This paper aims at clarifying creep behavior of concrete involving expansive (expansive concrete) additive in early age. This clarification is achieved via proposing a new creep model for expansive concrete based on observation in early age strain behavior. This model is verified using compressive early age creep experiment for expansive concrete, in which ages at loading are varied in 0.5,1.0 and 2.0 day. The experimental results are reasonably reproduced, and the accuracy of the proposed model is demonstrated. Finally, the proposed model is found to be utilized for quantitatively evaluating chemical pre-stress generated in restrained expansive concrete elements, which is very effective to control shrinkage cracking in reinforced concrete structural elements.

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The relationship between carbonation depth and cover thickness is often applied as a criterion of the evaluation of deterioration of reinforced concrete building. This report shows the result of an analysis of the carbonation progress of concrete based on investigation a lot of existing buildings. As the result, we clarified the actual situation of the carbonation speed, and relationship between the compressive strength and the carbonation speed of every kind of finishing materials. And we quantify the carbonation inhabitation effect of finishing mortar, about 0.8 times of the thickness of the mortar is equivalent to the cover thickness of concrete.

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It is important that clarifying water distribution and moisture movement in the brick masonry wall quantitatively, so as to design the mitigation method for efflorescence of historical brick masonry buildings reinforced with concrete. For this purpose, model wall specimen was built in the laboratory and observation of efflorescence was carried out. And the water distribution in the model wall was measured by using TDR method in the test. It was considered that the higher water content of inner brick masonry wall become, the more soluble salt moved from the interface of concrete to the surface of brick masonry wall. The numerical simulation of water movement in the model wall was performed with the Delphin4 program developed by TU Dresden. It seemed that the simulation results reproduced the tendency of measured moisture profiles in each position.

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The authors have presented a prediction method of fluctuating wind force with no static component induced an elasto-plastic response based on an energy balance, and shown its validity. However, the method was limited to the case of a narrow-band random process. This paper presents a prediction method expanded to the case of wide-band random process. A prediction method for a mean wind force induced response is also presented. The authors show that wide band flactuating wind force induced elasto-plastic response is determined by not only energy balance for resonance component but also equilibrium of force between a quasi-static component of wide-band fluctuating wind force and an elast-plastic system. The agreement between the predicted value and results of time-history analysis was finally confirmed.

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The optimal allocation of damping in coupled buildings and its control efficiencies are discussed in this research. For a given total damping, the optimal connecting damping and connecting stiffness that result minimum magnification factors for stable vibrations are searched from numerical computation. It was found that allocation of total damping for connecting damping gives maximum control efficiencies when the total damping is smaller. While for larger total damping, the required connecting damping decreases, and more damping should be allocated within buildings. The efficiency of coupling decreases with the increase of total damping, and is defined by an equivalent damping factor. Using equivalent damping factor and equivalent vibration periods, earthquake response of the coupled buildings may be satisfactorily evaluated by response spectra of single degree freedom system.

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The maximum response of structure under an earthquake is closely related to the maximum response spectrum (S_V-spectrum). The cumulative plastic deformation is related to the energy spectrum (V_E-spectrum). The relationship between S_V-spectrum and V_E-spectrum is influenced by the scale of an earthquake or the time of duration of an earthquake. On the simple assumption that an earthquake consists of the repetition of a single elemental earthquake with the number of repetition of f, the relationship between S_V and V_E spectra is clearly described with the relationship of that in the elemental earthquake and f.

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The end faces of laminated rubber bearings are subjected to large rotation in cases where the beams to which the bearings are attached are low in stiffness or are omitted. Since there have been few studies on the effect of end rotations on the mechanical properties of bearings, many points remain unclear. In this study, based on the Haringx theory, exact load-deflection relations are derived considering end rotations. Then, simplified expressions are derived as a first approximation, which make it easy to understand the effect of end rotations on the mechanical properties of bearings. To show another advantage of these approximate expressions, a bearing rotationally constrained by a superstructure is analyzed. It is shown that the solutions can be easily and accurately obtained by using these expressions, In addition, applicable deformation limits of these expressions obtained by elastic theory are presented. Based on numerical studies, effectiveness and accuracy of the above expressions are presented.

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This paper deals with soil-structure interaction of pile foundation, piled-raft foundation and embedded foundation on pile group. The impedances and foundation input motions are analyzed by the thin layered element method and flexible volume substructure method. The comparison among piled-raft foundation, pile foundation and raft foundation and the comparison among embedded foundation on pile group, piled foundation and embedded foundation are made. Also, the effects of the joint at pile head, the extension at pile tip, the size of raft of piled-raft foundation and the contact condition between soil and the bottom of mat on pile group are discussed. The bending moments in piles subjected to harmonic loads and S-wave input motion are also examined.

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During a large-scale inverted construction of super-high-rise building, behaviours of ground and underground structure were monitored on site. From rebounds and settlement data, stress-strain relations of ground were evaluated and discussed. To adequately model the stress-strain relations derived from the monitoring results, dependencies on both confining stress and strain should be considered simultaneously. A method for estimating stress-strain relations of ground introducing a concept of stress-strain curve under constant confining stress. Behaviours of ground during construction as well as the sand triaxial test results were well represented by this method.

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This paper investigated earthquake responses of the latticed domes supported with braces of deteriorated stress-strain relationships due to buckling, followed by a proposal for estimation method of static seismic loads. The method for proposal is based on an equivalent linearization method, where nonlinear stress-strain relationships are linearized using an equivalent stiffness. First, two main modes, obtained in the equivalent linearization, were selected and superposed for representing the dynamic behavior, and two types of static seismic load depending on the intensities of input earthquake motions were proposed: One is a seismic load considering mainly the effects of horizontal sway motions and the other one is a seismic load reflecting the effects of the anti-symmetric motions induced by horizontal earthquake motions. Second, the seismic loads were applied in the pushover analysis of the domes, and the responses were compared with those calculated using a time history dynamic analysis. Finally, the proposed method was proved accurate and efficient for estimating static seismic loads as well as for structural proportioning of the members of latticed domes.

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The main objective of this research is to develop the vibration control system of several modes for large span structures using distributed MTMDs (multiple tuned mass damper). In this study, to determine the arrangements of MTMDs, the method using the superposed shape of controlling modes is newly proposed. In this paper, the design method of MTMD bandwidth for controlling several modes is proposed by using the existed optimal bandwidth for controlling one mode. Then, we propose a rough applying limit of the method by comparing the optimal MTMD bandwidth with the designed bandwidth. Lastly, we applied the proposed method for a dome model and confirmed good performance for controlling responses of whole parts of the structure.

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A temple is not considered to be capable of resisting large earthquakes because of its poor resistant wall and heavy roof. In this paper, we propose a simple analytical model on a temple and estimate it's paremeters taking the case of four temples standing at Shizuoka prefecture in order to obtain the dynamic response during earthquakes. The main results obtained from this sudy are as follows. An one-side eccentric axis model considering the sway and rocking deformation of soil-structure system could represents the dyanamic characteristics of temples. In this model, mud-plastered wall and column which has rotational stiffness at each end of it are horizontal resistant factor. The paremeters of mud-plastered wall are decided from the results of experiments. The rotational stiffnesses are evaluated as 10,000 kN.m/rad depending on coincidence of the natural frequency of analytical model with that of existing temple. These walls and columns are considered to be connected as parallel.

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In order to examine the seismic behavior of Japanese traditional tea ceremony room subjected to an intense earthquake, We have conducted a series of shaking table tests using a full size model of Myouki-an Tai-an in Kyoto the national treasure, the bottom of columns of which are not connected to the foundation. This is one of the most important features of Japanese traditional wooden houses and is assumed that the upper frame may move from the foundation and reduce the damage in the event of a strong earthquake. Following results have been obtained. 1) A half of the Input-energy estimated to dissipate through the friction between bottom of columns and foundation. 2) According to the decrease of the rigidity of the model due to the accumulation of damage, energy absorption due to hysteresis became large compared to that by frictional resistance of the base. 3) The model moved more easily if the vertical acceleration is combined with horizontal components in comparison with the case the vertical acceleration is not exist.

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Static and dynamic analyses were conducted for twelve-story RC frames with various beam strengths. Story-safety-factor was defined at each story as the ratio of the ultimate story shear force under push-over analysis and the sum of the strengths of the columns in the story. The story-safety-factors in the diagonal direction were approximately 0.7 or 0.8 times those in the direction of the beams. The story-safety-factors were more effective in predicating story collapse than the column-to-beam strength ratios. When the story-safety-factors in each story exceeded 1.5 in a direction, story collapse did not occur when excited in that direction.

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The RC column with wing-wall is vulnerable to large seismic excitation as the presence of wing-wall to original column section, the shear span to depth ratio becomes shorten and the seismic input force is considerably increased, and hence, the insufficient transverse reinforcement in that wing-wall column may lead to undesirable brittle shear failure. The strength and ductility of this shear critical wing-wall RC column can be extremely enhanced by transverse confinement which consequently imputes the benefit of shear strengthening. Considering this fact, a seismic retrofit concept of thick hybrid wall utilizing additional mortar sandwiched by steel plates and PC bar prestressing for RC column with wing-wall either one-sided or both-sided is proposed in this paper. The main goal of this research is to verify whether the proposed retrofit technique is effective or not in respect of enhancing the lateral capacity and ductility. The assessment of the proposed retrofit technique is experimentally investigated and also analytically evaluated. Moreover, to suggest the design guidelines of the proposed retrofit technique for wing-wall RC column, the simplified equations to calculate the flexural and shear strengths, and the selection techniques of steel plate thickness as well as diameter and minimum number of PC bars are also proposed in this paper.

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Experiments and 3-D FEM analyses were performed on reinforced concrete columns laterally prestressed by the shear reinforcements to study the influence of the active confinement upon bond splitting strength and crack behaviors. Many strain gauges were glued on main bars to investigate the bond stress and the width of every crack over transverse hoops were measured by a microscope. The lateral pressure increases the bond splitting strength as well as the shear crack strength and the ultimate shear strength, and decreases the widths of cracks. The FEM analyses using bond-slip model can evaluate the shear crack strength and ultimate shear strength, and provide valuable information about the effect of the active confinement on the bond behaviors by evaluating the intensity of confinement in tri-axial state of stress with minor principal stress and equivalent confining pressure.

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Nonlinear finite element dynamic analyses were conducted for the RC walls subjected to hydrogen explosive load in order to verify an applicability of the analysis method by comparison with experimental results obtained from past explosion tests. The analytical results show good correspondence with the test results. It is concluded that the nonlinear response of the walls subjected to the hydrogen explosive load can be estimated by the finite element model with sufficient accuracy. Furthermore numerical study was carried out with various wave forms of the explosive load. As results, it is found that the maximum displacement in the nonlinear response was not influenced on by the wave forms, but depends on the impulse of the explosive load. It is also found that negative pressure of the explosive load is needed to be considered to evaluate the maximum wall response accurately.

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Tubular sections are commonly used for truss structures or diagonal braces, because they have higher moment-of-inertia comparing to open cross-sections with the same area. However, their cumulative cyclic deformation capacities after buckling are known as quite small comparing to H-sections, because strain concentration occurs with local elbow buckling. For evaluating seismic performances of such structures, cumulative cyclic deformation capacity of braces before fracture is essential. In this paper, cumulative cyclic deformation capacity of tubular braces with local buckling is researched by cyclic loading tests with various slenderness ratios and thickness ratios. Their strain concentration mechanism is researched thorough various analyses, followed by proposing easy evaluation method of cumulative deformation capacity.

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Using numerical analysis based on a finite element method employing axisymmetric thin shell elements, the beginning and progress of local buckling in circular concrete filled steel tubes (CFT) subjected to cyclic axial loads were investigated. The numeric analysis revealed that the infinitesimal changes in deformation of a tube occurred from the start of cyclic loading, and at last the changes lead the severe buckling mode and the deterioration in strength of the tube. From the analytical results, a formula to predict the start of cyclic local buckling for CFT was proposed in a manner of the accumulated damage law. The formula gave the lower bound for data from tests on actual cold-formed steel tubes. The similar formula was also proposed for rectangular CFT members.

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The intrinsic ultimate fire resistance is clarified for seismically designed steel frames by the derived theoretical ultimate temperatures and a series of refined numerical solutions. For steel frames exposed to compartment fire, stress redistribution works and helps to lift the heated and buckled columns upward and to increase the ultimate temperatures and fire resistance. It is found that seismic design adds better fire resistances to a frame generally to some extent. However the seismic design with a higher plastic deformation capacity and therefore with a lower base shear coefficient weakens the frame in ultimate temperature due to resulting less stress redistribution capacity.

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