Dynamic load of the complex and heavy equipment that have high quality functions in located at the specialized buildings destroy covering floor in the present era. To prevent these problems, we focus on the building of collaboration system between floor materials and mechanism of high quality facilities. In this study, we have developed the experimental equipment is reproduced "dragging load", and declared the mechanism of "dragging load". As the result of investigation, we have described the method for prevention of wrinkling problem and the building of collaboration system between floor materials and mechanism of high quality facilities.

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This study examines the equivalent linearization analysis by a sway model which expresses a superstructure on pile foundations considering of the nonlinearity of a soil-pile system, and we propose the seismic evaluation method based on the above analysis. This seismic evaluation method consists of the decision of the failure mode of a superstructure and a pile foundation using the curve of relation of the ductility factor between a superstructure and a pile head, the evaluation of the ductility factor of a superstructure and a pile head by the equivalent linearization analysis, and the decision of the necessity of seismic reinforcement based on the result. In addition to this method, we propose another method consisting of the individual evaluation of the ductility factor without using the sway model. The proposed method is applied to a building which was damaged to pile foundations during the 2011 off the Pacific Coast of Tohoku Earthquake, and the validity of the method is confirmed by this examination.

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This study investigates the vertical responses of seismically isolated buildings by considering the dynamic soil-structure-interaction (SSI) and the vibration of the long-span beam. We first construct a two-dimensional moment-resisting frame model by simultaneously considering the beam vibration and the SSI for a base isolated seven-story building by comparing observation records. As a practical application of vertical response analysis, we tested base-fixed frame models with the equivalently added damping to incorporate the SSI effect. The coupling effects with SSI can be adequately evaluated by adding a damping factor to columns when the frequency ratio to multi-mass model is less than 0.8.

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In this study, the constitutive model which is capable of describing the behavior of metals under the uni-axial cyclic loading is suggested. Many constitutive models for multi-axial stress problems have been proposed. In particular, we have focused on the sub-layer model because it can be satisfied with Masing's rule and be understood easily from the perspective of the mechanics. It is inevitable to incorporate appropriate hardening rules into the constitutive model in order to represent hardening phenomena. In the present work, at first, new hardening rules for the sub-layer model are proposed to overcome shortcomings for the classical sub-layer model where hardening rules are defined for each layer respectively. Then, the concept of the non-hardening region is applied to the sub-layer model with the new hardening rule since the only new hardening rules are not enough to describe the complex hardening phenomena. Finally, the validation of the present model is conducted through comparisons between numerical results and experimental results under the uni-axial stress field.

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This paper presents the fluctuation characteristics of non-linear pile group coefficient. In this study, by evaluating the nonlinear influence coefficients between two piles, we have set up a non-linear pile group coefficient evaluation method which can evaluate non-linearity of soil between and around piles. This method is based on the pile group coefficient expressions which we proposed for the elastic soil in the past. The fluctuation characteristics of non-linear pile group coefficient obtained with this method was confirmed that it corresponds well to that of the analysis results of the three-dimensional finite element method. Based on this knowledge, we elucidated the phenomenon that with pile head displacement increases, the value of the pile group coefficient increases at first, but this value starts to decrease in the later.

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For estimating the bearing capacity of press-in concrete pile which are used for the small building foundations, we collected the loading test data and statistically examined the relations between the ultimate bearing capacity and the conversion N-value by the SWS tests. Correlation was comparatively high in the ultimate point bearing capacity with the average conversion N-value within above and below 1D(D : equivalent diameter) of pile tip in case of sandy soil, within above 1D and below 2D of pile tip in case of cohesive soil. In addition, the press-in force to complete penetration of pile was almost equal to the allowable bearing capacity for the short time loading obtained by the vertical loading test.

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A series of centrifuge shaking table tests with various pile group configurations, as well as a static pushover analysis using an average-stress-dependent nonlinear soil model, were performed to study influence of overturning moment on lateral load distribution within a pile group. The centrifuge shaking table tests show that, as ratio of overturning moment to total pile head shear load increases, lateral load carried by each trailing pile decreases with respect to that of leading pile. The numerical analysis suggests that the moment applied to foundation can produce shear forces at pile head that act oppositely outward with respect to the rotational center. This is probably the main reason why the lateral load carried by the trailing pile tends to decrease as the ratio of overturning moment to total pile head shear load increases.

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The study deals with school gymnasium structures composed of EP roof type lattice shells, gable walls with a high rigidity and with truss arch frames. The collapse mechanisms of the structure are taken to be a horizontal structural collapse such as the member buckling collapse of the lattice shell and a vertical structural collapse such as the tensile member collapse of the gable wall. The purpose of this study is to investigate the static and the dynamic collapse by means of the both elasto-plastic analyses considering a geometric nonlinearity. The estimation method is also proposed to calculate practically the base-shear strength coefficient and the applied seismic lateral and vertical load distributions on the lattice shells, the gable walls and the truss arch frames. The study is practically useful to determine the collapse mechanism and calculate the ultimate lateral strength on the earthquake-proof design for the damage and safety limit earthquakes.

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This paper reports on the development of wood screws that can be used for soft and light wood like Obisugi (a variation of Japanese cedar). The idea of taper screws came from the shape of traditional Japanese nails, and new wood screws in a taper shape were devised. We designed one parallel screw and six taper screws. Test results revealed that the taper shape of wood screws statistically improves withdrawal performance. Both Obisugi and European redwood were tested. The improvement in withdrawal performance as particularly remarkable in Obisugi.

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In this study, shaking table test using 1/3 scale 2-storied wooden frame with 3D-eccentricity was carried out. The purpose of this test is to clarify the influence of the torsional behaviour of a story on that of the other story. Five types of specimen with various arrangements of shear walls in each story were tested. The plan dimension of specimens is 909mm in X direction, 1212mm in Y direction and 910mm in story height. The eccentricity ratio of each story is 0.44 in X direction and 0.0 in Y direction. Torsional behaviour, stress and external force distribution of each story and interaction of multi-story were discussed in elastic and non-elastic range. External force distribution including torsional moment of a story was clearly affected not only by the eccentricity ratio of the story but also by that of the other story. In some cases, an external force was concentrated on the rigid side and torsional moment was generated even in a story without eccentricity. These tendencies are contrary to the theory on torsional vibration of single story, and they are likely to be due to interaction of multi-story. A theoretical solution of interaction of multi-story was applied to the specimens using equivalent linearization technique, and they gave close agreement with experimental results.

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The earthquakes will last for a long time and the effects of long-period components of earthquake ground motions on the response of high-rise reinforced concrete buildings are of concern. Static and dynamic loading tests were conducted on the assumption of long-period earthquake ground motion, using specimens that simulated center and corner columns in the lowest story for comparison. In this paper, the axial load support ability and fracture process of the columns by the difference of loading history were investigated.

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A new reduction factor related to opening height has been adopted for shear wall design in the AIJ standard since 2010. This factor has not been verified experimentally, while it was presented theoretically. Moreover, the other reduction factor legally regulates shear wall design according to the MLIT (Japanese government) regulation. This paper reports laboratory tests to verify agreements between these reduction factors and experimental results. Three 1/6 scale shear wall specimens were tested with different opening configurations. Consequently, it was concluded that the AIJ reduction factor underestimated the strength drops due to openings but the MLIT reduction factor overestimated.

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The objective of this research is to develop a rehabilitation technique which can be easily installed to existing steel frames with minimal-disturbance. An unique approach to design a supplemental load-resisting system using light tension-only rods is adopted. Key structural features of the proposed technique are to reduce tensile stress at critical sections as bottom flange near beam-column connection and to add supplemental stiffness, strength and damping without significantly changing the properties of a original framing. Numerical simulations and experimental tests were conducted to verify the behavior of the developed technique.

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The steel slit shear wall, in which stiffness and strength are controlled by altering the length, interval and pattern of slits, has been studied as an earthquake-resisting element with high energy dissipation capacity. Local buckling in each link (the segment between slits) and strength degradation that would cause reduction of energy dissipation capacity can be restrained by increasing the number of slit rows with keeping the strength and stiffness constant. This paper proposes the use of low yield point steel (LY100) for the steel slit shear wall. Expansion of plasticity caused by the significant strain hardening of LY100 makes shear deformation distribution more equal in each slit row and disperses the strain concentrated in the edge of links. Furthermore, the larger maximum rupture strain of LY100 than that of conventional steel reduces the risk of fracture at the edge of link. The advantages of the proposed steel slit shear wall are demonstrated by both the test and analysis.

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We present the shear joint using half-moon-shaped bearing bolt as an effective fastener between high-strength steel members. Experimental studies were carried out to clarify the maximum strength of the bolted joint and the elastic stiffness of beam flange joint. Also, materially and geometrically non-linear finite element analyses were carried out to show the mechanical properties of the joint with half-moon shaped bearing bolts. This paper shows the concept and capabilities of presented bolts. Obtained result was summarized as follows. The shank of the half-moon-shaped bolt has enough ultimate strength: 0.9 times the shear strength of effective sectional area. Slip back phenomena, in which the diagonal cut face of the shank slips out of its normal position, doesn't occur during large shear forces on the bolts. The half moon bolts always penetrate the connected steel plate so as to fill up a hole. Hence, the present shear joint maintains constant stiffness during a large number of pulsating cyclic loadings.

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