The reduction of CO₂ emission from various productions and service processes has been already recognized to be not enough, CO₂ sequestration is necessary for decreasing the concentration of CO₂ in the atmosphere. In this study, the author proposed a new method for sequestrating CO₂, which encloses CO₂ bubbles into foamed concrete, and then investigated the strength, water absorption, drying shrinkage, alkalinity, CO₂ uptake caused by the carbonation, and micro-structure, etc. of CO₂ -foamed concrete (CFC) and Air-foamed concrete (AFC) using different kinds of cement. The experimental results show that (1) Mixing CO₂ bubbles into concrete didn't harm 28-days compressive strength and flexural strength in case of using ordinary Portland cement, and didn't increase drying shrinkage of foamed concrete. (2) The pH of CFC with 3 months age was kept to be more than 12.0, when CO₂ content was below 60% by volume, (3) Internal CO₂ bubbles yielded a little increase of CaCO₃, and (4) CO₂ sequestration in CFC was mainly structural trapping rather than carbonation.

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 In this paper, applying several kinds of adhesive waterproof paper to a wooden lath-mortar external wall was suggested. The adhesive waterproof paper has an adhesive layer and elasticity. Therefore, it is thought that the wall which is applied adhesive waterproof paper has performance to prevent exfoliation of mortar caused by earthquake. In addition, it is thought that the durability of the wall improves. For the purpose of evaluating the effect by the application of the adhesive waterproof paper, some evaluation experiments were performed. As a result, it was cleared that the adhesive unity against the off-plate direction force and the rust prevention of staples of the wall which was applied adhesive waterproof paper can be improved.

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 In this study, structural response analyses with ground-motion time histories are conducted for an RC structure. These ground motions incorporate the uncertainties of macro-scopic and micro-scopic seismic-source characteristics. The purpose of this study is to examine the relationship between the uncertainties of seismic-source characteristics, seismic intensities and structural responses. As a result, it is clarified that seismic moment M₀, stress drop Δσ and Q-value coefficient C_Qc positively correlate with seismic intensities and maximum structural responses. It can also be seen that M₀ highly correlates with velocity, displacement and energy indices of seismic intensities, and that Δσ and C_Qc highly correlate with acceleration related indices. The reasons are discussed referring to the effect of the varieties of source characteristics on the ground-motion Fourier spectra from the discrete faults. The asperity location aspX negatively correlates with seismic intensities and with maximum structural responses because of the location between the reference site and faults. It is also detected that seismic intensities, M.S.I. and A_jma, can be better as hazard indices because the variations of structural responses along these indices are relatively smaller than those along other intensities.

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 Focusing on variation of peak period of horizontal to vertical spectral ratios (HVSRs) of microtremors due to time and space at flat engineering bedrock sites, we evaluate experimental variation coefficients and discuss the reason of the variation. The continuous microtremor measuments resulted in significant daily variation of peak periods of HVSRs, which are shorter in daytime of weekday than those in nighttime or weekend. Through a numerical simulation, it implies that the peak period are affected not only by subsurface structures but also by other factors such as the relative locations from stations to sources.

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 A parametric study is applied to determine the effects of rocking foundation input motion (RFIM) on the nonlinear behavior of SDOF elasto-plastic structure considering soil-structure interaction (SSI). A new lumped parameter model considering SSI is constructed based on the results of the thin layer method (TLM) for different embedment ratios of foundations taking place on homogeneous elastic half-space. After that the soil-structure model is analyzed under some earthquake records. Consequently, it is claimed that by increasing ductility factor values, the effect of RFIM becomes more important especially for high-rise buildings having deep embedment ratios. The reason of this phenomena is considered that equivalent elastic stiffness of superstructure becomes softer for increasing values of ductility capacity, therefore the additional force coming from the rocking input motion becomes more important than inertial interaction for the response of the superstructure.

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 This paper proposes design method for a hysteric dynamic absorber to reduce seismic response in super high-rise buildings. Friction, rigid-plastic and bi-linear hysteresis type are employed for the absorber. Optimal conditions for the initial stiffness, the post-yielding stiffness and the yielding strength of the damper are estimated by numerous time history analyses using an equivalent two degree of freedom systems. Finally, effectiveness of seismic mitigation for super high-rise buildings having wide variety of natural periods is confirmed through a comparison of a conventional linear viscous absorber.

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 Since it is well known that the vibration characteristics such as the eigenperiod and the damping ratio of buildings are dependent on the amplitude of vibration. In this paper, these characteristics of the horizontal first mode, based on the seismic observation records obtained from the low and middle raised RC and SRC buildings, are studied. These characteristics are evaluated corresponding to the 2 amplitude levels, the small earthquake level and the middle earthquake level. The observation data are analyzed using the ARX model. The effects of the experience of large earthquakes and aging for each amplitude level are investigated.

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 In this paper, the peak seismic response of an existing middle-rise steel reinforced concrete (SRC) building, which is composed both brittle and ductile members, is evaluated by the equivalent linearization technique and its accuracy is discussed. In this study, nonlinear time-history analyses of an example SRC building is carried out considering the strength degradation of shear-dominated brittle members, by using two groups of artificial ground motions; the phase angles are given by uniform random value and envelope function for the first group of ground motions, and for the another group their phase angles are given from records of the past earthquakes. The results show that the accuracy of the predicted peak response by the equivalent linearization technique is strongly depends on the phase characteristics of ground motions. To evaluate the difference of nonlinear response of an analyzed building, the substitute damping defined at peak response is calculated and compared to that defined at end.

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 This paper reports the scheme of a research project funded by the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) from the fiscal year of 2012 to 2014 under the title of “Development of base isolation device complied with the ultimate strength design code.” The theoretical prediction tells us a new approach to develop a highly stable laminated rubber bearing that has a constant buckling load even under large lateral displacement. Relatively high shear stiffness makes it more stable and the height of the bearing should be larger than its diameter. They are the newly discovered theoretical buckling stability criteria from the previous study that was conducted by the author's research team. The experimental study in this project shows the compatibility with the theoretical prediction and the highly linear load-displacement relationship under large deformation. The performance of the newly developed device satisfies the requirement of the ultimate strength design code, if the ground condition of the target building is normally solid enough to prevent liquefaction. The theoretically predicted buckling stability of the laminated rubber bearings has been actually verified by the specimens of this project.

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 This paper presents the horizontal soil resistance of pile group foundation by the static analyses using 3-dimensional nonlinear finite element method. Springs both at the pile head and around pile shaft are evaluated and discussed. The major findings obtained from this study are summarized as follows: 1) the horizontal soil resistance is different depending on the location of the pile. 2) soil spring around the pile at the edge of pile group is remarkably influenced by the direction of loading. 3) group-factor of soil spring around the pile is smaller than that of spring at the pile head. 4) when displacement of the pile becomes larger, the difference of soil spring at each pile becomes larger.

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 This paper presents an approximate evaluation method of foundation input motions (FIM) for adjacent embedded foundations on a premise that the impedance functions are known a priori. The method features distinctively in the point that the FIM can be readily evaluated only using ground motions observed in a free-field, once the impedance functions are obtained in advance. The applicability of the approximate method is examined analytically and numerically for adjacent semi-cylindrical foundations embedded in a homogeneous soil. A comparison of FIM evaluated by the approximate method with the exact result indicates a fairly good correspondence, and the availability of the presented method is confirmed.

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 The estimation of basemat uplift is an important factor for the seismic design of the nuclear power plant buildings. Nevertheless, the behavior is still not understood well, especially concerning to the vertical motion of the building due to the uplift behavior (the induced vertical motion). In this paper, the applicability of the soil FEM model in the low the contact ratio area is studied by comparing the impulsive Green function method. Next, using the model, the mechanism of the occurrence of the vertical induced motion is explained. Then, the simple method to estimate the outline value is proposed and the efficiency of the method is studied.

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 Damper distribution rule with equivalent linearization method on seismic control retrofit for overseas brittle RC buildings was proposed by the authors. However, this result is not necessarily proved as optimal. Recently, Genetic Algorithm (GA) is applied to solve numerous kinds of structural optimization problems, mainly in the range of static analysis. In this paper, the optimization method of damper distribution with GA using elasto-plastic dynamic analysis for multi degree of freedom shear spring model is proposed. By using proposed optimization method, the optimal damper distribution, defined as minimum damper distribution satisfying the target story drift angle for seismic retrofit, is obtained. Finally, comparison of the results with GA and solutions with equivalent linearization method is represented and the effectiveness of proposed damper distribution rule is discussed.

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 In this paper, a simple method for topology optimization of frame structures is proposed. In this method, ESO (Evolutionary Structural Optimization) method is applied to ground structure method. An exact optimal solution may not be obtained by ESO method because it is a heuristic method. However, the approximate solution useful for structural design can be obtained by this method. In the proposed method, the ground structure is generated by connecting all nodes by beam elements (but it is possible to limit the maximum length of the elements, and it is also possible to remove the unnecessary elements), and in the optimization process, the elements with the lowest strain energy are deleted based on ESO method. In order to demonstrate the effectiveness of the proposed method, in several numerical examples, the solutions obtained by the proposed method are compared with the solutions obtained by the density approach method (mathematical programming).

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 We have carried out a long-term measurement of prestressing force in permanent ground anchor which were employed to buildings. On the measurement results, we confirmed the time change properties of prestressing force and analyzed the quantity of each decrease by three known factors, relaxation of pulling materials, creep of the anchor fixation ground and subsidence right under the foundation which was tense and fixed ground anchors. Furthermore, we inspected the prediction method that was assumed at the time of the design, of prestressing force which was held 60 years later.

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 In this paper, the structural morphogenesis examples for free-surface grid shell with member of uniform length and joint angle are indicated. The building for a free-form surface grid shell structure of a magnificent and dynamic design became realizable from the confirmation of a structural rationality and the improvement of a construction technology. However, the constraint for a productivity and a workability of their structures produces in length of structural members and joint angle. In structural morphogenesis, it is important to use decent solutions that can be constructed with comparatively high evaluation including a global optimal solution (pareto optimal solutions), local optimal solutions (local pareto optimal solutions). The standard genetic algorithms (SGA) and strength pareto evolutionary algorithm 2 (SPEA2) are adopted with the structural optimization problem in order to obtain a global optimal solution and pareto optimal solutions, respectively. Genetic algorithms with immune system (ISGA) for a structural optimization procedure that implemented a manipulation of the decent solutions search is already applied to the structural morphogenesis for the grid shell.
 In the numerical examples, the decent solution forms of the analysis model for the symmetric grid shell structure on an in-plane rectangular geometry are shown. First, we indicate the geometric relationship and computational procedure for creating the free-form surface using the forward kinematics and inverse kinematics when the structural members are set to a uniform length and joint angle. Next, we apply this technique to the structural morphogenesis for a grid shell with the single- and multi-objective optimization problem. The objective functions are the total and the bending strain energy and the volume of interior space. Finally, the structural properties of decent solution forms obtained by ISGA are presented.

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 The present paper discusses the semi-active vibration control of double-layer cylindrical lattice shells with variable damping mechanisms. Some attempts to install the passive or active control devices to the lattice shell roofs are proposed for the purpose of controlling the seismic response of shell and spatial structures. Nowadays reserches of semi-active control is developed that produces any adjustable control forces by using variable damping mechanisms. However, there are few applications of this control method to the spatial strucutures. First, we attempt to apply the semi-active control method to a double-layer cylindrical lattice shell to reduce the seismic response. Second, the control effects are analysed and the results obtained by time history analysis are compared with of the passive and active control. Moreover, an arrangement method of variable dampers that considers the unique vibration characteristics of the lattice shells is proposed.

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 Shear wall tests of single CLT wall of which size is 1x3m were conducted to evaluate the shear performance and 4m width shear wall with opening tests consisting of double 1x3m of CLT panels and hanging panels were also conducted. Tensile bolts were used as connection between the shear wall and foundation, shear wall and hanging wall, and top-bottom of shear walls. Simple tensile tests for every bolt joint, compression, shear and bending tests for CLT panel were conducted to calculate the load-displacement relationship and to derive structural design procedure of the shear wall. As results of these static loading tests, the following conclusions are drawn;
 1. Each CLT panel remained elastic and shear deformation of CLT panel is less than the connections deformation. This highlighted seismic performance of CLT construction is controlled by the design and detailing of the connections.
 2. Equations to calculate load-displacement relationship of CLT shear walls are computed from the equilibrium of internal and external forces. The equations are validated with the experimental results.

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 Evaluate methods of short-term basic shear strength of a gable roof diaphragm in experiment and in calculation are inconsistent because these methods are assumed to be different yield mode. The evaluation method for shear performance of a gable roof diaphragm in the experimental procedure and in the calculation procedure with the assumption of same yielding mode is presented in this paper. When the maximum strength of a roof diaphragm is due to yielding nail joints between panel and rafter, short-term basic shear strength per unit length of a roof diaphragm is verified that well agrees regardless of pitch of roof and size by experiments and numerical analyses.

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 A model is presented for pushover analysis of reinforced concrete soft-first-story frames with columns extended toward inside of frames. The model includes a rotational spring of first-story column and that of beam. The beam spring represents the flexural resistance of the section which includes the beam and the second-story column. The yield deformation of each spring is determined based on the observed strain distribution of the longitudinal bars. The proposed model agreed with the test results much better than the conventional model, which provided up to twice of the observed strength and a half of the observed yield deformation.

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 Interactive behaviors of panel and joint at non-diaphragm CHS-column to H-beam connection were experimentally investigated. Herein, the panel indicates the cylindrical part surrounded by the outward forms of beam and column intersecting at right angles, and the joint indicates the seam between column surface and beam end. Two types of specimens were tested: one is an X-shaped frame in that the panel is subjected to shear resulting from a pair of anti-symmetric bending moments at beam ends, and the other is a 3-point bending specimen in that the panel is free from shear because of a pair of symmetric moments. It was found that the joint strength of non-diaphragm connection is little influenced by the shear in the panel, while its joint stiffness is significantly different between anti-symmetric and symmetric moments that is simply owing to the elastic action not to the panel shear.

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 The seismic response of rack warehouses is known to be reduced by horizontal sliding of the warehouse contents, which act as mass dampers. However, in past earthquakes business continuity has been interrupted due to damage from spilling, toppling or falling contents. In this paper, response control using seismic isolation is investigated. Because the total rack weight is constantly changing and the rack is often loaded at large eccentricities, Spherical Sliding Bearings (SSB) are proposed, which exhibit natural periods independent of the supported weight. Based on numerical and experimental test results undertaken previously, an analytical model is proposed including pressure and velocity dependent friction values. Using the proposed model, the performance of a seismically isolated rack warehouse with variable weight and eccentricity is studied and compared with conventional rubber bearings.

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 Design method of wood-concrete composite beams and experimental verification in the above paper were discussed as following items.
 1) Proposed solution to estimate deflection of beam:Assumptions for approximation; Kamiya's approximate procedure.
 2) Equation of approximate solution: Deflection of beam at loading point; Definition of symbols.
 3) Accuracy of approximation: Stiffness of shear connector; Estimated value; Shear modulus of timber.
 4) Design method for arrangement pattern of shear connectors: Estimation of deflection of beam.

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 The author thanks Satomi, SONODA for his discussion, and the answers are as follows;
 1. Proposed solution: Proposed method is different from Kamiya's procedure though it is based on his hypothesis.
 2. Equation of approximate solution: Deflection of loading point is mistake for the center of the span.
 3. Accuracy of approximation: Shear modulus of timber is not taken into account.
 4. Design method for arrangement pattern of shear connectors: Deflection error is on the side of prudence

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