The experiments on probability distribution of compressive strength of high strength concrete and normal strength concrete were carried out in this study. Shape of probabiliry distribution of compressive strength class of any kinds of concrete were definied normal distribution, theoretically, in quality control. It is clear that the peak of distribution is higher than mean value of strength in high strength concrete, nevertheless the mean value is equal to the peak of distribution in ordinary strength class of concrete. This means the probable minimum would be lower than the specified minimum , make the strength fall below the design strength in high strength concrete.

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Concrete which is a bittle material becomes ductile by adding fiber. However, the relationship between the fracture behavior of fiber reinforced concrete and the property of fiber is not necessarily gasped. In this paper, the analytical study on fiber reinforced concrete under direct tension is carried out by visco-elasto-plastic suspension element method. The fiber is simulated by elasto-plastic element between nodal points. The effect of number, length, direction, yield stress and stiffness of fiber elements on the fracture behavior of concrete is investigated. As the result, the descending portion of stress-strain curve becomes ductile, and the analytical results can comparatively express the experimental ones. The mechanism of bridge effect by fiber can be explained from the analytical results of internal cracks and strains of specimen surface.

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In order to quantify weatherabily of polymeric building materials, reference materials(RM), polyethylene, polycarbonate and poly(ethylene terephthalate), are exposed every month in Sapporo, Choshi and Miyakojima for 2 years. Carbonyl index or ultraviolet absorbance of reference materials are analyzed by multiple regression analysis and Koike & Tanaka's model, based on solar ultraviolet radiation, ambient temperature and relative humidity. Citing meteorological data provided by Japan Meteorological Agency, carbonyl index or ultraviolet absorbance rate are estimated and are plotted on maps. These values shall be adopted_as a new concept of exposure stage.

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Application of photocatalyst into the building materials and components is rather newly developed technology. One of the advantageous features by applying this photocatalyst would be the capability of self-cleaning or self-desoiling on the surface of materials. This paper introduces the results of the outdoor exposure test and the laboratory tests for the various exterior finishing materials treated with photocatalyst. On the basis of the results obtained from both outdoor exposure (already reported as in AIJ Trans. No.564, 2003) and laboratory analysis, the following conclusion could be made at present; Rather high correlation between the water contact angle of outdoor exposed specimen and the color (value) difference could be recognized, the higher hydrophilic nature shows the more desoiling nature under the water contact angle less than 70 degrees, and water contact angle would be one of the key factor for evaluating self-cleaning effect.

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Lessons learned from the 1995 Hyogoken Nanbu earthquake and the excellent performance of seismically isolated structures during the earthquake have persuaded the application of seismic isolation systems to houses. Because of a light weight of houses sliding and rolling types of isolators have been developed. A purpose of this paper is to verify the behaviors of seismic isolation systems under 3-directional recorded earthquake ground motions. 3-dimensional shaking table tests on full-scale seismic isolation systems with different types of isolators were conducted. In this paper, the effects of earthquake motions with 2-horizontal and vertical components on the response characteristics of the seismic isolation systems are discussed.

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The aim of this research is to clarify relationships between the dynamic response of non-linear structures during earthquakes and discrete wavelet transform, which can represent time-frequency characteristics of input accelerograms. First this paper studies the relationship between wavelet coefficients of input accelerograms and the elastic response of structures. Considering fourier transform of the mother wavelet and dissipated energy through damping, an equation was derived which shows the relationship between elastic energy of a vibrating system at an arbitrary time and wavelet coefficients of the input accelerogram. Response analyses showed that the elastic energy calculated from wavelet coefficients can be used to evaluate the time-history displacement of the system, under the condition that the natural period of the system is close to the predominant period of the input wave.

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Structural control and system identification are integrated to directly utilize the results of system identification of an objective structure for its active control. After the structure is expressed as ARX models and an active mass damper (AMD) is expressed as the motion of equation, a state equation and an output equation for the AMD-structure system are introduced in the discrete-time space. By considering the zero-th terms for input signals in the ARX models, the formulation and the optimal regulator problem can be generally applied to building structures. As the measurements, the feedback control law requires the AMD's velocity and stroke and the structure's acceleration at least. Numerical examples indicate high applicability of the proposed control strategy to MDOF structures. The earthquake response analysis and the poles of the AMD-structure system confirm the control effectiveness.

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This paper deals with the shape optimization of symmetric truss structures from the viewpoint of maximization of linear buckling load. Multiple eigenvalues appear very often in structural optimizations dealing with buckling loads, and they are the causes of the difficulty in solving those kinds of problems. In this paper, the stiffness matrices are diagonalized according to symmetricity of the structures by using the group theory, so that the eigenvalues are classified according to irreducible representations. This classification is useful to understand the characteristics of multiple eigenvalue. It is shown that multiple eigenvalues obtained in the optimization problems are mainly caused from the coincidence between different irreducible representations, and the problems canbe formulated as a ordinary nonlinear programming problem by using the block-diagonalization.

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To elect pile foundation firmly is one way to satisfy its demands, - making up functions and structure of the building without losing their bearing capacity, or getting differential settlement-. But it use to be uneconomic, so reasonable way is groped for. We have been proposed damage controlled pile foundation using slender support piles and squat earthquake resisting piles. This paper presents the results of experiments using scale model of soil-pile foundation-super structure with the aim of understanding dynamic behaviour of building suppourted by damage controlled pile foundaiton. The results indicate using earthquake resisting piles controlls relative distance between foundation and ground surface, bending moment of support piles.

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The seismic CPT tests are conducted at 66 sites where soil liquefaction have or have not occurred during earthquakes. The correlations among the cyclic shear stress ratio, modified shear wave velocity V_<s1>, soil behavior type index I_c and the actual soil performance during earthquakes are examined. The critical V_<s1>-value causing liquefaction for sand is found to increase with I_c if I_c<1.9, while it decreases if I_c>1.9. Based on the above relation, the boundary line separating liquefiable from non-liquefiable conditions is presented in terms of V_<s1> and I_c, which is uniquely expressed regardless of the fines content.

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Shaking table tests were conducted for investigating the relation between the subgrade reaction acting on a pile and the soil response in the non-liquefied and the liquefied soil. The subgrade reaction in the non-liquefied and the liquefied soil is occurred almost simultaneously in proportion to the soil shear stress. Before the occurrence of the liquefaction, the subgrade reaction mainly acts on the piles as the reaction forces, and is correspondent to both the relative displacement of the free ground and the ground among piles. After the occurrence of the liquefaction, the subgrade reaction mainly acts on the piles as the external forces. The subgrade reaction is correspondent to the relative displacement of the ground among piles, and is less-related to that of free ground. Though there is a part of the subgrade reaction in proportion to the relative velocity of the ground among piles, this part is very small.

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Present paper proposes a structural optimization method for truss and frame structures having some uncertain factors in its constitutive materials, configurations or design loads by using fuzzy theory as well as genetic algorithm techniques. Genetic algorithm has been already recognized as a strong and a useful tool for optimization problems with discrete variables and has been applied for topology optimization problems of trusses and frames. On the other hand, uncertainties which exist in structural problems such as those of the design loads, of the structural configurations and of the constitutive materials should be dealt with from the view point of the practical structural design. The probability statistics theory has been considered as the only technique for reliability analysis that can treat the uncertainty in structures. Probability theory can be used, when there is sufficient random data to define the probability density function. However, in actual structure design, such cases can be said to be very rare. Furthermore, although various factors (human error, etc.) must also be taken into consideration in order to consider the safety of structures, they cannot be defined within a framework of the probability theory. In this paper, such factors are included by use of the fuzzy theory and the topology optimization problem of frame structures, which have uncertainties in their materials or configrations, is shown to be rationally solved.

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In this paper, three types of moment resisting joints using drift pins are modeled into the three springs, and the relations between the moment and the rotation angle are calculated. The spring elements relating to the moment transfer consist of the connecting elements with the drift pins and the round bar of the tension side and with not only the same drift pin element but also the compressive strain inclined to the grain of compression side. The characteristics of the springs are evaluated by the experimental results in each element. The results calculated by the spring models are compared to the experimental results shown in reference 1). Furthermore the full-scale static loading experiments of the timber frame structure are carried out. Comparing the results obtained by the experiment to the results calculated by the spring models, the validity of the numerical modeling is confirmed sufficiently.

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The connection in precast concrete structure shares the important role for transfer of shear acting along the interfaces. The shear transfer capacity of connection is affected on shear elements such as joint concrete, connecting reinforcement and shear key. Also, it is greatly subjected to connection width formed between two precast units. However, there exist little the monographers which discussed on effect of the width in a precast concrete structure connection on shear transfer capacity. Herein, the direct shear test was performed for the purpose of investigating the contribution of connection width to shear transfer capacity. On the basis of test results obtained, the shear transfer capacity of connection was evaluated by using a compressive strut model. It was found that the theoretical results might estimate well the test ones.

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Seismic performance of existing RC buildings is evaluated by computing seismic capacity index, Is, using the Standard for Seismic Evaluation of Existing RC buildings, while damage level of RC buildings that undergo earthquakes is assessed by the Standard for Post-Earthquake Inspection and Guidelines for Repair and Strengthening. This research is intended to study Is vs. damage level relations for low-rise RC buildings designed by the old code by conducting dynamic analysis on model buildings with a variety of Is values. The effects of deformability type of columns and number of stories on the relations are studied. Two levels of ground motions, the original level of past earthquake records and design standard level, are considered. In the analysis, column hysteresis is derived from test results. Strength deterioration after shear failure and axial collapse that are commonly associated with hysteretic behavior of old columns, are considered. The method presented in this study enables us to assess the damage level of buildings and the damage conditions of the columns if the deformability type of columns, number of stories, Is value and ground motion are given. In addition, the assessed damage level of buildings is compared with the observed damage level from past earthquakes and the Is value required to prevent collapse of buildings is discussed.

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Experimental studies on reinforced concrete columns laterally prestressed by the shear reinforcements have indicated that the performance in shear behaviors can be improved by the active confinement. To investigate the mechanics of the lateral confinement, the 3D finite element analyses were performed on RC columns with prestressed transverse hoops under axial and shear loadings. The equivalent confining pressure and the degree of damage were used as a measure to evaluate active confinement and shear failure quantitatively. The FE analyses revealed that an increase in the resistance against shear failure as well as shear cracking with increasing prestress in the shear reinforcements could be explained by the triaxial state of stress in the core concrete.

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An evaluation method for the earthquake resistant performance of reinforced concrete columns and beams are developed for the performance based design. This paper describes the evaluation method of shear force- deformation relationships of reinforced concrete members. The main features are, 1) shear stress - strain relationships of R/C members are modeled as inelastic after cracking and flexural yielding, 2) shear stiffness after cracking are calculated based on the truss theory and 3) R/C member is separated into five regions to consider inelasticity of reinforcements and concrete. The shear force - deformation relationships of R/C columns and beams calculated by the proposed method shows good accordance with their experimental ones.

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Authors have devised a seismic response control brace, which is available for structures having longer diagonal braces often appeared in supporting structures of industrial equipments. This brace is composed of an ordinary axial force member as intermediate member and two axial hysteresis dampers provided with buckling restraint tube at its both ends. In this paper, the buckling restraint conditions of the brace with the damper are formulated by developing the beam-column theory considering initial deflection of the brace and a small gap between the damper core and buckling restraint tube. At .the same time, stress analysis is carried out on the connection of the brace to the framing joints considering the deformation of connection members and rotational spring constants of the joints. And, effects of the various design parameters for the buckling restraint conditions are discussed.

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This paper presents the results of shaking table test on earthquake response behavior of 2-story space frames composed of H-shaped steel beam and column with shear yielding of joint panel zone. The main objective of this test is to investigate an influence of shear yielding of joint panel on maximum inter-story drift and energy absorption capacity of the frames. The results of the shaking table test are summarized as follow. 1) Maximum inter-story drift in each story of the specimens becomes smaller, as the thickness of doubler plates becomes greater. 2) Energy absorption capacity of the H-2 specimen yielding both beam and panel becomes largest in the test. 3) Fracture of the RBS connections in the H-4 specimen is not observed at the end of the test.

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There exist in Japan a large number of old R/C buildings requiring reinforcement against the possible destructive effects of seismic activity. Responding to this, the authors of this paper propose an innovative reinforcing method that utilizes steel portal frames: the Portal-Grid Method. Based on the fact that for steel the modulus of elasticity and yield strength are respectively approximately 10 times and 20-25 times that of concrete, it is posited that steel portal frames - smaller in size than the respective R/C sections - are able to provide sufficient rigidity and strength to reinforce relatively weak R/C frames without braces. The steel portal frames - connected to exterior of R/C buildings - are composed of reinforcing H-sections whose rigidity can be adjusted to that required for complementing the respective R/C sections. In the process of their research, the authors have experimentally proved that the Portal-Grid Method suitably improves the strength of R/C frames - that the strength and rigidity of the reinforced frames can be calculated by summing up the strength and rigidity of the steel portal frames together with that of the R/C frames.

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We conducted questionnaire surveys to examine the relation between seismic intensities and damage of various non-structural elements of RC buildings during the 2000 Tottori-ken seibu earthquake and the 2001 Geiyo earthquake. RC buildings near the earthquake observation stations were selected for our surveys. Results of our surveys indicate the following characteristics of damage of non-structural elements of buildings in the areas where the JMA instrumental seismic intensity were less than 6.0. a) Damage was mainly detected in exterior and interior walls, window glasses, ceilings and doors. Air conditioning systems, fire protection systems and elevated equipments were slightly damaged during the earthquakes, b) Many kinds of non-structural elements were damaged in the building at the seismic intensity over 5.0. c) Percentages of buildings damaged at non-structural elements increase with older buildings, d) In many cases, several non-structural elements were simultaneously damaged during the earthquake.

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