Various air-permeability tests have been studied as a method for evaluating quality of cover concrete using non/ minor destructive methods. In particular, the double-chamber method is often applied to evaluate the quality of cover concrete for civil-engineering structures. Regarding the double-chamber method, although evaluation is currently performed based on the Swiss standard, evaluation criteria which is suitable to Japanese construction site is not well developed.
 Hence, as a first step towards the final purpose described above, this paper deals with round-robin test study in order to reasonably evaluate the quality of cover concrete by the air permeability test. The round-robin tests were carried out using eight double chamber method(DC(TPT)) machines, two types of single chamber method(SCM) and three types of drill hall method(FIM).
 From experimental results, authors investigated coefficient of variation of the air permeability indexes due to the difference in the testing machine and the difference in the quality of the cover concrete. In addition, authors investigated the correlation between each test results and the results of RILEM CEMBUREAU method which is benchmark test of air permeability test.
 The following conclusions were obtained through the round robin test for various air permeability tests.
 1. The permeability coefficient K by the RILEM method accurately evaluated the quality of concrete of the actual wall for each nominal strength. The DC (TPT) method and the FIM method were highly correlated with the RILEM method which was a benchmark test, and the FIM method had a very high correlation with the DC (TPT) method.
 2. The variation coefficient of the kT in the DC (TPT) machine was 25% due to only the difference of the test machine, and the variation coefficient when averaging the measured values of 6 points on the concrete wall was 65%. As a result, the variation coefficient of the kT due to the difference in the quality of the cover concrete was about 40%, which value was close to the coefficient of variation of the neutralization depth of existing RC structures.
 3. The variation coefficient of the P.V. in the FIM method was about 35%, which roughly agreed with the coefficient of variation due to the difference in the quality of the cover concrete by the DC (TPT) method.
 4. The average value of the kT measured at 6 points from the same concrete wall by the DC (TPT) method had high correlation with compressive strength. In addition, the FIM method had an extremely high correlation with the compressive strength compared with the SCM method, and the change in the P.V. due to the change in compressive strength were larger than that of the A.P.I..

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 It is significant to accurately evaluate how a building is damaged soon after a seismic event from the building use continuation judgement point of view. As an effective tool for such a judgement, structural health monitoring (SHM) schemes have appealed the attentions of structural engineers. In conducting SHM for a building structure, it would be desirable to install sensors into all the stories. At the present stage, however, such a sensor installation scheme would be expensive, and thus it would be realistic to construct the SHM strategy based on the use of a limited number of sensors. From the point of view of what kind of responses are appropriate for effective SHM, on the other hand, inter story drift deformation could be a powerful index. The second authors' research group has developed a direct measurement devise sensing drift displacements. Accounting for the fact that accelerometers have been much more practically utilized, this paper proposes a methodology which would estimate the drift deformations for all the stories with accelerometer implementation on a limited number of floors.
 The beneficial point of the proposed method is to derive all of the necessary information with respect to a building from the measured response data. In other word, the estimation of all the stories' responses is conducted based on only the accelerometer data. The method proposed in this paper utilizes cubic spline interpolation (CSI). In applying CSI to building's response interpolation, how to set the end conditions at the top floor and base floor locations is very significant. This paper proposes how those end conditions should be set. As the boundary condition with respect to the building top floor vicinity, the location over the top floor at which the first derivative of the response distribution is always zero is introduced. This location is to be determined from the first mode shape of a building. As above-mentioned, however, this method does not use other information than the measured acceleration data. The first mode shape is derived from the acceleration responses. For the boundary condition at the base floor location, the degree of fixation at the base floor is accounted for. The semi-fixed boundary condition is introduced by mixing the fixed and pin base conditions. The mixing ratio of these two is also determined from the derived first mode shape. Employing the two newly-employed boundary conditions, all the story responses are estimated accurately.
 The validity of the proposed method is demonstrated by using the experimental data from the E-Defense shake table tests of a 1/3 scale model steel building with eighteen stories in December 2013. In this experiment, the model building was repeatedly shaken with simulated long-period ground motions with different magnitudes. The ground motion became larger and larger until the model building was collapsed. Employing the data measured by five accelerometers set on the first, second, seventh, thirteenth and roof top floors for some cases of the experiment, the paper demonstrates how accurately the acceleration response time histories of all the stories are estimated and then the drift deformation time histories are estimated.
 The interpolation method proposed in this paper provides an accurate estimation of all the story responses. It would lead to an accurate judgement framework of story-based damage states only with the installation of a limited number of sensor and without any of pre-information on the motion characteristics of a building, such as mode shape function.

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 We have reported an active seismic response control system by making use of an energy conversion in damping devices. This system converts the vibration energy of the structure by large earthquakes with a damper, and accumulates it. Then, it reutilizes this energy, and drives an actuator as a vibration control device. In this paper, we propose a numerical analytical method considering the dynamic characteristics of hydraulic technology which can control large forces and energies easily. Various system characteristics are evaluated using this method, and the following knowledges are summarized.
 (1)Various energy characteristics including the input-and-output energy balance and the maximum responses of vibration models of active and passive seismic control are expressed through the numerical analyses reflecting the energy characteristics based on hydraulic analyses.
 (2)The pressure control mechanism of accumulators corresponding to the earthquakes level is proposed. Through the analyses for the parameters of the earthquake levels and the accumulator pressures, it is inspected that the input-and-output energy balance can be kept well by changing the accumulator pressure which corresponds to earthquake levels.
 (3)The switching technique of the active and the semi-active damping based on the time history characteristics is proposed to improve the input-and-output energy balance. Through the numerical analytical method using proposed technique, it is inspected to maintain the maximum response values equivalent to the active seismic response control, while keeping the input-and-output energy balance well.
 We have shown that the characteristic evaluation of the system is possible by the simple numerical modelling where the dynamic characteristics of the hydraulic mechanism can be expressed without the complicated hydraulic pressure analyses. In addition, two methods improving the input-and-output energy balance are proposed and its validity is inspected.
 Furthermore, we have clarified the need considering the energy conversion efficiency of the actuator by proposed numerical analysis models.

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 This study concerns an analytical method to investigate the dynamic characteristics of a Linked Fluid Inertia Mass Damper (LFIMD). The damper consists of two cylinders, piston rods, and link tubes. Two piston rods are linked and move following the oil flow in the link tubes connecting two oil chambers. It can change the stroke ratio of the two piston rods to arbitrary values by adjusting the cross-sectional area of the linked oil chamber. In this study, we use a hydraulic link mechanism as a story deflection control system. This mechanism can adjust the story deflection ratio when installed across the upper and lower stories.
 In the first part, we study the influence of the link stiffness on the dynamic characteristics of a two-story structure. First, we show that the eigenvectors converge to arbitrary values by installing a link mechanism with sufficiently large link stiffness. In addition, the link mechanism does not change the natural period in the 1st mode regardless of link stiffness, but the second mode natural period becomes shorter. Therefore, in the case of the link stiffness is sufficiently high and the story deflection is linked, we can calculate the response of the entire structural system without considering the influence of the 2nd mode. Next, we derive the theoretical solution for harmonic oscillation. The theoretical solution shows that the dynamic characteristics of the link mechanism depends on the apparent total stiffness that is different from the real stiffness of the main structure. Moreover, the apparent stiffness of the story changes when the piston displacement ratio of the linked damper is changed. The apparent stiffness exhibited by the linked damper is the opposite sign and same absolute value in the upper and lower stories. The additional stiffness of the link mechanism is determined based on the transfer relationship of the shear forces between the linked stories, and we call it the redistribution of shear forces by link mechanism. Basically, the link mechanism redistributes the shear force from the relatively strong layer to relatively weak layer, resulting in the link mechanism adding the apparent positive stiffness to the weak layer and the negative stiffness to the strong layer. By organizing the theoretical solution and the generalized eigenvalue program, if the eigenvalues of the original structure are known, it is possible to estimate the redistribution of shear forces without any time history response analyses.
 Finally, we conducted shaking table test using specimens with different stiffness distributions along the upper and lower stories. We used two models; the first one has nearly uniform deflection in each story (Specimen A), the second one is so designed as to show deflection concentration the lower story (Specimen B). From the redistribution method for shear forces, it was predicted that the redistribution of shear forces in specimen A was small, and the shear forces were redistributed from upper layer to lower layer in specimen B. The test results showed that the story deflection was as expected in the case of the specimen without the damper and that it is quite easy to make the story deflection uniform by using the link mechanism. Next, we evaluated the apparent stiffness, apart from the effects of the inertia mass and the link mechanism, exerted by the damper, using a dynamic model constructed based on experimental results. It is shown that the negative stiffness by inertia mass effect is constant regardless of the stiffness distribution, and that the positive or negative stiffness by link mechanism is relatively high and dominant. We confirmed the validity of the theoretical assumed dynamic characteristics of the link mechanism.

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 Floor response spectrum is useful information in seismic design of nonstructural components such as ceiling and equipment. Its spectral peak, which occurs in resonance, is important in terms of deciding seismic design force of nonstructural components. The peak acceleration normalized by floor acceleration, which is independent of seismic intensity is called dynamic amplification ratio (DAR). The magnitude of DAR is affected by damping ratios of building and nonstructural component. In addition, it is empirically known that the DAR decrease as natural period of nonstructural component is longer, or duration of ground motion is shorter. However, this tendency has not been well clarified. The objective of this paper is to investigate the effect of duration on DAR and propose a closed form of expected DAF denoted by the characteristics of both the system and ground motion.
 Both buildings and nonstructural component are modeled as an elastic single degree of freedom (SDOF) system, respectively. Firstly, two idealized excitation are considered to obtain upper bound and lower bound of DAR. One is a stationary response to white noise excitation, which give an upper bound of DAR. Another is a response to white noise with infinitesimal duration, which gives a lower bound. The latter corresponds to response to impulse input. Based on convolutional integral, a closed formula is derived for these conditions.
 Subsequently, DAR is discussed in case of excitation with finite duration. Equivalent number of cycles for building response is introduced. The number of cycles is defined by ratio of the duration of ground motion to natural period. This value is incorporated with geometric mean of two damping ratio of system. The proposed variable give a degree of acceleration development associated with lapse of time. Stochastic time history analysis is conducted to verify the non-dimensional variable. It is clarified that this variable comprehensively explains the effect of short excitation on decrease of DAR.
 Next, effectiveness of the explanatory variable is shown for historical earthquakes. A total of 1, 684 historical records are selected from the PEER ground motion database. The DARs calculated by time history analysis are normalized with the predetermined lower and upper bounds previously discussed. As a result, the DARs are mapped into a space with numeric between 0 and 1. Statistical relationship between the mapped DAR and the explanatory variable approximately trace a single curve for wide variety of structural characteristics and earthquakes. In order to express this curve, a regression formula is proposed for practical engineering. The proposed formula has four variables including natural period, two damping ratio, and significant duration of ground motion.
 Finally, it is confirmed that the DARs evaluated from the formula are in good agreement with expected DARs. The formula also implies that DAR dramatically decreases over certain threshold period.

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Natural period and damping ratio are important values in seismic design. Recently, many of the findings for these values have been obtained from earthquake observation records. However, the observation records of buildings are affected by the soil–structure interaction. Therefore, only the characteristics of the building structure are unclear. This study focused on the structural vibration characteristics by using the records of large shaking table tests. Steel specimens subjected to strong input motion were studied, and the experimental data were analyzed using the ARX model. Moreover, the effects of the experienced largest deformation on the vibration characteristics were investigated.

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 In recent years, timber structures are popularly applied for lattice shell roofs to create a long span space due to lightweight and aesthetics. This research proposes several types of steel connections for timber lattice shells improving structural performance and architectural appearance. The out-of-plane flexural strength and rotational stiffness of the proposed connections are examined by full-scale experiments. Based on the experimental results, the seismic performance of timber lattice shell roofs using proposed connections is investigated.
 Dimensions of a single-layer timber lattice shell are assumed to be 24 m × 24 m × 3.2 m. The five types of connections are proposed for this single layer lattice shell as shown in Fig. 2. Rectangular laminated timber members are fixed to tee or wide flange section with lag screws. These connections basically resist to out-of-plane bending moment by the pull-out force of lag screws and bearing force between the timber members and steel connections as shown in Fig. 3. Tests on three specimens for each type of connection were carried out to confirm the rotational stiffness, flexural strength and fracture mode with respect to out-of-plane bending.
 Numerical simulations of a single-layered timber lattice shells illustrated in Figs. 7 and 8 using proposed five types of connections were conducted to investigate their buckling loads. The strength reduction factor for elastic buckling load against linear buckling load α₀ was estimated approximately as 0.9. Fig. 10 shows that the strength reduction factor due to connection stiffness β(κ), stipulated in AIJ Recommendation for Design of Latticed Shell Roof Structures (AIJ Rec for Shell), and found to be less than the calculated values in numerical simulations with evaluated connection stiffness in the tests. The effect of timber shear stiffness on the strength reduction factor was also investigated. At last, elastic buckling load of timber lattice shells could be estimated multiplying reduction factors α₀ and β(κ) to linear buckling load. The findings are summarized as follows.
 (1) The maximum flexural strength of the proposed connections ranges 0.34 to 0.87 times the laminated material bending strength M_b, and the normalized rotational stiffness ratio κ (Eq. (56)) ranges from 7.5 to 22. This rotational stiffness ratio values indicate that the proposed connections are categorized as medium stiffness for single layer timber lattice shells.
 (2) In tee flange connections, the rotational stiffness and flexural strength increase as the wrap length elongates. The wide flange connections exhibited maximum flexural strength, though the rotational stiffness is smaller than other connections with equivalent wrap length,
 (3) Evaluation formulas to calculate the rotational stiffness and the flexural strength for the proposed connections are provided. The values calculated by the formulas generally correspond to the test results with a safety margin.
 (4) The knockdown factor β(κ) for the buckling load of timber lattice shells in of each connections range from 0.74 to 0.87, which is applicable for practical design of single-layered timber lattice shell roofs.
 (5) The elastic buckling load of timber lattice shell roofs with the proposed connections can be evaluated multiplying the reduction factor γ_t , the knockdown factor β(κ) f and the reduction coefficient α₀ which can be assumed 0.9 to the linear buckling load.

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 1. Introduction
 This paper describes three-dimensional FE analysis for a six-story reinforced concrete(RC) wall frame building specimen in a shaking table test. Pretest and posttest analyses were conducted here to investigate analytical accuracy of FE analysis for nonlinear dynamic response of RC buildings. Furthermore, the structural performance of each primary seismic resistance member was investigated using the analytical results.
 2. Outline of analyses
 Two kinds of analysis model were used to evaluate influence of modeling methods to analysis accuracy. One was a solid model which reproduce configuration of specimen in detail by hexahedral elements, as shown in Figure 3(a). The other one was a shell model by multilayer shell elements which assumed plane stress problem in each layer, as shown in Figure 3(b).
 3. Analysis results
 Remarkable differences between analysis results of the shell model and that of the solid model were not found as shown in Figure 4 and Figure 8. The pretest analyses satisfactorily predicted the failure mode and nonlinear response of the specimen at an excitation, in which the specimen reached its maximum capacity, as shown in Figure 4 and Figure 6. However, for the excitations performed before the specimen had reached its maximum capacity, the pretest analyses tended to overestimate the displacement responses. Posttest analyses were conducted with the input conditions and material properties measured in the test. The posttest analyses reproduced the test behavior from elastic point up to failure with improved accuracy as shown in Figure 8 and Figure 9.
 4. Study of structural performance of primary seismic resistance wall
 Shear span ratio, maximum capacity, and skeleton curves of each primary seismic resistance walls were investigated using the analytical results. The findings of this study are as follows.
 1) It was found by investigating elemental stresses that shear span ratios of the walls were less than 1.0.
 2) Although shear capacities of the walls by FE analysis corresponded well with those calculated by standard minimum evaluation formula, were less than standard mean evaluation formula.
 3) Although sliding shear capacities of walls calculated by evaluation method of previous studies corresponded well with maximum shear capacities by FE analysis for 1^st story walls, were far higher than those for 2^nd story walls. As the reason for that, it was guessed that boundary conditions of 1^st story walls were different from those of 2^nd story walls. As the results, the boundary condition should be considered on evaluating the sliding failure of walls.
 4) Skelton curves of relationships of shear force and drift angle of the walls, which was obtained by FE analysis, could be evaluated well by previous evaluation method.

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 The bending strength of H-shaped beam is governed by material and geometric nonlinearity. Many estimation equations of the bending strength have been proposed and are currently used for actual structural design. One problem is that they have been determined experimentally because the theoretical relationship between the bending strength and such nonlinearities has not been clarified. This prevents us from evaluating the effect of residual stress and initial deflection for the estimation of the bending strength. To overcome this problem, this study aims to understand the relationship between the bending strength and the nonlinearities using finite element models.
 In the previous report, the estimation method considering only material nonlinearity is proposed and the validity of the method is investigated. In this report, the method is extended to consider the geometric nonlinearity and the method is verified in the case where only geometric nonlinearity is included and in the case both material and geometric nonlinearity is included.
 Firstly, the analysis considering only geometric nonlinear is conducted. The results shows that the increase of applied bending moment becomes less and less according as out-of-plane displacement increases, though the out-of-plane displacement has little effect on the buckle strength. From this result, it can be said that the maximum strength would not be governed by the buckle strength drop due to geometric nonlinearity. Therefore, the authors assumed that the maximum strength is characterized by suppression of load increase caused by the out-of-plane displacement, which is defined as the displacement in direction of mode vector. Based on this assumption, it is possible to calculate the amount of out-of-plane deformation and to estimate the drop of the maximum strength by converting it to the buckle strength drop. By conducting analysis changing the shape and the amount of initial deflection, it is indicated that the amount of the influence of geometric nonlinearity is determined by the product of the vector representing the initial deflection and mode vector. Because the mode shape differs according to the bending moment distribution, it means that, even the shape and the amount of initial deflection is the same, the drop of the maximum bending strength due to the geometric nonlinearity is affected by the bending moment distribution.
 Next, the analysis considering both material and geometric nonlinearity is conducted. The influence of the initial deflection appears as “1. Rigidity reduction due to material nonlinearity caused by the change in progress of plasticization” and “2. Rigidity reduction due to geometric nonlinearity”. In the proposed method, the former is considered as the buckle strength drop and the latter is considered as the amount of out-of-plane deformation, which is converted to the buckle strength drop, and it is confirmed that the proposed method is valid in the case where both nonlinearities are included. Moreover, by observing the buckle strength drop in detail, it is possible to investigate the degree of the influence of material (“1.”) and geometric (“2.”) nonlinearity respectively by using the proposed method. The proportion of “1.” and “2.” differs according to the value of the lateral-torsional slenderness ratio, λ_b, and it is shown that, in a range where λ_b is around 0.9, the influence of material nonlinearity (“2.”) appears first, and that of geometric nonlinearity (“2.”) appears next.

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 Recently the earthquake resistance of public buildings such as schools has progressed, but seismic diagnosis and seismic retrofitting of private apartments have not progressed.
 So we deal with an apartment which was built before 1981, and propose the seismic reinforcement method for it. Now we reinforce the apartment on the balcony and common corridor, because it is required to do seismic reinforcement construction of apartment at the out of the private area.
 We created RC frame, reinforcement method was attached steel arch in RC frame.
 Reasons for attaching steel arch reinforcement are as follows.
 1) It has less influence on traffic lines compared with brace reinforcement
 2) The curved portion of the arch can smoothly transmit the horizontal force from the girder to the column to the lower part of the building.
 3) Spiral reinforcement isn't set between the RC frame and steel arch, in order to reduce the decrease of the opening height when the residents take refuge.
 The purpose of experiment is set in confirming the effect of reinforcement by steel arch. Two 1/4-1/5-scale RC frames were tested cyclic lateral loading. Next they were reinforced by steel arch. And the reinforced them were done experiment.

 We obtained the following conclusion from this experiment.
 1) The initial stiffness of specimen after reinforced by steel-arch increased about 70% than it of specimen before reinforcement. The strength on R=0.5% of specimen after reinforcement increased about 80% than it of specimen before reinforcement. The hysteresis energy of specimen after reinforcement increased about 50% than it of specimen before reinforcement.
 2) The initial stiffness of specimen with arch-corner-plate was 18% higher and the strength of specimen with arch-corner-plate was 13% higher, than specimen without arch-corner-plate.
 3) In the case of reinforced by steel-arch, the maximum load was reached in the vicinity of R=0.8%. The shear cracking occurred in the column. The lateral load decreased but the load at maximum deformation at the initial cycle of R = 2.0% was 8-17% less than maximum load. The large reduction in yield strength were not observed.
 4) Axial force and bending moment of the steel-arch became large at the curved portion, and they can be dispersed by attaching the arch-corner-plate.
 5) Hysteresis energy of specimen after reinforcement on maximum load was Approximately 4 times than specimen before reinforcement on R=0.5% load. And Hysteresis energy of specimen after reinforcement on maximum deformation was Approximately 11 times than specimen before reinforcement on R=0.5% load.
 6) Maximum yield strength when steel-arch is attached can be roughly calculated by the accumulated strength of RC frame and steel-arch.

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 The importance of precaution against unexpected earthquakes was highlighted after the 2011 Great East Japan Earthquake. While Nankai trough mega quake and a Tokyo inland earthquake are expected in the near future, it is important to prepare for disasters in metropolises and other urban areas. Since high-rise steel buildings in urban areas are the basis of civic and business life, adequate methods of evaluating their structural soundness, which enable an immediate judgment of the prospect of business continuity and the early recovery of such buildings after the disaster, are required. For this purpose, it is necessary to clarify the collapse behaviors of such buildings.
 A number of experimental and analytical studies on collapse behavior of steel moment resisting frame have been conducted by many researchers. However, most specimens were a few stories models, which are much smaller than actual buildings. There have been no shaking table tests simulating the entire high-rise steel moment frame. It is necessary to clarify the relationship between the extension of damages of the components and the collapse behavior by large scale shaking table test with many-story frame specimen.
 This paper reports on a large-scale shaking table test of a high-rise steel building conducted at the facility called E-Defense. The building specimen is a 1/3-scale 18-story steel moment frame designed and constructed according to design specifications and practices used in the 1980s and 1990s. The input motion is a long-period and long-duration strong ground motion simulated considering a Tokai, Tonankai and Nankai coinstantaneous earthquake. The specimen was subjected to a series of progressively increasing scaled motions until it completely collapsed. At first, the yielding was observed at the beam-ends along the lower stories and the column bases of the first story. As the ground motions became stronger, cracks initiated at the welded moment connections, and then fractures spread in the beam flanges of the lower stories. As the shear strength of lower stories decreased owing to such damage, the story drifts significantly increased and the frame finally collapsed. The main cause of the collapse of the test specimen was the extension of the fractures of the lower flanges at the beam-ends of the lower stories. Furthermore, the changes of the natural period, damping ratio, and participation vectors were calculated from the test result data and the relationship between the changes and the extension of the structural damages like local buckling or fracture was presented.
 In addition, a numerical analysis was performed in advance of the shaking table test. The deterioration hysteresis model was used which can represent the characteristics after fracture of lower flange at beam ends. The analysis results were roughly similar to those of the test in terms that the analysis model exhibited the fractures of the lower flanges at the beam-ends of the lower stories and then the significant deformation, as observed in the shaking table test.

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 EWECS (Engineering Wood Encased Concrete-Steel) composite structural system consists of concrete, steel and glued laminated timber. In experimental studies on EWECS columns and EWECS beam-column joints, it was confirmed that the EWECS structural system showed good and stable hysteresis characteristics. However, the structural performance of the EWECS column-beam joints with slab have not been examined in these studies. In this study, static loading tests and three-dimensional (3D) FEM analyses for EWECS column-steel beam interior joints with slab were conducted to investigate the structural performance. Outlines and results of the tests and analyses are described in this paper.
 Four EWECS column-steel beam interior joints with slab which were one-half scale were tested. The variable investigated were the thicknesses of steel web in joint panel, and the cross-sectional shape of the column steel. Specimens BF and BFO which were designed to be a flexural yielding of steel web had a thick web. On the other hand, Specimens JS and JSO, which were designed to be a shear failure of the joint panel, had a thin web in the joint panel. In addition, Specimens BF and JS had an H-shaped steel of column, and Specimens BFO and JSO had a cross-shaped steel of column and transverse steel beam.
 The shear failure of joint panel occurred in Specimen JS. The flexural failure of the beam occurred in Specimens BF, BFO and JSO. The maximum capacities of the Specimens BF, BFO and JSO which had flexural failure of the beam were almost the same. That of Specimen JS which had a panel shear failure was lower than that of specimens which had a flexural failure of the beams. It was confirmed that shear forces of all specimens after maximum capacities decreased slowly regardless of failure modes. The flexural strength of the steel beams with slab calculated by the superposed strength theory and the shear strength of the joint panel calculated by the proposal in Ref. 6) agree with test result for all specimens. However, the failure mode by the ultimate strength evaluation for Specimen JSO which had a cross-shaped steel of column did not agree with that of the experimental result. Furthermore, the evaluation methods of panel shear strength did not take into account the effect of the slab.
 Analytical results of shear versus drift angle relationships and stress transitions of the steel web in the joint panel showed good agreements with experimental results in all specimens. It was indicated from the analytical results that the high compressive stresses were occurred of concrete in the joint panel regardless of the confinement effect from steel due to the compressive force transmitted from the slab concrete. Moreover, the shear forces of the beams on both sides and the lower column decreased drastically at the steel flange in the joint panel. On the other hand, that of the upper column decreased drastically from the upper end of the slab to the upper flange of the beam. Therefore, the effective depth and height of the joint panel were assumed to be the distance between the centroids of the steel flanges in the column, and that between the centroids from the slab to the lower flange in the beam, respectively. The effective width was assumed by the method in Ref. 8) considering the effect of the slab width subjected to compression. The panel shear strength modified AIJ standard for SRC structures based on the analysis results can evaluate the maximum capacity of EWECS column-beam joint with slab which had an H-shaped steel of column.

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 Since people's awareness about the importance of energy conservation and recycling of materials has increased in recent years, various projects to build a recycling society have been initiated. In the field of architecture also, we are faced with the need to recycle resources and reduce environmental impact, by taking actions to utilize renewable resources. Therefore, we have directed our attention to the recycling of aluminum and wooden materials as renewable resources from the viewpoint of solving global environment issues.
 With this background, this paper proposes a composite structural column made of two different materials, aluminum and wood, in which wood is introduced into the aluminum box sectional member.
 Since aluminum material requires a step of anodized aluminum welding, it has been thought that utilization as a structural member was unlikely to spread. However, since the approach proposed in this paper does not necessitate such welding, this opens the possibility of using joint hardware pieces such as screws and bolts in the same manner as used when jointing construction members in steel structure construction and the timber frame method.
 Furthermore, with the use of a composite structural column as proposed by this paper, we conclude that the different materials of the composite structural column can make up for the drawbacks of each material, for example, controlling variations in bearing force in the timber and preventing local buckling in the aluminum.
 Through this study, we plan to verify, with loading tests, whether such a composite structural column which is made of an aluminum box section with a wood member inside, is actually applicable to utilization in the field, and from the test results obtained, to introduce a formula for evaluating bearing force to identify the characteristics and values in use for the composite structural column.
 We compared the characteristics of bending, shearing and compression of three specimens of an aluminum box section, a simple wood column and an aluminum-wood composite structural column, using pure bending tests, shearing tests, short column compression tests, and bending-buckling tests. By doing various experiments, we aimed to determine the structural characteristics of the composite structural column through comparison with the characteristics of a simple wood column to identify prospective application fields.
 From the results of the experiments, we determined the structural characteristics of a composite structural column which is composed of an aluminum box section with wood inside, and proposed a related bearing force evaluation formula. In comparing the composite structural column specimen with a simple wood specimen and a specimen of aluminum box section, we confirmed that the composite structural column has improved mechanical characteristics such as bearing force and deformation performance. This composite structural column was verified to have a sufficient performance for practical application in the field.

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