Polycarboxylate-type superplasticizer (PC), which is controlled its adsorption rate on the cement particles by changing the polymer structure, is proposed. It was found that PC whose adsorption rate is slow shows the excellent slump retentive ability, on the other hand the faster adsorption rate gives the superior water reducing performance. Also we found the adsorption rate depends on the quantity of polycarboxylic acid groups, which are the adsorption groups on the cement particles, per PC molecule. And the last the PC adsorption conformation on the cement particles was discussed based on the hydrodynamic radius and computer simulation of PC.

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For the purpose of optimizing the plan for seismic protection scenario in municipal unit, this paper proposes the strategic method for effectively and efficiently selecting the seismic hazard maps having significant impact on Nagoya city, Japan, as an example area in this study. In the first part, we make geographical database about 41 sheets of seismic intensity maps on Nagoya city and its population. In the second part, we select the extensive distribution of seismic intensity by use of the cluster analysis, and estimate the effectiveness and the efficiency of selected extensive distribution of seismic intensity. The result shows that nearly 99% of estimated victims in Nagoya city are able to be covered by only 2 maps selected in the strategic choice approach.

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In this paper first we analyzed statistical properties of the seismic indexes obtained by the standard method for low and mid-rise reinforced concrete (RC) buildings in Kyushu University. The total number of target buildings is 47. We also conducted microtremor measurements of these RC buildings to obtain their predominant periods as their fundamental dynamic characteristics. Then buildings were grouped by height (i.e., number of stories) and age and we tried to find formulae that connect predominant periods with seismic indexes of structures. As a result we found simple formulae and curves that can estimate at least the minimum value of the seismic index of a low- or middle-rise RC building based on the predominant period from microtremor measurement.

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This paper describes the results of shaking table tests on a slender base-isolated building model supported by four laminated rubber bearings to clarify the ultimate behavior when bearing fracture occurs. The results of the tests indicate that the ultimate behavior of the base-isolated building is roughly classified into two types; one is caused by buckling fracture of the bearing, and the other is a result of tensile fracture of the bearing. In the buckling type, one of the standards for judging the occurrence of buckling fracture is that the lateral deformation exceeds the value corresponding to the diameter of the bearing, and the aspect ratio of the building does not have much effect on the ultimate behavior. In the tensile type, tensile deformation becomes higher with an increase in aspect ratio, and the ultimate input level does not decrease. The building has a safety margin to fracture even if the aspect ratio becomes larger.

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A general method is proposed to predict seismic peak responses of steel structures with velocity-dependent dampers subjected to earthquakes based on equivalent linearization technique by means of static pushover analysis with three dimensional frame models. Damper elements installed in static analysis frame models are represented by combination of simple nonlinear elastic springs and equivalent viscous damping coefficients both obtained by a series of stationary vibration on analyses for various amplitude. This method is effective for any kinds and types of construction of dampers. Time history response analyses were conducted to ensure accuracy of this method.

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In a preliminary stage of architectural design, many case studies or collection of experience-based information on construction cost are required, because the decision made at the preliminary stage almost determines construction cost of the building. The authors, therefore, think that it is useful for designers to gather material on construction cost using optimum design method. In this paper, we propose an approximation formula to predict total optimum steel weight of 3D steel frame models with arbitrary brace placement.

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We proposed a simple method that estimate displacement of shield on excavating above shield and verified this method by two results that were measured under different ground structure and different plan of excavation. We get a few opinions by this verify and refer as follows.1) The shield displacement is predictable in two-dimension elasticity FEM analysis that considers the ground rigidity decrease by the excavation in the direction of the axis line and the decrease by the excavation is from initial rigidity obtained from PS logging. The bottom of decrease area should set as bottom of pressure bulb (σ_z=0.1p). 2) Value of shield displacement is estimated as that of ground at bottom of the shield.3) The three-dimensional effect of the excavation plan that have the longer side in the direction of the axis line is estimated multiply α (Ratio of analytical result in direction of axis line of digging center and analytical result in direction of crossing) by the analytical result in the direction of the axis line.4) The shield displacement is estimated by decreasing the ground rigidity the area modeled pressure bulb (σ_z=0.1/p) when the final excavation.

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Very strong ground motions (maximum acceleration 993cm/s² in the borehole seismometer point of -255m in depth) were observed in the Kashiwazaki Kariwa Nuclear Power Plant during the Niigataken Chuetsu-oki Earthquake on July 16, 2007. In this study, we tried to develop new method, which can simulate waveforms on free rock surface by using the bore hole records. We identified the underground structure model at the Service Hall from aftershock records observed in vertical array, using the simulated annealing method (Ingber(1989)). Based on numerical experiments it is identified that S-wave velocity and Q values of individual layers are inverted very well. Strong motion records of main shock observed by the bore hole seismometers were simulated by using one-dimensional multiple reflection method. In this study, non-linear effect is considered by introducing non-linear coefficient c (f) for under coming wave from surface. The maximum acceleration and phase characteristics in simulated waveforms are similar to the observed one. It means that our method is useful for simulate strong motion in non-linear region. Finally, strong motions on the free rock surface at the Service Hall during the main shock are simulated. The maximum acceleration of EW component on free rock surface is estimated to be 1,207cm/s².

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A linear Mixed Integer Programming (MIP) approach is presented for topology optimization of trusses with discrete variables under stress constraints. The objective function is the total structural volume. A systematic approach is developed for selecting the topology of each unit of a regular plane or space truss from the list of pre-defined traditional layouts. It is shown in the numerical examples that an optimal combination of the traditional layouts of trusses can be successfully found by solving a linear 0-1 MIP problem.

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There are many structures that are controlled their shapes and/or stress distribution by being actively varied the length of their members. Some of the structures with vibration control system, so-called variable geometry trusses and many of the tension structures are examples of such structures. One of the difficulties in the design and realization of such structural systems is how to grasp the relationship between the member length change, and their shapes and stress distribution. In this paper a simple and effective linear inverse theory for the control of such structures is described. Then its validity is proved by showing some numerical examples and the comparison with the results of real scale tests of a tensegrity frame.

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A new approach is proposed for shape optimization of shell structures, where requirements on the aesthetic aspect and the constructability as well as the structural rationality are simultaneously considered in the problem formulation. The surface shape is modeled using a tensor-product Bézier surface to reduce the number of variables, while the ability to generate moderately complex shape is maintained. The strain energy is used to represent the mechanical performance, and the aesthetic properties and smoothness of the surface are quantified by algebraic invariants of the surface. The condition of the developable surface is ensured by incorporating the constraints on the principal curvature. The sequential quadratic programming method is used to obtain the optimum shape of shell structures. The effectivity of the present approach is confirmed through several numerical examples, and the characteristics of the results are discussed.

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We propose a technique for obtaining the skeleton curve of moment-rotation relation at the column base of traditional timber buildings form local compression tests of wood elements. In the local compression experiment, a rotated wood specimen is pressed into foundation stone keeping the rotation angle constant. From this experiment, we obtain the relationships between the amount of reaction force from the foundation stone and its acting position for the specified rotation angle. Noting that the moment at the column base can be expressed by multiplying the amount of the reaction force and its position of action, we can predict the moment-rotation angle relationship at the column base from a set of the local compression tests, where the rotation angle is changed as an experimental parameter. The proposed approach was verified by comparing the estimation with the results of horizontal cyclic loading test under a constant axial force. The size effect was also studied in the cyclic loading test.

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Porous fence is an effective device to control the wind flow and to reduce the wind force. The aerodynamic characteristics those necessary to wind resistant design are usually examined by experiment because of the variety of materials and the difficulty of simulating the flow in and around the porous objects. Here we present a practical method for numerical prediction of unsteady flow around a fence. Reproduction of the configuration of solid obstacles in the fine mesh discretization is a direct way to make numerical calculations on porous objects. However, calculations using the fine mesh increase the computational load and can cost a lot of time and money. In order to reduce these factors, we applied space averaging to the Navier-Stokes equations and derived filtered equations with a subgrid scale turbulent modelling for the Large Eddy Simulation. We adopt the turbulent modeling to a porous fence and calculate the space-averaged property of flows with coarse meshes without a heavy computational load. The model drag coefficient was examined by a calculation with fine mesh and by an optimization with coarse mesh. Finally, we also present a calculated turbulent field around a porous fence placed on a flat plane and compare the result to a wind tunnel test. Simulated flows showed good agreement with experimental data.

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The purpose of this research is to propose a method for the evaluation of the shearing performance of the mud wall based on the load carrying mechanism of the mud wall. It is confirmed by our current research that the fracture mode of the mud wall depends on its wall length. And the initial stiffness and the load bearing capacity of the mud wall is not proportional to the wall length. It is presented in this paper that the envelope curve of the mud wall which has an arbitrary wall length is interpolated between the envelope curves that have different fracture modes each other, and the validity of this prediction method was experimentally confirmed.

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This paper deals with a mechanical model to simulate the random hysteretic characteristics of wooden frame structure precisely. The first part describes a universal modeling method based on load-deflection relations obtained from static cyclic loading tests. This modeling method, which is called extended-normalized-characteristic-loop (ENCL) model, is capable of obtaining numerous model parameters automatically from cyclic load-deflection relations and simulating hysteretic energy dissipation precisely. The second part includes static random loading tests to confirm the internal hysteretic characteristics of normalized characteristic loop of the structure. In view of the property, the rule of stiffness-degradation due to a repeated random loading was also discussed. The last part is analytical study to confirm the availability of the proposed ENCL model to simulate seismic response behaviors of a structural plywood wall that is subject to an inertial loading test. It is shown that the computed results with use of the proposed ENCL model are in good agreement with the experimental results.

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Recent approaches to the design of reinforced concrete members have paid attention not only to shear failure as a primary cause of collapse, but also to shear damage from the viewpoint of serviceability and durability. Tests were performed on RC columns having axial load ratios of 0 to 0.3, and shear reinforcement ratios of 0.29% and 0.63% in order to study the influence of axial load and shear reinforcement upon the shear-transfer mechanism while shear damage was in progress. Resistance against shear damage increases with an increase in shear reinforcement, but the shear-transfer ability, due to the concrete contribution, decreases with an increase in shear reinforcement and axial load. A method for evaluating shear damage has been proposed based on the shear-transfer mechanism of concrete and reinforcement. FEM analyses have been also carried out to verify the transition of the shear-transfer mechanism estimated by the proposed method.

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In this report we described on obtaining the load-deflection curve of the restrained one way composite slabs and compared the curve of calculated results with the curve of experimental values, then investigated.
As a result, the curve of a calculation value showed a tendency to match a curve of experimental value well approximately.

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Non-linear FEM analyses for RC shear walls with multi openings tested by the authors were performed to simulate the experimental results such as hysteresis loops, failure process and stress distribution of reinforcing bars in this paper. The accuracy of the analytical modeling and constitutive law of materials used were also examined through the analyses. Good agreements between test and analytical results were found until the maximum capacity. It was indentified that the failure mode and shear strengths of the RC shear walls with multi openings were significantly affected by the difference of the number and layout of openings.

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Buckling Restrained Braces (BRBs) are commonly used as ductile bracing elements in seismic design. A key limit of BRB is overall flexural buckling. However, their effective buckling lengths are affected by the stiffness and strength of their connection zones. In this paper, each connection zone is modeled as two rotational elastic springs at gusset plate and two rotational elasto-plastic springs at the end zone of the restrainer. Their stiffness and strength are investigated by mock-up experiments and analyses, and their evaluation methods are proposed.

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In this study, the cyclic hysteretic characteristics and collapse mode of hybrid structure, which is constructed of light gauge steel construction and steel moment frame, is cleared by static cyclic loading. These hybrid structures are composed of different restoring force characteristic components, steel moment frames and shear walls. Using this experimental results, structural characteristic factor (Ds) is evaluated by current methods, and it is shown that Ds factor by current methods are not agreeable to actual condition of hybrid structures. So, a new evaluation method for adapting to hysteretic characteristics of hybrid structure is presented.
Additionally, the seismic response analysis is done by using the hysteretic characteristics of steel moment frame and light gauge steel house shear wall which are obtained from experiments. The Ds factor corresponding to the allowable story drift angle is evaluated by cumulative plastic deformation magnification. This Ds factor is compared with the Ds factor getting by new evaluation method, in order to show that the new evaluation method is correct and available.

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The safety of steel construction building cannot ignore effect of wind load because of an increase in high-rise building. Therefore, fatigue damage by wind load is important issue for steel frame. Currently, Miner's law is used generally for estimation method of fatigue life when stress amplitude varies as actual load. However, the recent studies report that the estimation of fatigue life by using Miner's law tends to exaggerate fatigue life. Therefore, we investigated the effects of the difference of the number of the steps, the damage proportion and the turn to give about amplitude on fatigue life by carrying out fatigue test. According to these effects, we proposed estimation method of fatigue life.

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Column bases are most important parts in strength and deformation capacity in the estimate of seismic resistance of steel framed structures. A lot of research works has been made, however, the relationship between the structural behavior and the behavior of column bases has not been made clear yet. In this paper, the analytical model of fish-bone of frame is applied and the experimental results of column bases is introduced. Five-storied weak-beam type frames are taken. The bottom of columns is equipped with actual column bases. Damage distribution and deformation of the column bases are analyzed in terms of the intensity of seismic input. As a references, two type of idealized fundamental frames are introduced. Based on the result of analysis, the design method of column bases for low-rise steel frames is summarized.

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The damage evaluation method was proposed, that natural period transition of a steel-frame building may be used to assume damage or maximum deformation after an earthquake. Nonstructural members which had not been evaluated as a proof stress, sometimes influence natural period of buildings. The unloaded horizontal stiffness after an earthquake was grasped by the frame experiment and the frame experiment with brace or nonstructural members. And the eigenvalue analysis was carried out to show natural period gets longer as seismic deformation becomes big. This depends on the data showing the unloaded horizontal stiffness of a frame is almost constant however that of a brace, an RC nonstructural wall or a PC wall falls fast. And it is confirmed that the natural period transitions of patterned steel- frame buildings of thermal power plants are effective to evaluate the damage after an earthquake.

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This paper describes experimental and analytical studies on the fire resistance of a reinforced concrete slab under the negative bending moment. As the result of fire resistance tests, it became clear that the reinforced concrete slab under the negative bending moment had the outstanding performance for the fire heating. The bar arrangement of main reinforcement and slab thickness influence the fire resistance greatly.The analysis result was well in agreement with the experimental results. Parameter study was performed and the influence of the bar arrangement and slab thickness on the fire resistance became clear.

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