It is not clear how much the blocking of coarse aggregate while passing between reinforcing bars and the settling of coarse aggregate during compaction with vibration are prevented in present concrete works. In case these types of segregation phenomenon occur, the distribution of ratio of coarse aggregate to matrix mortar becomes non-uniform in a concrete structure. In addition, it is considered that various properties of concrete also become non-uniform in a member due to this. However, the variation of these properties can not be observed from surface of members and is not recognized as the object of quality control and inspection.
 We consider that the method of mix design, construction, quality control and inspection to prevent the quality degradation of concrete in structures due to segregation need to be improved, in order to further upgrade concrete structures in the future.
 In this study, various types of concrete with different workability were placed into wall specimen with reinforcing bars to impede concrete flow, and the degree of segregation such as the blocking and the settling of coarse aggregate was examined. Furthermore, the effects of segregation on the distribution state of various properties of concrete in a structure were investigated. The following findings were obtained as the results.
 (1) Even if ordinary concrete has low segregation resistance, the ability that concrete can just pass between reinforcing bars does not always decreased.
 (2) In case ordinary concrete has low segregation resistance, the resistance to the blocking of coarse aggregate in concrete passing narrow space between reinforcing bars, whose clearance is approximately 35 to 40 mm or less, is significantly decreased. In addition, the resistance to settling of coarse aggregate is also decreased.
 (3) Even if the result of slump flow test does not shows the state of segregation, powder type and thickener type of high fluidity concrete do not always have enough resistance to the blocking of coarse aggregate while passing narrow space between reinforcing bars and to the settling of coarse aggregate.
 (4) The segregation between coarse aggregate and mortar makes much difference in amount of rise in temperature caused by heat of hydration, Young’s modulus and drying shrinkage strain of concrete in a member. By contrast, it makes little difference in compressive strength and surface quality.
 (5) The segregation state of coarse aggregate in concrete structures can be potentially grasped by non-destructive method such as the measurement of surface temperature distribution by infrared thermographic camera and the measurement of distribution of ultrasonic propagation velocity. Moreover, the on-peak surface temperature of concrete decreases averagely 0.14 °C and the ultrasonic propagation velocity increases averagely 0.020 km/s with 10 L/m³ increase of coarse aggregate content under the condition of this experiment.

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 The smoothness of the end surfaces of a concrete specimen is an important factor influencing the result of the compressive strength test, and there is a possibility that the apparent compressive strength changes greatly due to the smoothness of the end surfaces. Therefore, it is important to grasp stress distribution on the loading surfaces during compressive tests.
 Measurement of pressure distribution by pressure measuring films is performed by the color forming layer and the color developing layer in between the pressed part of the specimen and a loading plate. Color development is carried out by microcapsules of color forming layer when they are broken by the applied pressure, resulting in a chemical reaction in which a color former therein is adsorbed to the color developing layer. The film is considered guite useful to investigate and analyze the pressure and internal strains distribution in a hardened concrete.
 In this study, pressure distribution on the upper end surface at various stages of loading of normal strength concrete and longitudinal strain of the middle height of the specimen were measured by using the pressure measurement films and strain gauges, respectively. Experiments were carried out in two series. In Exp. 1, various end face treatment methods were applied to the upper part of a specimen, and in Exp. 2, a step was formed on the upper end face of the specimen. We examined the influence of these experimental factors on the compressive strength and strain.
 In addition, the reproducibility of the strain test results of the specimen by FEM (Finite Element Method) analysis using measured pressure distribution data was also examined.
 As for various end surface treatments, difference in pressure distribution was clearly observed according to the difference in the end surface treatment method, but it hardly affected the averaged strains of opposite side of a specimen.
 As for the specimens with the step gap on the upper end surface, it was found that the compressive strength was not greatly affected if the gap of step was within 0.1 mm, but was remarkably decreased when the gap exceeded 0.2 mm. There was no correlation between pressure distribution and strain distribution at the beginning of loading (stress stage of 5N/mm²). It is considered that the loading plate became oblique due to the step gap on the upper end surface, and the pressure applied to the specimen propagated diagonally.
 The main results in this paper are as follows:
 1) Although there are differences in loading pressure distribution due to differences in end face treatment methods, the average values and of the opposite side strains Young's moduli are guile similar regardless the treatment methods.
 2) By using the average value of the two opposite side strains, the influence of the step on the upper end face on the Young's modulus can be greatly reduced.
 3) In the FEM analysis using the measured pressure distribution, the influence of the pressure distribution on the upper end face of the specimen was largely reproduced, in the strain distribution.

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 Porous concrete (POC, no-fines concrete or pervious concrete), an environmentally friendly material, has received much attention in recent years due to its applications, such as permeable pavement, water purification site, being a vegetation base, or functioning as a habitat for organisms. POC is a special concrete consisting of a cementing matrix (paste or mortar), coarse aggregate, little or no fine aggregate, admixture, water, and continuous voids which are intentionally incorporated to produce various kinds of special characteristics. It has great potential to be used widely in both civil engineering and architecture in the future. Void ratio (percentage of voids), one of the most important properties, impacts various characteristics, such as strength, permeability, water retention, and water wicking. In addition, void ratio is easily changed and the void ratio of each part is likely to be different from that designed when constructed on site because of the variation of the degree of compaction and the wall effect of the mold where used. Therefore, the quality evaluation that directly evaluates the variation of the void ratio of each part of POC at post-construction is extremely important.
 According to previous researches, the ultrasonic wave velocity method is one of the simplest testing methods for POC. This is non-destructive and probably applicable to POC because there is a strong correlation between ultrasonic wave velocity and void ratio. Therefore, it is also considered possible to predict the void ratio of POC with ultrasonic wave velocity, if the relationship is expressed in advance by mathematical functions. Furthermore, it is possible to express and predict various characteristics of POC, such as strength, permeability, water retention, and water wicking, with the predicted void ratio.
 In this paper, relationships between void ratio and ultrasonic wave velocity of POC were examined. According to test results, it was confirmed that the relationship between void ratio and ultrasonic wave velocity can be fitted by a quadratic function. In addition, so as to clarify the main factor affecting relationships between void ratio and ultrasonic wave velocity of POC, cross-sections of POC specimens were analyzed. As a result of the analysis, it was confirmed that the minimum cost path through which ultrasonic waves propagate in POC is the dominant factor in the relationships between void ratio and ultrasonic wave velocity of POC.

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In this paper, cracks of concrete proceeded from corrosion of reinforcements are analyzed as indices of super long-term combined deterioration processes of RC building groups with finishing materials, pre-induced cracks and maintenance.
Specifications for finishing materials are systemized by permeability, deterioration mechanism, deterioration speed and demeanor after repairs and Agent Base Modelling is adopted about decision-making for building specifications.
It is clarified that the average acceleration period arrival rates vary in line with the characteristics of each scenario and are less than repair limits for the group and are one second of 3％ upper confidence limits.

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 A large number of super high-rise residential buildings have been constructed in Japan and quick damage evaluation is required after the future massive earthquake predicted in urbanized cities. In order to evaluate the general overview of nonlinear earthquake responses of super high-rise RC residential buildings, average models of nonlinear multi-degree-of-freedom system are constructed based on the structural characteristics of nonlinear earthquake response models used in the past structural design of the existing 39 buildings. By using the proposed average models, nonlinear earthquake responses of the eight super high-rise residential buildings in Kyushu Island during the 2016 Kumamoto earthquake are evaluated.
 The conclusions of this study are summarized as follows:
 1) The masses, linear and nonlinear springs per unit area are statistically compiled in terms of normalized height-wise distribution using the nonlinear earthquake response models. Bending shear springs used in some of the models are converted into equivalent shear springs. Modal participation factors from these models are also compared and their variation is found to be small. From above database, average models of nonlinear multi-degree-of-freedom system are proposed.
 2) Proposed average models of nonlinear multi-degree-of-freedom system are validated from the nonlinear response analyses using input earthquake motions for the structural design. Structural responses using these models are consistent with recorded motions obtained at plural super high-rise residential buildings in the Tokyo Metropolitan area during the 2011 Tohoku earthquake.
 3) For the nonlinear earthquake responses of the three super high-rise residential buildings in Kumamoto City, effects of the consecutive seismic input motions of the foreshock and the mainshock are investigated using strong motion records during the 2016 Kumamoto earthquake. The maximum inter-story drift angle is larger than that for only the mainshock, implying that effects of the foreshock were not ignorable.
 4) Maximum floor responses and inter-story drift angles of the proposed average system models were verified in comparison with those estimated from the results of questionnaire survey for residents in these buildings, e.g., scattering of small items on tables, action difficulty, overturning of furniture and cracks in wallpaper. Height-wise distribution is consistent between nonlinear responses and detected responses from the regression based on the 2011 Tohoku earthquake.

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 When extra-large earthquake which exceeds the input level of designing occurs, a base-isolated building may collide with surrounding retaining wall. To evaluate accurately the acceleration of superstructure and the deformation of base isolator at that time, restoring force characteristics of the retaining wall including the back soil should be clarified. In this study, the collision analyses of base-isolated building using 3D-FEM are carried out, and the restoring force characteristics of retaining wall are investigated. Simple modeling of the collision spring which have the initial rigidity and the maximum strength are proposed as for parameters of height and length of retaining wall, collision speed of building, collision height, and the shear wave velocity of back ground.
 The obtained results are summarized as follows.
 1) By collision analysis and evaluation of restoring force characteristics of a real base-isolated building model, retaining wall thickness, height and length greatly affect retaining wall restoring force characteristics. Initial stiffness and maximum load stress of retaining wall portion increase when the retaining wall thickness, height and length are increased. On the other hand, the weight of building and the ground at the bottom of the foundation board have little influence on the restoring force characteristic of retaining wall. In addition, the collision speed of the building exerts a large influence on the restoring force characteristic, and the initial stiffness increases as the collision speed increases, but when it reaches a certain collision speed or more, it reaches a certain limit and becomes constant. The maximum load increases with the square root of collision speed. Since the collision speed varies with the assumed input seismic motion, it is important to perform the earthquake response analysis on the building in advance and to use the speed at the time of displacement by the clearance between the building and the retaining wall. The initial stiffness and Maximum load increases as shear wave velocity increases.
 2) We propose Equation 7 for initial rigidity and Equation 8 for maximum load as a simplified retaining wall collision evaluation formula. By this formula, it is possible to install the collision phenomenon of the retaining wall of the base-isolated building in parallel with the spring of the base isolation device as a collision spring, by changing the shape (thickness, height, length) of the retaining wall and collision condition (Height, impact velocity), and the surrounding ground (shear wave velocity).

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 According to past surveys of pile-supported RC buildings, severe building damage was not reported so often although recorded seismic motions around the buildings were considerably larger than their seismic design motion. An effect of soil-pile-structure interaction is one of most possible reasons for this earthquake-damage reduction. However, actual shaking records at those buildings have been rarely obtained. Therefore, it is difficult to demonstrate actual phenomena with actual input motion and building records, and past research works were usually performed by numerical analyses under reasonably assumed conditions.
 In light of this, a dynamic experiment of a pile-supported RC structure was conducted using E-Defense shaking table to obtain series of data, which are expected to help understanding its failure process. The structure model was three-story RC frame supported by PC piles. The model was built in a RC container filled with dry sand, and the PC piles were embedded in the sand. The model was built in a scale of 1:2.5. Long spanned two steel beams were installed on footings of the RC structure to prevent the model from falling in case when significant damage of the piles induced considerable loss of their axial load capacity. An acceleration wave of input motion was evaluated based on an attenuation relationship of response spectra.
 Prior to the shaking table test, a static loading test of a footing supported by four PC piles in dry sand was conducted to make a plan of the dynamic test model. From this static loading test of the footing, the strength and deformation capacity of the soil-pile interaction system were obtained. Dynamic response analyses were conducted using a frame model with a nonlinear sway spring assumed by this static test. Based on the results from the above analyses, an excitation plan of shaking table was scheduled from 10% to 300% or 400% of the designed acceleration motion.
 The shaking table tests were started from 20% level showing linear response characteristics and finished at the level of 300% with fatal failure of the pile heads. In the case of 200% input, no sign of structural failure such as subsidence or tilting of the frame appeared. On the other hand, strains of PC steel bars in the PC piles exceeded yielding strain, and compression strain of their surface concrete also exceeded failure strain. This means a field investigation only on damage of superstructures after earthquake might miss a finding of pile damage.
 In the case of 300% input, the strength deterioration and then the loss of axial load capacity of the piles were recorded at the pile head displacement expected by the above dynamic response analyses. Thus, it was shown that the preliminary analyses of the dynamic tests had given reasonable behaviors of the test model. In this input, the pile heads finally reached compression failure, and such damage corresponded to the actual failure. On the other hand, damage of the superstructure were slight. This result suggests the possibility that the damage of the superstructure was suppressed by nonlinear behaviors of the soil-pile system.
 Through the shaking table tests, series of data were obtained from small input tests where both a structure and piles were undamaged and large input tests where pile heads were damaged like actual pile damage in past large earthquakes.

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 Rotating inertial mass dampers were developed as a vibration control device and have been applied to actual buildings in recent years. An inertial mass damper is able to generate an inertial force of thousands of times of their mass weight by the inertial mass effect determined by the diameter of the flywheel and the lead of the ball screw. The damper then reduces an earthquake response owing to the inertial force acted on the structure.
 In this paper, we conducted full-scale vibration tests on three types of inertial mass dampers with inertial masses of 2,500 ton, 4,000 ton, and 6, 500 ton, and clarified the mechanical characteristics of the dampers in the temperature range from 0 °C to 40 °C. We proposed a dynamic model of the damper that is able to express the vibration test results and verified its validity. The proposed dynamic model considers the inertial mass, the viscous damping force and the friction force of the damper as mechanical characteristics. We examined the variation of the mechanical characteristics and the durability of the damper by repeated vibration tests. The inertial mass damper has an overload prevention mechanism to avoid excessive reaction forces. In the test, we have targeted the range which the overload prevention mechanism operates (relief) and large displacement occurs in the damper. The obtained results are as follows;
 (1) The generated inertial mass is found to be almost constant irrespective of the vibration frequency, the amplitude and the temperature. The frictional force depends on the temperature, and increases as the temperature decreases. The viscous damping force depends on the temperature and the vibration frequency. We proposed the correction formula that is able to estimate the viscous damping coefficient at given temperature and excitation frequency.
 (2) The slope of the force-displacement relationship after the relief mechanism operates corresponds with the inertial mass of the ball nut. The maximum load increases in both the compression side and the tensile side due to the difference between the static friction and the dynamic friction in the relief mechanism. The burden on the tensile side is larger than that on the compression side.
 (3) Repeated vibration tests were carried out until the cumulative rolling distance reaches 100 m, and no change in the mechanical characteristics was observed.
 (4) We developed a structural analysis model of the damper that comprises the inertial mass element, the viscous damping element, the friction element connected in parallel. The relief mechanism was modeled as a friction element that takes into consideration the difference between the dynamic friction and the static friction and the asymmetry of the positive and negative loads. The proposed model is able to accurately express the hysteresis characteristics obtained by the experiments.

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 The authors have been developing a new seismic isolation bearing, which consists of a lead rubber bearing (LRB) and a slider bearing as a fail-safe (FS) mechanism in series. The bearing called “FSLRB” behaves as a general LRB which is just friction connected to the building structure at either of upper or lower end, when subjected to design level earthquakes or smaller, while the sliding behavior keeps LRB away from giving excessive hardening and shear break in severe earthquakes beyond expectations. Hence, FSLRB has much higher seismic safety compared to general isolation bearings including conventional LRBs. In this paper, dynamic and quasi-static horizontal loading tests under constant or varying compressive loadings for several kinds of scaled and full-scale FSLRB specimens are conducted, to evaluate the effect of bi-directional excitations on additional torsion in the LRB part and changes in friction properties in the slider part. Ultimate performance limit of a full-scale bearing is also investigated under extremely high surface pressures beyond expectations.
 Dynamic loading tests of two types of □-200mm scaled specimens, each has different second shape factor in the LRB part, make clear that there is no apparent difference in friction properties between uni-directional and bi-directional excitations, and no damage to the LRB part due to the torsional behavior in bi-directional excitation, as far as the bearing is applied under a reasonable surface pressure around 10 N/mm². Bi-directional dynamic loading tests of a □-900mm full-scale specimen show that there is no significant scale-effect between the full-scale FSLRB and the □-200mm scaled one on both the torsional behavior of the LRB part and friction properties of the slider part. Uni-directional dynamic loading tests of □-600mm full-scale specimens indicate that dynamic and static friction coefficients have quite low velocity dependence in reasonable sliding speed expected in the practical use. Finally, uni-directional quasi-static loading tests of □-600mm specimens show that the bearing should be applied under surface pressure of 20 N/mm² or lower, to give a well-ordered tri-linear hysteresis curve without causing any unexpected incidents such as partial uplift of the slider part and buckling or shear break of the LRB part.
 Furthermore, surface pressure dependence of dynamic and static friction coefficients are inductively estimated applying all the data obtained in the series of the research, including the test results of □-60mm scaled slider, □-414mm scaled FSLRB and □-900mm full-scale FSLRB introduced in the authors’ preceding paper. The data indicate that both dynamic and static friction coefficients are highly affected by the dimensions of each FSLRB, those are the second shape factor of the LRB part and out-of-plane stiffness of the steel plates between the LRB part and the slider part. By introducing “effective surface pressure” reflecting the effect of the above two dimensions, friction coefficients can be even accurately estimated compared to a conventional method only using mean surface pressure.
 As a conclusion through the series of the loading tests and the considerations mentioned above, the authors think that FSLRB is ready for the practical use in a seismic isolation system with even higher safety margin compared to conventional systems.

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 Simulation analysis is an effective method for the safety assessment of a building after an earthquake. This kind of analysis is effective for evaluating foundations or piles, whose safety cannot be confirmed by visual check.
 In conducting these analyses, an input motion should be set to reproduce an observed wave at an observed point of the analysis model. If the analysis model is in a linear range, the input motion can easily be set using the frequency domain method, which is the most popular method. However, this setting is difficult if the analysis model (e.g., soil) exhibits non-linear behavior. In these cases, the properties of the analysis model changes at every time step. Therefore, the frequency domain method cannot be applied. Instead, the time domain method must be applied, but no effective inversion method of the time domain is available.
 This study proposes a new time domain inversion method. First, the method outline and details are described. Second, the method precision is confirmed through experimentation. Thus, a new method for an input motion inversion in a non-linear soil model is presented.

 Followings are a summary of the study findings:
 (1) This study proposes a new time domain inversion method with a generalized inverse of the perturbation impulse matrix and the iterative method. In proposed method, first, effects of perturbation impulse inputs are calculated. Secondly, “perturbation impulse matrix” is made from these effect vectors. Then, from singular value decomposition of perturbation impulse matrix, general inverse of the perturbation impulse matrix composed by main modes is made. Using this inverse, input correction amount is calculated. And then these corrections repeated until error become small enough.

 (2) Through a sample problem, the accuracy of this proposed method is confirmed. Then, it is confirmed that an identified input motion reproduce a target output motion in surface of elasto-plastic soil model.

 The findings of this study confirm the applicability of this proposed method for inversion. There is, however, the need for further improvement of the procedure because it is difficult to select effective modes. Moreover, much calculation time that this method need is important an important issue.

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 In Japan, domestic timber has about 50% of for post and sill, but has only 9% for beam or joist. MOE of Japanese cedar, the representative species of domesbtic timber, is lower than imported timber. (MOE of Japanese cedar is from 5 to 8GPa.) The cross-sectional size of floor beam is almost determined depend on bending deflection in practical design. Since using domestic timber for beam makes a result of increasing timber volume and spending much money, it is considered not to be used (or not to be produced). If the cost problem would be solved, there is possibility to increase demand of domestic timber for beam. We think use of higher efficiency of cross section, and aim at developing I-beam what is suitable for conventional structure in Japan. The goal of developing is to save 50% of timber volume for floor beam.
 Upon selecting the main material, the web had a few options. It was determined by checking the shear property in the preliminary test, considering the connecting method and other factors. Structural test of the beam, durability test and long-term performance test are included in the procedure for developing I-beam, and finally design method for I-beam has been proposed.
 I-joist products in US and Canada often has OSB for web. Because OSB has excellent shear property, and cost is also cheap. But there is no OSB made from domestic tree species, and also no OSB factory in Japan. Finally, plywood and Diagonal Lattice Panel (DLP) become options for web. DLP is a diagonal grid lattice panel (thickness: 18mm), that has 2ply of 45 degree diagonal laminas arranged at grid interval of 151mm. Cross-section size of the lamina is 55mm wide × 9mm thick, and those are bonded each other by using API adhesive.
 Two Rail Shear Tests were carried out for finding out appropriate material from plywood and DLP. The results shows DLP has excellent shear property. Modulus of shear stiffness for DLP is about 2.2 times of that of Plywood, and 0.85 times of OSB. Comparing shear strength with OSB, average shear strength of OSB is 8.44MPa, that is 2 times of DLP. However, if simply compared as a single panel, since DLP (18mm thick) has twice thickness of OSB (9.5mm thick), Shear capacity is nearly equal and shear stiffness is 1.6 times of OSB. Two of them are almost same timber volume. DLP has goodness that pipes can pass through easily like water supply or cable ducts. We decided to use DLP for I-beam web, because of these advantages.
 Designed I-beam has LVL flanges using Japanese larch and web of DLP. The flanges and the web are connected using tongue and groove joint of two rows with resorcinol adhesives. Beam tests were carried out, that include bending and shear test in some kind of different loading. These tests results established design strength and stiffness.
 Shear strength decreasing was observed in the tests depend on shear zone length, length effect in shear was found. In order to study whether the length effect can be explained by the weakest link theory, we tried to predict another test value from the cumulative distribution function of strength given by Weibull distribution from observed shear test data. The deviation between the experimental strength and the predicted strength was so large that there might be something affecting length effect beside the weakest link theory. Effective second moment of area of section, effective modulus of section, shear stress coefficient in cross section were calculated by the equivalent homogeneous cross section method. These structural property for design and beam design method were proposed.

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 1. Introduction
 This paper describes investigation about hysteretic restoring force characteristics of reinforced concrete wall column specimens. Static loading tests of three specimens were conducted. Nonlinear finite element analysis were conducted for three specimens. The objective in this paper is to investigate effect of bond behavior of post-installed adhesive anchors on restoring force characteristics.
 2. Outline of the Static Loading Tests
 Three specimens were tested. One of them, WS485, was ordinal reinforced concrete specimen, while in the other specimens, post-installed adhesive anchors were used for main bar anchorages. The difference between the other two specimens was anchor length of main bars. One of them, the specimen named as WA485 had the same length as the RC specimen WS485. The other post-installed adhesive anchor specimen, named as WA265 had shorter length of anchorage than the other two specimens. As the test results, yielding of the main bars were observed for all specimens and three specimens had almost same capacities. Slip behaviors were observed in WA265 and WS485, and energy dissipation capacity of specimen WA265 was lower than those of the other specimens.
 3. Modeling for Nonlinear Finite Element Analysis
 Three-dimensional nonlinear finite element analyses were conducted using “FINAL”. Concrete was modelled using eight-node hexahedral element and main bar was modelled using truss element. Four-node joint type elements were inserted between hexahedral elements and truss elements of main bars for the purpose of incorporating bond slip behavior. For the specimens WA485 and WA265, the perimeter length of post-installed adhesive anchor was calculated from the diameter of drill instead of main bar.
 4. Comparisons of Analytical and Experimental Results
 Crack patterns were shown in Figure 5, and load-displacement relationships were compared in Figure 6. Horizontal cracks along the main bars in stub were observed in both experimental and analytical results. Slip behavior in load-displacement relationship for the specimen WA265 and WS485 obtained from the analyses were observed similar to the experimental results. Although the equivalent viscous damping ratios of analytical results for specimen WS485 and WA485 were slightly underestimated to the experimental results, analytical results for the specimen WA265 showed good accordance with experimental ones. Load and flexural, or shear, displacement relations were shown in Figure 11. Fig. 11 shows that the slip behavior was observed in flexural mode. Figure 12 shows the stress distribution of main bars for both analytical and experimental results. Although the analytical results in tension corresponded well to the experimental ones, analyses underestimated in compression.
 5. Conclusion
 Restoring force characteristics of RC wall column specimens were investigated both experimentally and analytically. Three types of main bar anchorage were investigated. One was ordinal type, while the other two were post-installed adhesive anchors. Anchor length was varied in the latter two specimens. The specimen WA265, which had shorter length anchorage showed lower energy dissipation characteristics than the other two specimens and slip behavior was observed. Analytically, these behaviors were shown with good accordance with the experimental results. Stress distribution of main bars derived from analytical results corresponded well to the experimental ones only in tension.
 Acknowledgement
 Static loading tests were conducted through the project: “study on confirmation methods of structural performances for RC members using post-installed adhesive anchors”, which was supported by the subsidies for the project servicing the architectural standard from the Ministry of Land, Infrastructure, Transport and Tourist.

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 Cold-formed steel members are widely applied in low-rise residential houses. One of the key issues in their design is the local buckling strength under compression. It is well known that the local buckling strength of a plate element is affected by its boundary condition and the section shape significantly affects its maximum strength. Moreover, the design provisions usually assume that the plate elements, which comprise a cold-formed steel members section, behave like a simply supported plate and do not consider the restraining effect between adjacent plate elements. In this paper, we focused on the restraining effect between adjacent plate elements and investigated their elastic and inelastic local buckling strength by finite strip analysis and finite element analysis.
 First, we investigated the elastic local buckling strength and maximum strength of rectangular sections by numerical analysis; finite strip analysis and finite elements analysis. Through these numerical analysis, we found that the local buckling strength of long side plate element, which comprise the rectangular section, shows higher strength than that of simply supported plate elements under axial compression. This strength increase is caused by the restraining effect between adjacent plate elements; the rotation at longitudinal edges of long side plate was restrained by short side plate elements.
 Then, based on the energy method, a semi-theoretical equation for the elastic local buckling strength on a restrained plate element was derived, which assume that the deflection of a restrained plate element whose longitudinal edges are elastically restrained can approximate the linear sum of the displacement function of simply supported plate element and that of the fixed plate element. The suggested equation agreed well with the elastic local buckling strength of rectangular sections obtained by eigenvalue analysis.
 Finally, we evaluated the maximum strength and inelastic buckling strength of rectangular section members and lipped C section members by the developed equation; which can evaluate the elastic local buckling strength of restrained plate elements. Through the comparison between the nominal strength which consider the restraining effect and that ignore the restraining, it was found that the variation of nominal strength with respect to the maximum strength could be decrease considering the restraining effect between adjacent plate elements.

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 The stiffening effect on the lateral buckling caused by attaching a restraint member such as slab and purlin members to an upper flange of an H-shaped beam is widely known. This stiffening effect occurs not only when the upper flange is the compression side but also when the upper flange is the tensile side, even though to a smaller extent. Considering that the floor slab is attached to the upper flange, the restraint conditions can be considered close to completely restrained. However, depending on the combination between the floor slab and beam cross-section, the upper flange restraint conditions cannot be considered completely restrained.
 In this study, first, we conducted a comparative analysis between a model that the rotational restraint of the slab is caused by bending resistance and another model that it is caused by torsional resistance, followed by an analysis considering the effect of both. Then, we considered that the rotational restraint is caused by the bending resistance alone and determined how the dimension of rotational restraint influences the buckling strength by conducting a theoretical analysis based on an energy method. When doing so, we summarized it by using a cross-sectional shape index and clarified the relationship between strength increase due to restraint and cross-sectional shape. We also proposed a method to calculate the elastic lateral buckling strength that considers the dimension of the restraint. In addition, we expressed the conditions to achieve complete restraint in terms of the bending stiffness ratio of the slab and web and compared with a realistic bending stiffness ratio of the slab and web. Lastly, we conducted a FEM analysis to determine the stiffening forces that occur in the upper flange.
 As a result, the following conclusions were obtained: 1) We verified that when the restraint effect caused by both the bending and torsion resistances of the slab is considered, achieving complete restraint is easy compared with when these are considered individually. However, the results also showed no significant difference when either of them was considered individually. 2) The strength increase caused by the horizontal displacement complete restraint alone can be explained by the cross-sectional shape index R. The strength increases caused by the effect of both the horizontal displacement complete restraint and rotational restraint can be explained by the cross-sectional shape index T_S. 3) The decrease rate d of the elastic buckling strength can be explained based on the dimension of the rotational restraint and T_S. The elastic lateral buckling strength that considers the dimension of the restraint can be calculated using the elastic lateral buckling strength of complete restraint and the decrease rate d. Using the proposed elastic buckling strength, it is possible to evaluate the plastic deformation capacity using a method similar to that of complete restraint. 4) When relying on the bending resistance of the slab, if the bending rigidity ratio of the slab to beam is 10 or higher, it is possible to secure a strength of 95% of the elastic lateral buckling of complete restraint. By using cross-sections with a narrow and medium width as established by JIS and with constant external dimensions, this condition is satisfied in around 75% when the slab thickness is 150mm; this condition is satisfied for almost all when the slab thickness is 200mm. 5) Until the plastic deformation capacity of a beam is satisfied, the dimension of the stiffening force that occur in the upper flange has a correlation with the plastic deformation capacity, and therefore, it can be explained using a general slenderness ratio. Further, the maximum value of the stiffening force can be evaluated using a simple approximate equation.

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 An Autoclaved aerated concrete (AAC) is an efficient structural material because its light weight reduces seismic inertia forces under earthquake excitations and improves thermal insulation quality for comfortable environments. Since an AAC panel structure can't be designed in Japan, we propose a reinforced and fully grouted AAC block masonry structure. Few experimental studies of bearing wall constructed of non-reinforced AAC blocks are available. In this study, in-plane tests of bearing walls constructed of reinforced AAC blocks with internal bars and the non-reinforced AAC blocks were carried out and the effect of the internal bars is confirmed. Furthermore, the strength and deformation calculated referring to previous studies in concrete block masonry structures were compared with test results.
 Three types of AAC blocks (ALC50, ALC37 and ALC42) which have different specific gravity and the internal bars or not constitutes the masonry wall. ALC50 and ALC37 have the internal bars and ALC42 doesn't have them. Each AAC block has grooves and vertical holes. Vertical reinforcements are cast in the holes and horizontal re-bars are cast in the grooves. After the blocks are pasted with sealant and built, the grooves and holes were fully grouted in order to achieve a good bonding behavior between the reinforcements and the blocks. Each mechanical property of the materials is shown in Table 2.
 Compression and shear wallette tests were carried out and those mechanical properties and those failure behaviors were obtained. The test specimens with the internal bars avoided the sharp post-peak drop and enhanced displacement capacity. Therefore, it is considered that the internal bars provide confinement under the compressive force and shear reinforcing effect under the shear force.
 In-plane tests of masonry bearing walls without openings were carried out. A suite of five specimens which have different block type and wall length (aspect ratio of 0.7 to 3) was tested by using a test setup of cantilever system. In the test results, a bed joint separation, a flexural crack, a shear crack and yielding of vertical bar were confirmed and integrated wall behaviors were observed until peak load. Flexural failure mode or shear failure mode after yielding was observed. The shear failure mode after yielding was observed in the specimen of few horizontal reinforcing bars or low aspect ratio or built with the non-reinforced blocks.
 Based on the mechanical properties obtained from compression and shear wallette tests, strength and deformation were calculated referring to previous studies in masonry structures. The flexural strength and the flexural deformation were calculated with the equation of simple bending theory. The shear strength was calculated with equation of concrete block masonry structures and the shear deformation was calculated with equation of theory of elasticity. The calculation results of the strength are almost good agreement with the test results. The calculation results of the deformation are a little lower than the test results because an effect of shear crack for shear deformation was not considered
 In the case of structural design for this AAC masonry structure, we propose to take into more consideration for safety because of a limited number of experimental tests in this study.

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