This study discusses experimentally the relationship between the major nine parameters used for fractography of concrete and the mechanical properties of the specimens. The authors employed 18 types of specimens made of different mix proportions of concrete with a different maximum size, a different quantity, a different fineness modulus and the brand of aggregates, but the water-to-cement ratio is about the same. They include not only monolithic specimens made of cement paste or mortar, but also jointed specimens with placing joint at the center. The authors obtained mechanical properties and fractographic parameters with testing and analyzing such various types of concrete specimens. The findings are as follows:
1. The nine fractographic parameters are closely related to each other reflecting the extent of crack paths and the depth of fracture process zone, though they have the different viewpoints with focusing on the extreme points (i.e., the height or its derivatives), the increase of the length or the area from the projected ones, or the local curvature.
2. The most consistent fractographic parameter to the mechanical properties is R_S (the ratio of the fractured surface to the projected one) among the parameters analyzed in this study, which is considered to be the results of the extent of crack paths and the depth of fracture process zone. Other 8 parameters are closely related parameters to R_S.

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An effect of not only subsurface structure but also deep ground structure on an amplification factor depended on earthquake magnitude is investigated by using records of KiK-net observation sites where information of ground structure to seismic bedrock is already obtained. Relationship between moment magnitude (M_w) of an earthquake and an amplification factor is examined at each observation site. The relation is not clear at observation sites with low fundamental frequency in transfer function. Since the transfer function at observation sites of thick sedimentary layer is amplified in broadband frequency range regardless of an earthquake magnitude, it is conceivable that the amplification factors at their sites are little dependent on earthquake magnitude.

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A series of bidirectional loading tests were conducted on a high friction type sliding rubber bearing. Tests were conducted under horizontal bidirectional loading and constant or fluctuant vertical loading. Regardless of the vertical loading methods, the maximum shear strain under bidirectional loadings increased approximately 40% - 50% compared to nominal shear strain. Reflecting mechanical characteristics of the bearing, the analytical model of elastic sliding bearings was proposed. This model accurately represented force-displacement relationships under horizontal bidirectional loading and constant or fluctuant vertical loading.

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The derivation of fundamental equations about the free vibration of spiral thick cylindrical shells is presented in this paper. Firstly, the strain-displacement relationships is based on assumptions of the three-dimensional coordinate system. Then, the principle of virtual work for the vibration of spiral thick cylindrical shells is formulated with some numerical results using the Rayleigh-Ritz method by considering rotating inertia and shear deformation. The numerical results are compared with those which are in the literature and are obtained by finite element method, etc. The method presented in this paper is useful for analyzing free vibration of spiral thick cylindrical shells.

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It is important to accurately estimate the effects of the building basemat uplift and structural response for strong earthquake motions in seismic design of nuclear power plant buildings. In this paper, dynamic centrifuge tests were performed using rigid structure on sand and clay deposits embedded in sand to investigate the difference of structure response due to difference in the bearing stratum, and effect of adhesion between basemat and clay deposit. It was shown that (1) the embedment and the adhesion were effective in suppressing uplift; (2) the JEAC equation for ground contact ratio gave a safe side estimation.

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Motion behaviors of the national heritage five story wooden pagoda at Hokekyouji temple are observed from 2007. Continuing part 1,modal and response analyses for the pagoda are conducted. The model is made by using the beam vibration modes. Response analyses are carried out for both 3/11 earthquake and strong wind. As results of linear numerical calculations to strong earthquake motion and strong wind, the damping about 5%-10% would be agreed with observed response data. Modal analysis results showed the possibility of resonance between a pagoda frame and center column. However, in actual pagoda, it would be difficult to expect dynamic damper effects because of irregularities of pagoda structure.

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One of key issues of recent seismic structural design for buildings is the safety performance against long duration earthquake, repeated earthquake and severe earthquake after main shock. It may be difficult for conventional shear walls of wood house such as bracing and plywood shear wall to survive during their earthquake.
In this study, shear wall with high stiffness rubber was proposed to prevent the degradation of seismic performance during repeated earthquakes and shear wall test and shaking table test were conducted in comparison with plywood conventional shear wall.
Following results were obtained:
1 In shear wall test, it was found that no degradation occurred in proposed shear wall in the range of 1/30rad.
2 In shaking table test, the specimen without proposed shear wall was damaged in three times severe earthquakes, while the specimen with it was survived in five times severe earthquakes.

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This paper proposes the equations to predict the seismic response of the buildings whose yield deformation angles depend on the horizontal strength, based on the equivalent linearization method. Then, the paper discussed the difference and characteristic of the seismic performance of the buildings due to the types of the yield deformation angle. Finally, the paper presents the approximate equations of the seismic response in the form of the function of the factors used in the Calculation of Lateral Load Carrying Capacity, and discusses the difference between the Calculation of Response and Limit Strength and the Calculation of Lateral Load Carrying Capacity.

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We developed the new joint element called “disk shear-key” for seismic retrofitting. This joint element is consisted of steel disk and anchor bolt. We had tested to clear the basic structural performance by direct shear test. Retrofitting members are connected to existing frame through indirect-joints generally. In this paper, the joint loading test and the frame loading test are conducted to investigate structural performance of disk shear-key put in indirect-joints. As a result, it is found that the horizontal load-capacity of frame is estimated by adding shear strength of column, punching shear strength and shear strength of disk shear-key constructed by the joint loading test results.

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The sway and rocking generally have a significant influence on the seismic performance of buildings with the pile foundation, particularly in the span direction. The major purpose of this study is to investigate the difference of the force distribution along the height of superstructures due to the vertical displacement of the piles. The paper also discusses the adaptability of the analytical method of the conventional sway and rocking model. It was concluded that the difference of the force distribution due to the vertical displacement of the piles was explained by decrease in the rotational stiffness of the foundation, and the effect of the ground deformation should be considered in the modeling of sway and rocking even for low-rise buildings.

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The objective of this study is to clarify the influence of out-of-plane resistance of a beam web. H-shaped beams are connected to columns which have torsional stiffness such as square steel tubes and the out-of-deformation of the upper flange is restrained by floor slabs. The lower flange is modeled as a fixed end column subjected to varying axial force and restrained by the beam web continuously. The buckling strength and the effective length factor of the column are calculated by using the Rayleigh-Ritz method and analytical parameters are stiffness ratio and axial force ratio. The relation between the stiffness ratio and the effective length factor are presented and it is shown that the influence of the torsional stiffness of a lower beam flange to these relations is small. The ratio of the beam length to width of the flange which can expect the yield strength of the beam flange subjected to compressive force is presented.

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In case of a large earthquake, conventional RC structures absorb seismic energy by main frames. In order to secure property value of a building, buckling-restrained braces are used for RC structures. The buckling-restrained braces that the authors have developed, can simultaneously adjust yield strength and axial stiffness. The authors have also developed the new connection "stud-gusset plate" that can joint of the buckling-restrained braces to RC structures. In this paper, the design method for a damage-controlled RC structure using the buckling-restrained braces and the stud-gusset plate is proposed. Conducting a trial design according to the proposed design method, the validity of the design method is confirmed.

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In order to analyze the redundancy of steel frames in fire, it is important that the load-deformation behaviour of friction type high strength bolted joints at elevated temperature is clarified. In this paper, influences of plate thickness, end distance, fastening of bolts and steel temperature on the deformation behaviour of the bolted joints are discussed on the basis of the elevated temperature tensile test results. In case the plate is thin and the failure mode is tear-out, the ductility of the joints increases. However, if the failure mode is changed from tear-out to bolt in share due to increase of temperature or end distance, the ductility of the joints decreases. Fastening of bolts slightly affect the load-deformation behaviour of the bolted joints at elevated temperature.

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