tanks on a shaking table showed vibratory responses that contradicted the prediction of elementary vibration theory.
The author has been studying the responses that might be caused by the dynamic geometric nonlinear behavior of the system and showed the Lagrangian function that governs the interactive behavior between a potential fluid and elastic container in large deformations. Arbitrary Lagrangian-Eulerian Elements (ALE) were applied to the functional of the two-dimensional model, proposed a new procedure to analyze the problem, and obtained various nonlinear vibration responses corresponding to the vibratory responses in experiments using a shaking table.

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This paper discusses a method to evaluate a seismic response of typical wooden houses with a passive vibration control system by means of a non-linear time history analysis and an equivalent linearization method, with a purpose to establish a structural design methodology for wooden houses. In the time history analysis, a hysteresis model which represents characteristics of a passive control system is proposed, and the applicability is validated by comparing analysis results with experimental values obtained by pseudo dynamic tests and shaking table tests. The proposed model is expressed by combining a fractional derivative model and two types of Bonc-Wen model, that is capable of evaluating properly the effects of the viscous damper which is affected by temperature changes, and a stopper to constrain the displacement of the damper. In the numerical evaluation with use of an equivalent linearization method, additional stiffness and damping ratio of the passive control system are determined based on numerically evaluated results corresponding to the resonant frequency of the main frame. The accuracy of the adopted values is validated by comparing the predicted results based on equivalent linearization method with time history analyses, and it is confirmed that these analysis results may be predicted within error of about 5 %.

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In this paper, moment resisting behavior of split wedge joint is examined. Bending tests for split wedge joint are conducted. Seventy-two specimens are tested, and their parameters are dimension of post, beam, tenon, notch line and wedge and tree species of members. Evaluation rule for moment resisting performance of split wedge joint is proposed using study the authors have done. It is based on the result of embedment test of wooden materials. In addition, Evaluation equation to evaluate more easily is also proposed.

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Prefabricated mud-shear wall is a mud-shear wall in a compact modular size manufactured in factory work. At construction sites it is constructed simply by being fitted into a wooden frame. It keeps the quality stable even if there is no skilled craftsmen, and it significantly shortens the construction period. In this paper we evaluated structural performance of prefabricated mud-shear wall conducted using static loading test and dynamic shaking table test. It is confirmed that the shear wall has a simple structural mechanism that depends on the single unit, and so its structural performance can be analyzed by a simple model. It is also confirmed that ultrasonic measurement method applied to the prefabricated mud-shear wall is effective for damage evaluation estimation.

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Six RC beams were tested with second-layer bars cut off. Test variables were yield strength, cutoff length, number of bars, and length of specimens. The loading was anti-symmetric and cyclic. One of the specimens failed in bond splitting but the other specimens did not, although the observed bond stresses were much larger than the strengths specified by AIJ code. The following conclusions were obtained.
(1) Bond strength of cutoff bars in the second layer needs not be multiplied 0.6 as specified by AIJ code.
(2) To prevent bond failure after plastic cyclic deformation, bond stress of the remaining bars should be evaluated according to AIJ code.

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Lateral-torsional buckling is one of key factors that determine ductile behavior of steel moment frames. Current lateral bracing requirements for beams are established on the basis of monotonic loading conditions in Japanese seismic provisions. However, the relationship between the current provisions and lateral bracing stiffness requirements under cyclic loading conditions has not been confirmed systematically yet. In this study, an experimental study was conducted to assess the effect of lateral bracing stiffness on the H-section beam strength under cyclic loading. Three different lateral bracing types were examined under cyclic antisymmetrical moment. A numerical analysis is used to simulate the experimental results and compute the effects of lateral bracing stiffness, bracing span, stiffener and dead load condition on the H-section beam elasto-plastic lateral-torsional buckling behavior. The results are compared to the requirements of the current provisions and discussed.

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Tapered H-shaped beams have been designed in steel frame structures for reason of advantage of a more efficient utilization of structural materials. On the other hand, the section stiffness of tapered H-shaped beam, such as St. Venant's torsion constant and the warping constant，are decreased along the beam's axis. For that reason, it is more important to investigate the elastic lateral buckling behavior of tapered H-shaped beam than that of uniform H-shaped beam. Considering the above, H-shaped beam with web depth tapered is the subject of this research, and the energy method is used for lateral buckling analysis. Boundary conditions and end moment ratio are included in analytical parameters.

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Seismic retrofit of damaged steel school gymnasium with angle braces is often carried out by replacing damaged braces by larger section angle braces with ultimate strength designed connections. However, the effects of the replaced braces for the retrofit against expected seismic input are not confirmed yet. In this paper, a gymnasium damaged by Tohoku Earthquake 2011 was analyzed including the fracture conditions derived from cyclic tests of angle braces. Furthermore, retrofit options using angle braces with ultimate strength designed connections, strength based designed braces, and energy dissipating braces are analyzed using the same model, and their performances are compared including effects on the acceleration response along the roof.

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The objective of this study is to clarify the relations between the effective length factor and bracing stiffness of continuously braced compression members subjected to linear varying axial force. The buckling equations are derived by using the Rayleigh-Ritz method, and the effective lengths of columns are calculated, taking the bracing stiffness ratio and axial load ratio β as analytical parameters. After showing the relations between the effective length and bracing stiffness, the restraining effects of steel web or slab are discussed. Moreover, the differences between continuous bracing and discrete bracing systems for columns are presented.

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Fishbone-shaped frame is approximate model for seismic analysis of multibay multistory planar frame. However, the previous formulation of modeling is unable to consider strength deterioration in a large plastic deformation range. This paper proposes the method of modeling of multibay multistory planar frame considering strength deterioration for the purpose of investigating complete collapsing behavior. Seismic response analyses of 4- and 8-story steel moment frames are conducted. The numerical analyses show that the modeled frame can predict the state of plastic hinge and seismic energy absorbed by complete collapse.

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To limit damage to buildings during a severe earthquake and to reduce the amount of harm to society, it is desirable that a design method be developed with a view toward reparability after an earthquake. In this paper, acceptable limits of seismic economic loss for buildings were formulated from the viewpoint of profitability. The limit is considered to be used as a design target for the design method. If repair costs exceed the limit, the building will lose profitability and fail economically. The acceptable limits of 1193 J-REIT buildings were calculated and the influence of their total floor area and economic situation was analyzed. Contrary to the expectation, the analysis revealed that the acceptable limit of the buildings with large total floor area and better economic situation tends to be smaller, which means buildings having significant role in economic activity tend to be vulnerable to seismic economic losses.

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