This research examined the durability performance of high quality concrete in the acid sulfate soil where the pH value was about 4〜5. The outdoor exposure test was carried out in Kirishima Hot Spring zone for more than ten years. The summary of the results is shown below. The ratio of mass decrease of each specimens was 4% or less. The length and dynamic elastic modulus of these specimens hardly changed. Furthermore, the neutralization speed was also very slow. Especially, the concrete having a water-binder ratio of 0.30 showed the outstanding durability performance.

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This study aims at evaluating shrinkage cracking risk in reinforced concrete structures, which has not been established in past studies. To achieve this goal, analytical scheme to calculate the probability of shrinkage cracking was proposed. In this scheme, the variation of shrinkage restrained stress, that of concrete cracking strength, and safety factor are to be determined. The first two were set via simple analytical simulation of structural elements, and the last factor was based on the comparison between cracking record of actual RC member and analysis results. Finally, this scheme was applied to construction process, and its validity was demonstrated via construction results.

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Although construction sealants are used for dynamic joints with thermal or seismically induced movement the general test methods employed in the evaluation of the weatherability of construction joint are based on weathering test without movement. In this study, we evaluate the weatherability of sealants with a new test method using newly developed test specimens, which enable exposing the cured sealants to compression and extension at the same time in a single test specimen. In this evaluation, we confirm that the surface degradation of sealants is accelerated by the additional movement cycles.

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This paper described proposal and business application result of a management system using the computer in order to efficiently operate building automation construction system. The main content is according to the following. 1) It is necessary to control work planning which is detailed every individual and the execution grasp for the operation of the construction system. 2) Computer aiding was indispensable to the management, and the system constitution which could flexibly carry out the each business treatment was realized. 3) Using unique ID of the every member, the simplification of the delivery of plan data and results data was realized. 4) Three-dimensional CAD display of the every member would be able to facilitate the confirmation of plan content and results content.

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ECC (Engineered Cementitious Composites), which is grouped in one of the fiber reinforced cementitious composites, shows pseudostiain hardening behavior with several percent tensile strain and multiple cracks. Evaluation method for tensile properties (tensile strength and ultimate strain) of ECC is proposed by using bending test results. In this research, uniaxial tension test and bending test of PVA-ECC (ECC with Polyvinyl alcohol fiber) is conducted to obtain correlation between tensile properties obtained by both tests. From test results, comparison value for tensile strength and ultimate strain is 0.80 and 0.87, respectively. It is considered that bending test has possibility to be performed as tensile quality control method multiplying a reduction factor of 0.7.

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This study is the first step of the development of the prediction technique for wide-band random response of a structure subjected to fluctuating wind force. The authors have presented a prediction method of fluctuating wind-force induced an elasto-plastic response based on energy balance, and showed its validity. However, the method was limited to the case of a narrow-band random process. Therefore, it is necessary to expand the method to the case of a wide-band random process in order to make the method more practical. This paper presents a prediction model of a probability density function of an elasto-plastic response displacement amplitude of a structure subjected to fluctuating wind-force, and, in turn, investigates the validity of the model.

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In this paper, the four-parameter (4P) Lambda distribution, whose four parameters can be easily determined using the published tables in terms of the mean value, standard deviation, skewness, and kurtosis of the sample data, is investigated. From the investigation of this paper, one can see that this distribution, having characteristics of simplicity, generality, and flexibility, can be applied as a candidate distribution in fitting statistical data of basic random variables and can be used to represent or approximate the most popular one-, two-, and three-parameter distributions. A fourth-moment reliability index based on this distribution is derived and its application to structural reliability assessment is discussed. Numerical examples are presented to demonstrate these advantages.

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A spectral inversion method adopting new functional model of damping factor with its lower limit is proposed for identifying more sophisticated attenuation characteristics of rock sites. The proposed model is applied to borehole array data recorded at hard rock sites. The identified lower limits of damping factor agree well with experimental material damping factors derived from laboratory test of rock samples. Therefore it can be interpreted that the lower limit of proposed model may be corresponding to actual material damping factor. Moreover, we indicate that frequency dependent characteristics of the damping factor at rock sites could be interpreted as a theoretical damping due to scattering of inhomegeneous rock.

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Simple equations for evaluating group factors of pile foundation for two-layered soil have been already proposed by the authors. In this paper, we improve the design equation for horizontal group factor, considering of the ratio of shear wave velocities of two-layered soil. As a result, the accuracy of horizontal group factor in the case of actual condition can be improved. In addition, the horizontal interaction factors for two-layered soil are proposed here. The horizontal group factor in the case of irregular disposition of piles can be precisely evaluated by using these interaction factors.

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In the excavation work on soft ground, the soil improvement method by quicklime piles is likely to be employed in order to obtain the safety of the earth retaining structure. In the design of earth retaining structure, it is important to evaluate precisely the improvement effect on soil property and the prevention effect of earth retaining wall displacement. In this paper, based on soil investigation of improved ground and field measurement of earth retaining structures, the evaluation method of the effect on the soil property and earth retaining wall displacement is presented.

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This study discusses a retrofit method for telecommunication steel towers by using buckling restraint braces (BRB), and proposes a method to determine the optimum arrangement. First, an ordinary tower on a SRC substructure is investigated to see how it behaves under earthquake motions. Second, a tower installed with BRBs, a retrofit model, is also analyzed. Based on both analyses, it is concluded that introduction of such braces can improve much the earthquake resistant capacity. And finally, determination method of optimum arrangement by the genetic algorithm is proposed using a grid computing system. The performance of the hybrid algorithms and efficiency for solving the optimum arrangement problems is illustrated by the results of numerical studies.

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Single shear loading tests of nailed joints were carried out in 6 types of inorganic and wooden sheathed walls with various loading velocities in the range of 0.1-30cm/sec. The followings are the results. In the case of monotonic loading tests, the load increased as the loading velocity increased in all the types. The load ratio was between 1.1 and 1.4. As the loading velocity increased, the maximum load increased with the inorganic elements, and it little changed with the wooden elements. The results of the monotonic loading test were analyzed about the effect of loading velocity. When the loading velocity was in the range of 0.1-3 or 5cm/sec., the load ratio became 1.1-1.25 in proportion to increasing the loading velocity. When the loading velocity exceeded 3 or 5cm/sec, the inclination of the load ratio depended on the displacement. In the small displacement, the load ratio decreased rapidly. As the displacement became larger, the decreasing rate of the load ratio became smaller When the displacement was more than 5mm, the load ratio kept increasing gradually up to 1.2-1.4 at 20cm/sec, and then decreased, in the case of plywood, however, the effect of the loading velocity was little. In the case of cyclic loading tests, the effects of the loading velocity was confirmed.

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This paper presents the fundamental earthquake response characteristics of 2D wooden-framed house, Nagaya, models with uni-axial eccentricity. Differences of earthquake responses between single and quadric Nagata models are shown. The effect of wall quantity variation of the orthogonal direction on the vibration control is examined. It is found from the analytical results that the displacement and the acceleration responses of the single model are larger than that of quadric one, therefore pulling down of Nagaya consisted of several houses leads to the bad amenity during earthquake. When the wall quantity of the models has one and half times as much as the other eccentric direction one, torsional vibration would be rarely caused.

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It have been already reported that the joint eccentricity between deep wall beam and column would reduce significantly the shear capacity of column, by previous other's papers verifying reinforced concrete building damages in the 1968 Tokachiohki Earthquake, the 1994 Hyogo-Ken-Nanbu Earthquake and the 1997 Kagoshima-Ken-Hokusebu Earthquake in Japan. Current understanding of the shear behavior of the columns is still inconclusive and more research is still needed. This paper presents an experimental investigation on the shear behavior of columns eccentrically jointed with deep wall beams including spandrel walls and hunging walls, subjected to cyclic loading. This experimental portion of this study tested seven rectangular reinforced concrete columns jointed deep wall beams. Other research data found in the literatures were used to supplement the experimental data. Based on test results, the stiffness and the shear strength of columns are clarified to be reduced to them of columns of which the column heigth is equal to the opening height from lower wall beam top to upper beam bottom; the minimum of reduction ratio in the shear strength is approximately 60% to 63%. The main reasons of the reduction are two; the torsional moment due to the joint eccentricity, and the stress concentration in column derived from the restraint by wall beam. For case that the influence of joint eccentricity is significant, a formula to predict the reduction ratio is suggested herein.

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The AIJ "Design Guideline for Earthquake Resistant Reinforced Concrete Buildings Based on Inelastic Displacement Concept" requires that the shear carried by arch action shall be ignored in the reinforced concrete beams with openings. The validity of this requirement, however, has not been verified yet. In this paper, 12 reinforced concrete short beams with web openings were loaded monotonically, in order to investigate the arch mechanism in the solid portions. The test variables were the size and location of the openings, bond performance of longitudinal reinforcement (i.e. bond or no bond) and the shear span. The conclusions obtained from this investigation were as follows. 1) The shear carried by arch action existed in the test beams having axial reinforcement with no bond. 2) The ultimate strength of the test beams was given by the smaller between the ultimate strength in the solid portion and the one in the openings.

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The structural design of a reinforced concrete building aims at performance based design. With upgrading of required performance, the demand for the building changes to be used with small repair cost even after a severe earthquake. RC members are required to evaluate the damage, and also required good reparability. A beam with de-bonded diagonal reinforcements is very ductile and has good reparability even used as a short beam. To evaluate the load resisting system and the condition of damage level of a member, parametric experimental tests were carried out and a load-carrying model was proposed. After applying this model to the tested results, the design method with less damage was evaluated and investigated by FEM analysis.

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The authors propose two kinds of concrete rectangular stress blocks to be used for flexural capacity evaluation of high strength concrete columns up to 180N/mm^2 in concrete compressive strength. One is for the first peak capacity where the cover concrete spalls off, and the other is for the second peak capacity, following the first peak, calculated based on the core area. The calculation results using these stress blocks show good agreement with the test results which were obtained from high strength concrete columns tested under flexural compression. The evaluation by the stress block was found useful for structural design.

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Following the previous paper, this shows a step-by-step calculation method to estimate long-term curvature of concrete slab section on which certain moment force is imposed supposing that the dry shrinkage strain distributes along the section as an equal amount, i.e. rectangularly distributed. Compared to the values calculated according to the triangularly distributed shrinkage strain, they have small difference; especially the thickness of the member is large. Latter part of this paper describes the difference between the modified elasticity method which has been employed in Japanese building standard for reinforced concrete structure for long time as a simple evaluation method, and the step-by-step method depicted in this and the previous paper. This study shows that the modified elasticity method is effective as a rough evaluation, and the difference becomes larger as the amount of compressive reinforcement increases.

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An experimental study on real scaled one-bay-one-story frames, which is a wall-type structural system consisting of precast reinforced concrete panels with ribs, was conducted to construct nonlinear static analysis models used for the Calculation of Response and Limit Strength. Using the proposed models, nonlinear static analysis under reverse loading is executed. It was confirmed that the analytical results not only show good agreement with the test results for the load-displacement relationships of the frames but also evaluate the hysteresis damping. This paper shows the outline of nonlinear static analysis models and the analytical results.

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To obtain a better rebar arrangement, the author developed a plate-type mechanical anchorage system that attaches a rebar end using frictional welding. This system was used to anchor longitudinal rebar in the exterior beam-to-column joints of R/C buildings. To determine the usefulness of this anchorage system and test the basic characteristics of the anchorage mechanism, the author did three experimental studies. The first study is welding tests. The second study is pull-out tests of rebar with two sorts of plate-type mechanical anchorages from concrete block. The third study is experiments of exterior beam-to-column joint using frictional welding. Based on the results, the following facts were found. The joint part of frictional welding has larger strength than the rebar maximum strength. And the mechanical anchor method using frictional welding is possible to put it to practical use.

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For a small-scale steel rigid frame with steel wall subjected to cyclic load, a simple model characterized as incompatibility with the end of brace idealized for the wall is developed. The frame is composed of beam-columns considered for bending and shear deformation to clarify seismic interaction between the frame and the wall. Three kind of analyses in terms of the aspect ratio of the panel are conducted. Some numerical results of load-deformation relationships, deformations, damage states and so on of the structures are obtained. For each example, the results are mechanically discussed.

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In collaborative analyses, stiffness matrices associated with the DOFs at the boundaries need to be formed though a condensation procedure by individual programs. Such a procedure is time consuming, and even impossible when using commercial programs. To solve this problem, an improved operator splitting method, which treats the unbalanced forces as pesudo external forces in the immediate following step, is proposed in this study. The new method are applied to collaborative analyses of a three story braced steel moment-resisting frame. In the analyses, the lower parts of the columns are analyzed by a commercial FEM, i.e., ABAQUS, and the rests are analyzed by a frame analysis program NETLYS. The reasonable results suggest the modified operator splitting method is very effective for collaborative analyses.]

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A calculation method of the ultimate shear strength of steel reinforced concrete (SRC) columns based on the lower bound theory of plasticity is proposed in this paper. The shear resistances of the truss mechanism and arch mechanism are obtained. The ultimate shear strength is calculated applying the extended cumulative strength theory, considering the influence of shear on axial and flexural stresses. Predictions from the proposed equations are shown to be in good agreement with the test results of 43 specimens used normal strength materials and high strength materials.

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A series of studies have been conducted on the following subjects concerning the standards for judging seismic performances of ordinary seismic resistant, vibration controlled or seismic isolated buildings in JSCA performance menu, which are described in detail in the reference literature 2). 1) To establish the value to demonstrate safety limit corresponding ultimate limit state of structures; 2) to review the limit of margin I and II levels for each evaluation item; and 3) to review weighing factors for structural performance evaluation items. Revised standards for judging performances and the corresponding revision of weighing factors are described herein based on results of the study. Although the study is based on limited experimental and/or analysis data, authors believe that the proposed standards provide more rational bases for judging seismic performance evaluation of buildings.

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Rapid reanalysis of eigensolutions after modifications is a problem of considerable practical importance. Several methods have been developed to compute eigenvalues by using modified parts. This paper proposes a numerical method for calculating eigenvalues of modified system using the numerical solutions of unmodified system with the inverse power method. The advantages of the proposed method are examined comparing with the solutions of inverse power method by several numerical examples. The results obtained agree well with the exact solutions in short CPU time and this indicates that the proposed method provides efficient convergency.

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Using about 28,000 records from over 500 events up to August 2005, we determined an attenuation relation of JMA (Japan Meteorological Agency) seismic intensity, which is applicable to near source region. The determined attenuation relation was verified by comparing with data of recent earthquakes: the 2003 Off Tokachi, Off Miyagi and 2004 Chuetsu earthquakes of inter-plate, slab and crustal events respectively. Fairly agreement can be seen in these comparisons at close distance to the source. Iso-seismic intensity area by our relation is well corresponding to results of previous studies.

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