In this research, Several different ultra-high-strength concretes with water to binder ratio of 0.15 were developed and experimental results of basic physical data, self-induced stress of concrete with different restraint ratio and existence of crack around rebar due to autogenous shrinkage are reported. The major experimental results are: 1) The cracks around deformed reinforcing bar due to volume change of concrete experimentally confirmed, 2) Drying shrinkage of ultra-high-strength concrete affects restraint stress of concrete even it is believed to be close, 3) it is possible to add chemical pre-stress of the ultra-high strength concrete with belite-rich cement, expansive additive and reducing shrinkage admixture.

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This research reports the study on the relationship between paste film and mortar film thicknesses and the need for centrifugal compaction and segregation to propose mix proportion design methods for stiff-consistency high strength concrete with the aim of suppressing segregation due to centrifugal compaction. The minimum thickness of paste film and mortar film for centrifugal compaction tended to increase with the decrease in the water cementitious material ratio. The relationship between paste film thickness and mortar film thickness that enabled satisfactory centrifugal compaction was found. It was also comfirmed that the segregation of coarse aggregate was mutually related to the paste film thickness and the mortar film thickness. Also, the coarse aggregate segregation condition after centrifugal compaction could be predicted from arbitrary thicknesses of paste film and mortar film.

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The deconstruction in repair works of apartment houses is quite different from deconstruction of whole buildings, as to deconstruction methods, works planning, labor requirements, waste quantities and types, state of storage on site and carrying out of waste, etc. The objectives of this research were to get basic information for improvement of deconstruction in repair works of apartment houses, and to promote collecting and recycling of deconstruction waste. Research team recorded deconstruction of 5 apartment houses and analyzed each worker's labor and quantity and quality of each material to compare deconstruction in repair works with deconstruction of whole buildings.

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This study clarifies that the sense of touch with white cane can recognize the change of unevenness more sensitive htan treads. It is known by the experiment that the degree of recognition of the change of unevenness, hardness and slippeiness are compared by two type of stimulus from the floor, stimulus sent to a hand through white cane and stimulus sent to treads through footwear. This means it is so useful to change the unevenness of floor to inform something to blind people without providing any conscious to ordinary people. However, it is difficult to know the change of slipperiness in sense of touch with white cane so that dangerous case can be caused without giving any notice if they get into the slippery zone.

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In order to conduct structural reliability analysis using the third-moment method, one should firstly compute the first three moments of the performance functions. In the present paper, the moment computation methods for some commonly used simple functions including linear sum of product of independent random variables are summarized. A a general formula for computing moments of any power of a lognormally distributed random variable is presented. For the functions with second, third, and fourth power or reciprocal of an arbitrary distributed random variable, formulas for approximating the first three moments are given. The simplicity and efficiency of computing the first three moments of the performance functions in practical engineering with the aid of the present formulas are examined from several numerical examples.

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This paper describes the characteristics of overturning moments and a method for estimating external forces on a prestressed concrete tower for a propeller-type wind turbine with three blades (Hub height: 50m, Rated power: 600kW). The overturning moments based on field measurements were investigated using strain-gauge data. It was found that the static overturning moment in the along-wind direction was affected by teh thrust of the wind turbine control. Furthermore, the standard deviation of the overturning moment increased in the ranges from 5m/s to 10m/s. This is because the first natural frequency of the wind turbine tower corresponds to the blade-passing frequency, i.e. the 3P frequency. In addition, the fluctuation of external forces acting on the wind turbine tower was estimated by inverse analysis based on the model frequency transfer function, using field measurement data. As a result, the relationship between the fluctuation of external force and the rotor speed was derived and a pitch control method was found.

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This paper presents a performance based design method which is able to estimate the energies of the structures with bilinear typed viscous dampers and bilinear elasto-plastic dampers by means of separated variables; that is, an equivalent energy spectrum for given ground motions is expressed in terms of the product of an elastic spectrum _pS_<v,40>(TE) and empirical formulas of viscous damping ratio h_o, bilinear relief velocity ratio (=maximum response velocity/relief velocity) μ_v, second viscous coefficient ratio P_v, ductility factor μ_d, and bilinear stiffness factor P_d The desigh diagrams are also proposed by making use of the empirical formulas. Thus, design parameters of dampers can be easily evaluated, if a designer specifies the values of h_o,μ_v,p_v,μ_d and p_d for the design spectrum of a ground motion. The paper shows also good agreements between the estimated design values and the results computed by non linear time history analysis.

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In order to investigate seismic response of long period structures such as oil storage tanks in Tokyo bay area during the Tokai earthquage (M8), which will occur at about200 km southwest from Tokyo in the near future, we quantitatively predicted long-period (> 4 sec) ground motions of this area by a neq procedeure using 3D finite difference method. Pesults show that during the Tokai earthquake, the long-duration and long-period ground motions are excited by the deep sedimentary basin and the peak levels of response spectra are different between east side and west side of Tokyo Bay.

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The purpose of this study is to find out a proper algorithm for semi-active seismic response control of base-isolated building. In the study, in order to perform hundreds of shaking table test, a scaled base-isolated three-story steel frame with a miniature capacity adjustable damper is used. In the first part, mechanical properties of the miniature bypass type magneto-rheological fluid damper are studied based on a series of the sinusoidal displacement tests results. The Bingham model was found to be quite effective to simulate the mechanical properties of the MR damper. In the second part, several passive/semi-active control algorithms are studied, among which, both tne response feed-forward control algorithm and the fuzzy control algorithm are found to be better than the other semi-active ones and the passive ones. It is also confirmed that test results compare with prior analytical ones fairly well.

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This paper proposes a constitutive role for the viscoelastic materials combining iso-butylene and stylene polymers. Part 1 provided highly accurate linear rule under wide range of temperature and frequency. Part 2 proposes and extension of the linear rule wich can consider the strain sensitivities. So-called temperature-frequency equivalency principle is found applicable even under the large shear strain, and it is utilized for efficient analytical modeling of three distinct viscoelastic materials. The nonlinearities under the stable condition as well as the non-stable condition are carefully considered to the model. The model shows excellent accuracy over a wide range temperature, frequency, and shear strain of the sinusoidal loading, as well as random loading such as the building response displacement and the gradually increasing and decreasing displacement.

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The P-δ effect produced by the gravity load and the lateral deformation of frames is most important in the high-rise building under earthquakes. A great contribution has been made by previous researches for the clarification of the P-δ effect. However, the real effect of the P-δ effect on the seismic design still remains ambiguous. In this paper, a simple expression of the P-δ effect on the required base shear coefficient is derived for shear-type multi-story frames.

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This paper discusses the wind tunnel tests for a tall building model having either viscous or visco-elastic damper under the turbulent boundary layer flow. The wind tunnel tests are carried out either the across- or along-wind direction for the viscous and the visco-elastic damper systems, respectively. This wind test set-up includes a special measurement system to obtain the damper hysteetic loop, then the response property of damper and system are discussed by the referring to the obtained loop. In case of the severe wind speed, the response of visco-elastic system is smaller than the viscous system because the stiffness of visco-elastic damper contributes to the stiffness of system.

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In this paper, and analytical model of wooden structures with the sheathed shear walls is shown. In this model, the stretching rigidity of the plywood is assumed a rigid body. Therefore, the degree of freedom can be reduced. This analysis method can analyze walls with random nailing arrangement. And, it is possible to handle multiple walls. The advantage of this method is to simple consider the sheathed shear wall for existing frame analysis program. The effectiveness of this analytical method is verified by comparing with the experimental result and we investigate the mechanical characteristics of the sheathed shear walls numerically.

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Static horizontal loading test on a six-piles group foundation was conducted to investigate the ultimate strength and defprmation capacity of steel and concrete composite pile-group foundation. The maximum load was 13,200kN and the maximum horizontal displacement of foundation was 33cm. After the test, the buckling of the steel tube at the pile head was observed. Simulation analyses of the test results and single pile foundation were also conducted using 3 dimentional non-linear finite element method. Based on the test results and analytical results, subgrade reaction for each pile of the six-pile group foundation was studied.

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The purpose of this paper is to obtain useful buckling data on the single layer two-way grid dome with diagonal members. The dome is composed of circular steel tube menber, spherical nodes and PC bar members. PC bar members as tension member are placed diagonals of the two-way grid. The numerical method considers both node size and rigidity of tubular member ends. The numerical analysis parameters of domes are the attachment of tension member, the initial axial force of tension member, the load pattern and so on. For these domes, effects of these parameters on both buckling load and mode are examined. As a result, the buckling load of two-way grid dome increases by the attachment of tension member and the intruduction of the initial axial force to tension member respectively. Initial axial force of maximum buckling load is defined by the initial axial force of tension member that the buckling load of two-way grid dome becomes maximum value.

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Full-scale tests were carried out to examine the seismic performance of three-story timber frame structure with moment resisting joints. Size of this frame is 5,460mm by 5,460mm wide and 8,580mm height, total weight was 163kN. Specification of damage points, i.e. repair point, was controllable with this method which is concentrated damage points to the joint parts. This structural frame was repaired after the shaking table tests, and examined the effect of these repairs. The experimental result showed not only high resistance to earthquake but also effect of repairs. About comparison of experiments and analysis, both Static and Dynamic analysis almost coincided with each experimental results.

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Designing space frame, buckling is the most important phenomenon. The purpose of this study is to estimate the buckling strangth of round thimbers (Japanese cedar and Japanese cypress) and to evaluate the influence of several characters such as knots and average width of annual rings and so forth. By full-size test, two factors: initial deflection and average width of annual rings were found to be the major points. By regulating these two factors, specified design strength of buckling is defined based on the standard strength by Architectural Institute of Japan code.

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The energy based seismic design for R/C structures has been developed by the authors and others. A major method of performance based seismic evaluation for R/C structures is to predict the maximum value of response displacement under earthquakes and compare the damage with the allowable maximum displacement. Up to the present, the method for predicting the maximum response displacement is proposed and the validity has been analytically confirmed and the required data to investigate the damage evaluation and dissipated energy of R/C beams with flexural yielding under earthquakes have been obtained. In this paper, to evaluate the damage of R/C beams with flexural yielding under earthquakes, based on the results of static loading tests, safety limit state is defined by the damage of hinge zone and the cumulative damage is investigated by applying the cummulative damage index which Park and Ang. proposed. After the investigation, the equation to calculate the energy dissipation capacity of R/C beams with flexural yielding subject to earthquakes is proposed.

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Deflections of reinforced concrete slabs increase by reduction of flexural rigidety and steel slippage at the fixed edge caused by cracking, and it increase furthermore with time by bond-creep between bar and concrete. Calculation method for long-term deflections in consideration of such characteristics were suggested, but those methods don't satisfy both accuracy and practicality. In the present study, we suggest the practical calculation method for long-term deflections based on bond-creep characteristic. The validity of this method was confirmed by the comparison with accurate calculation and experimental results, and the availability as a practical calculation method for long-term deflections was shown.

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The authors described buckling strength and post buckling strength of thin steel plate with aspect ratio of 1.0 partially supported by steel frames in the previous paper. In this paper, the buckling stress of the plate of aspect ratio between 1.0 and 3.0 used by the bracing model is discussed. The approximation formula of the buckling strength is proposed by using the tensile-compressive bracing model. The result are compared with the buckling mode analysis and the geometric nonlinear analysis by FEM. The approximation formula of the post buckling strength of thin steel plate combined with steel stiff frame is proposed in consideration of stress distribution and yield condition. Also the relationship between the bending rigidity of the steel frame and post buckling strength of the steel plate is examined.

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In our previous paper, the possibility of flexural bucking of slender piles in liquefied soil was presented, and the buckling stress for the AIJ design code is estimated. Then the boundary conditions were assumed to be pinned support, but in the real structures, the pile heads will move laterally during earthquake. This paper describes the evaluation of the buckling length of slender piles with roller supports on the pile head when the soil liquefies and then the distribution of the coefficient of the subgrade reaction is assumed to be unified or triangular. The relationship between the buckling length of the slender piles and the soil-pile interaction is presented.

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This paper proposes a new simple model for a load-displacement relation for predicting the local tensile elasto-plastic behavior of concrete filled square steel tube (CFT) column to steel beam moment connections using internal diaphragms or internal diaphragms with extended flanges. This model is developed by superposing the load-deformation relations of a tube flange web. The tube flange is modeled as a grid beam with a tetra-linear load-deformation relation, while the tube web is modeled as a tensile member with a tetra-linear load-deformation relation. The strength of the internal diaphragm is superposed to the strength of these tube load-deformation models. The analytical results agree approximately with the experimental results up to large deformations.

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In order to improve the accuracy of risk analysis, authors propose a seismic hazard analysis method using two ground motion intensity measures; peak ground acceleration (PGA) and peak ground velocity (PGV). Since the seismic hazard is expressed by the joint probability of exceedance for given PGA and PGV, it is necessary to evaluate a correlation between these intensity measures. Recently large amounts of earthquake observation data have been utilized by K-NET and KiK-net databases, so that the above correlation can be calculated. In this paper, the correlation in the Kanto district is evaluated, and is applied to seven reference sites, followed by the conclusion that North-Kanto area and South-Kanto area possess different seismic hazard in the aspects of the shape of hazard plane, and the inclusion of dependency of correlation on seismic magnitude or on the focal distance has a large effect on the hazard estimation.

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Building damage detection technique which we had developed, has been successfully applied to past earthquakes such as the 1995 Kobe, the 2001 India, and the 2003 Bam, by using the compound index, z-value, which is the value derived from the correlation and difference in intensities between pre- and post-event SAR images. This technique was applied to the affected areas due to the 2004 Niigata-ken Chuetsu earthquake on October 23, 2004, by using one pair of Radarsat images taken before and after the earthquake. However, it was not possible to identify any significant distribution of damaged buildings. In this study, we examined the reason and proposed a new technique by using two pairs (pre-seismic and co-seismic) of SAR images, to identify smaller building damage ratios in less densely built-up areas compared to previous techniques. The main idea is to minimize the effect of signal noise and tempral changes of the earth's surface, on building damage estimation, by calculating the difference values from the two pre-event images and one post-event image. In a macroscopic point of view, the distributions of the both deference values of z-value and correlation coefficient in built-up areas were in good agreement with damage by survey reports. In Yamakoshi village, located in highland, we also could identify large-scale landslides with accuracy as good as interpretation from aerial photos.

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