The effects of chemical structures of graft copolymer on cement-dispersing performance were investigated in order to elucidate the fluidizing mechanism of polycarboxylate-based superplasticizer containing polyethylene oxide graft chains. Graft copolymer having longer graft chains showed better dispersing stability at small amount of adsorption. Moreover, the adsorption study indicated that the graft chains were stretched as increasing the adsorption density. From the experimental result of the extension for graft chains, the interparticle interaction according to the steric hindrance theory can be explained the effect of length of graft chains on cement-dispersing ability and thus we proposed the modified steric stability model.

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In this paper, properties of compressive strength in aging concrete are deduced from the examined data collected through the seismic diagnosis. The data were taken from examination on core samples removed from existing RC buildings. Through the statistical analyses on those data, following findings were obtained : 1. The distribution of the compressive strengths could be expressed by a log normal distribution curve. 2. The relative compressive strength expressed as percentage of the specified design strength was 1.28, and the percent defective was approximately 30 percent in average ; the former was lower and the latter was higher than those of the companion data in Kanto and Kansai districts.

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This paper proposes the practical measurement method of floor vibration and the criterion to prevent the complaint from occupants. Using twenty actual wooden and light weight steel-frame floors, the vibration excited by human walking and previously developed "Excitation and Perception Apparatus" is measured. The applicability of the apparatus for actual houses is confirmed by comparing the vibration measurements. The relationship between the vibration measured by the apparatus and the data on the complaint is investigated by using sixty-eight actual floors. The proposed measurement method and the criterion enable to utilize the previously proposed evaluation method of floor vibration.

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The purpose of this study is to present the validity of method to keep the slip resistance with fibered footwear by setting up convexity on the floor. First, we made sample floors which had convexities with several figured and measured C. S. R (Coefficient of Slip Resistance) with slip meter named "O-Y・PSM" developed by H. ONO. We presented the relation between C. S. R and elements of convexities figuration. Second, we established the validity of the method from a view point of stumbling and the pain caused by contact with the floor. Finally, we presented the validity of floors with convexity to keep the slip resistance with fibered footwear.

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It is a fundamental task to determine the distribution of basic random variables in structural reliability evaluation. In the present paper, a three-parameter distribution, directly defined in terms of mean value, deviation and skewness, is suggested. The new distribution can be applied (1) as a candidate distribution in fitting the statistical data of basic variables and generally presenting two-parameter distributions with small skewness, (2) to realize normal transformation and generate random samplings for random variables with unknown cumulative distribution functions in order to include them into structural reliability analysis, and (3) to provide a moment reliability index for the cases where the first-three moments of the performance function can be easily obtained. Some numerical examples are presented, the simplicity, generality and flexibility of the distribution are investigated, the applicability and efficiency of the distribution are demonstrated, and the distributions of some basic random variables are discussed.

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This paper presents a new analytical method in the evaluation of the safety index and the load and resistance factors of framed structures with resistance deterioration due to aging under load combinations consisting of dead, live, snow, wind and earthquake loads, applying the advanced first order and second moment method with the statistics of the resistance of framed structures which has survived up to time τ, instead of evaluating the exceedance probability of the maximum value of combined loads. The expected value of the load and resistance factors of framed structures modeled as series system is suggested, and the effect of resistance deterioration and correlation coefficient between the resistance of the elements on it is described with numerical examples.

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The effects of rupture directivity on strong ground motion are evaluated by ground motion simulation based on the stochastic green's function. For evaluating the influence of the directivity effect in attenuation relationships, the directivity effect factor D is introduced, which is the ratio of the amplitude of the simulated motion by the average amplitude from the attenuation relationship. The results indicate that, for earthquakes with vertical and unilateral faulting, there are strong directivity effects on peak ground acceleration and peak ground velocity. The distributions of D value are represented by simple functions. By using the factor, the ground motion intensity predicted by an attenuation relationship can be corrected considering the directivity effects. The method is applied to the records observed during the 1979 Imperial Valley, California, earthquake. The results show that the predicted value by the proposed factor matched the observed one well, and suggest that the proposed method is effective for evaluating the rupture directivltv effects.

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Satellite and airborne remote sensing, which can easily monitor a large area with high resolution, can provide effective spatial information to detect earthquake-induced damage. As a sensor installed on satellites JERS and ERS, synthetic aperture radar (SAR) is one of the most promising technologies since it is not affected by clouds. One of distinctive characteristics of SAR systems is their capability of recording both amplitude and phase of the backscattering echoes from objects on the earth's surface. In this paper, we investigated the microwave scattering characteristics of areas damaged by the 1995 Hyogo-ken Nanbu (Kobe) earthquake using ERS/SAR images for the purpose of possibility of extracting earthquake damage distribution by satellite SAR. According to the difference in backscattered intensity and spatial correlation of SAR images taken before and after the earthquake, we found that the characteristics of the backscattering properties of damaged areas showed significant variations. The relationship between building damage and the SAR images was found to be related to the damage level. This trend in areas of heavy building damage was revealed when the backscattered intensity and the correlation of pre- and post-event images became low. The damage distribution extracted by discriminant analysis based on backscattering properties agreed with the results of an actual damage survey. Therefore, the images obtained by remote sensing SAR could be a powerful tool for post-disaster management.

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The 1855 Ansei-Edo earthquake caused severe damage to Tokyo (Edo) metropolitan area. The damage was the next to that in the 1923 Kanto earthquake. In this study, source parameters of the 1855 Ansei-Edo earthquake were estimated by obtaining a good match between the simulated strong ground motions by the empirical Green's function method and the macroseismic data (isoseismal map). The hypocenter of the earthquake is most plausible near the border of Chiba and Ibaraki prefectures at a depth of 68km, near the upper surface of the Pacific plate. The magnitude of 7.4 is the best estimate for interpreting the macroseismic data.

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It is very important to estimate the distribution of seismic intensities for regional earthquake damage prediction about future big earthquake. The seismic intensity is strongly influenced by subsurface ground condition and basement irregular boundary condition. Although we usually estimate the site effect, predominant period and amplification, based on 1-D (one-dimensional) analysis method in order to predict the seismic intensity. Attention is focused on Nishinomiya-city in Hyogo pref., Japan, and the present paper considers the micro-zoning study for seismic intensity. Nishinomiya-city was suffered serious damages and four areas of this city recorded the highest degree in Japanese seismic intensity scale (IJMA=7) in 1995 Hyogo-ken Nanbu Earthquake, Japan. We tried to make two micro zoning maps of seismic intensity distribution in Nishinomiya-city by 1-D and 2-D (two-dimensional) soil response analysis. We compared between these maps and the evaluated seismic intensity distribution by JMA just after the 1995 Hyogo-ken Nanbu Earthquake, and the rate of the razed wooden house.

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This paper shows a method of converting a multi-story building into the equivalent single degree of freedom (SDOF) system, which can be applied to performance-based seismic evaluation methods such as the Capacity Spectrum Method. The feature of the converting method is to use information obtained from non-linear push-over analysis. The validity and applicable scope of the converting method were examined through the earthquake response analyses for several regular and irregular shaped buildings in which the responses of the equivalent SDOF system and the multi degree of freedom system were compared. The analytical results showed that the earthquake responses of not only regular shaped buildings but also irregular ones can be predicted by using SDOF system converted by the proposed method. For relatively high-rise buildings, however, the higher mode effect should appropriately be considered to the response of SDOF system.

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A management method has been presented for basement construction planning using statistical inference theory. Based on the measured deflection and stress of temporary earth retaining wall, main planning stages should be divided into 5 stages that are considered to be dependent on 3 to 8 temporary factors. The mutual relations between each factor for same stage and/or between different stages have been studied using statistical inference and regression analysis. Conclusions have been clearly shown as follows. 1. The managed value for planning of the deflections and stresses of the temporary earth retaining walls should be determined more carefully for the cases of soft layer or high viscous soil 2. The regression equation-based correlation is good (the coefficient is about 0.8) for highest stresses of basement construction, and the construction's planning factors.

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This paper describes modeling methods and the results up to the ultimate capacity by three global FEM analyses of a 1/4 PCCV test model subjected to increasing internal pressure. At first, a tendon friction model that can evaluate the friction effects between concrete and unbonded tendon is proposed. Secondly, the global analyses with an axisymmetric model and two types of 3D-shell models that use the tendon friction model are performed. Finally, the prediction of the nonlinear behaviors and the potential failure patterns of the test model are discussed in details.

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In general, a bolted joint system has been applied to the joints of a wooden single-layer space frame. In this structure, the authors have been studying the influence of a bolted joint looseness, furthermore, have suggested that a bolted joint looseness should be substituted an axial and a bending rigidity in the analytical model. In this paper, we have described the results of buckling tests for a wooden single-layer space frame with a bolted joint system on a hexagonal plan. In this study, the joint of test specimens were consisted of one-bolt, two-bolts and four-bolts. Finally, as the comparison between analytical results and test results, the analytical model of a bolted joint with a compressive strain inclined to the grain was confirmed.

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This paper presents numerical analysis procedures to evaluate static elasto-plastic behavior of wooden timber structures under horizontal loadings by using a ready-made structural analysis program. To evaluate the special property of structures, following models are used ; 1) virtual floors without in-plane rigidity to evaluate stiffness and strength of hanging and spandrel walls, 2) wall stiffness reduction factors to evaluate the semi-rigidity at end connections of the columns and girders in the axial direction. Numerical values needed for each models are obtained from loading tests. The validity of profosed models are confirmed by the results of loading tests.

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Up to now, on beam-to-column welded joints built up at works, it has been reported that non-scallop method improves on deformation capacities more than conventional scallop method. However, there are various forms in beam-end details for non-scallop method, and the difference of deformation capacities to them doesn't always become clear. In this paper, from the results of cyclic loading test on the specimens modeled on beam-to-column welded joints, it investigates the effects which the difference of beam-end details for non-scallop method makes on deformation capacities. Finally, it proposes beam-end details for non-scallop method, being excellent in deformation capacities, about each of interior diaphragm type, through-diaphragm type.

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With the object of investigating the effects of vertical ground motions on column axial force of steel frames, both on-line response tests using one-mass models and inelastic response analyses for multi-story frame models were carried out. It was shown that the maximum axial force is determined mainly by strength properties of frames, vertical static loads and the maximum fluctuating axial force caused by vertical vibration. A method for simply estimating the maximum yield axial force ratio of both inside and outside columns for frames with columns all of which have nearly same yield axial force ratio under vertical loads, when they are subject to both horizontal and vertical ground motions simultaneously, was formulated.

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This paper deals with the high-strength bolted friction-slip joints using the carbon steel flat bar with the slotted hole. To clarify the slip load, the dynamic hysteresis characteristics and the permissible region for the scuffing, the dynamic tests under the constant-amplitude displacement-cycling were conducted. The test parameters are the location of the slotted hole, the slip velocity, the bolt clamping force and the steel grade. The results indicate that the energy absorption capacity of the joints where the outer plates have the slotted hole is larger than that of the joints where the inner plate has the slotted hole, the hysteresis loop is the rigid-plastic type and the cumulative slip deformation of the cold-finished carbon steel flat bar is significantly affected by the bolt clamping force and the slip velocity.

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In the 1995 Hyougoken-Nanbu earthquake, brittle fractures of beam flange in the vicinity of H-shaped beam-to-boxed column (HBBC) moment resisting connections were widely observed. The authors proposed a horizontal haunched beam to improve deformability of the connection. On the other hand, the use of the high toughness material reportedly gives good deformability to the connection by preventing its rupture without a special device such as a haunch. This hinted the use of a simpler method like a cover-plate stiffner to beam-end with high toughness material. However, there is few research on the nonelastic behavior of the cover-plated beam-to-box column connection. Therefore, loading tests were carried out by the authors. The specimens had no defefct because of employing the new welding process and the nondestructive detecting method using a SH ultrasonic wave. In the tests, four specimens having two types of stiffened method, cover-plate and horizontal haunch, were cyclically loaded. The test results indicated that the cover-plate was more effective than the horizontal haunch to increase in deformability of the HBBC connection. The design and calculation method for the haunched beam also could be applied to the cover-plated beam as well as the initial stiffness, the yielding strength, and maximum strength. However, the selection of the column diaphragm thickness needs more reseach on the stress-transition from beam to diaphragms.

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Experiments were conducted to understand the effects of a confined space and ventilation on properties of plume and near field of fire sources using 3 types of model tunnels. The first one is a scaled tunnel with square and/or arched cross-section of 0.09 m^2 with length of ranging from 0.9 to 23m. The second one is, reinforced concrete tunnel, of 0.6m wide, 1.8m high and 12.8m long. The last one is a full-scaled tunnel of the cross sectional area of 5.4 m^2 with arched shape and 400m long. Temperatures in the near field of flame and plume were measured changing the bulk ventilation velocity. Estimation on maximum temperature and its position that appears in the down-flow region and beneath the ceiling under forced ventilation were modeled, and also modeling on the correlation for the critical velocity was deduced. Froude modeling was utilized on the relations between the excess temperature and/or upward velocity along the plume axis under natural ventilation condition and that is compared with results obtained in the free boundary condition.

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The effect of pressure dissipation due to structure-ice gap on the hydroelastic response of fixed hollow cylindrical structures during earthquakes in ice-covered seas is investigated. The elastic shell theory is used for structures, whereas the potential flow theory is applied to fluid domain. The sea ice is idealized as the semi-infinite rigid boundary that is connected to the annular free surface between structure and sea ice. The hydrodynamic pressure is obtained in closed form by domain division method. Wet mode properties in beam mode of hollow cylindrical structures are evaluated by Rayleigh-Ritz method. The mode superposition approach is used to calculate the hydrodynamic pressure distribution and earthquake response against horizontal ground motion. Numerical examples are presented to illustrate the changes in hydrodynamic pressures and earthquake responses due to the width of structure-ice gap.

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