登載誌：構造工学論文集 Vol.68B、415-424頁、2022年4月

本論文は取り下げたい旨の申請が著者からあり、これを承認した。

日本建築学会 構造工学論文集編集小委員会

Based on the pole allocation method in control theory, the authors’ previous research found out a fundamental closed-form equation governing a three-lumped-mass stick-shape shear model for a building. Through the selection of appropriate model parameters, the simplified model can represent an earthquake-resistant structure, a base-isolated structure, an interstory-isolated structure, or a passively controlled structure with a tuned mass damper or viscous interstory dampers. The equation explains how the model parameters are related to the control target and generally proves the trade-off relationship in the passive control effect. The present study similarly applies the pole allocation method to a multi-lumped-mass stick-shape model to provide the trade-off relationship with higher generality. The newly introduced equation has the same form as the previous research indicated. Next, this study discusses the installation distribution of interstory dampers from a viewpoint of modal damping as control target.

This paper proposes a new procedure for predicting the maximum seismic response based on the capacity spectrum method (CSM) for the passively controlled suspended ceiling structures named “Pulley Damper Ceiling System (PDCS)”. The structural system has a supplemental nonlinear viscous damper and a bilinear hysteretic damper in parallel with displacement amplification mechanisms of block and tackle pulley system. The single degree-of-freedom model of the PDCS is initially discussed. The accuracy of a simplified calculation method for obtaining the structural equivalent damping coefficient, determined by the sum of the inherent damping and the square root of sum of squares (SRSS) of each damping provided by the nonlinear viscous damper and the bilinear hysteretic damper, is verified by comparing with the full-scale shake table test results of the PDCS. Then, the pseudo capacity curve of the structure is generated by continuously plotting the transition of maximum force and displacement values under different amplitudes of sinusoidal waves. Finally, the availability of the response prediction based on proposed CSM procedure considering floor response spectrum (FRS) is examined by the comparison of time history analysis results, and the sufficient accuracy to evaluate the seismic response is confirmed.

Following earthquakes, it is essential to immediately assess the damage sustained in buildings and make judgments about the safety of their reoccupation. As instrumenting buildings with accelerometers is expensive, damage assessments are primarily done by entering the building and performing visual observations. As an alternative, the emergency gas shut-off feature available in gas meters installed in buildings is considered as a potentially effective indicator for identifying damage in structures. In this study, the commonly used gas meters equipped with `rigid ball type seismic sensor' are subjected to earthquake demands via shake-table testing to evaluate the shut-off characteristics.

The authors focus on the performance prediction of yielding dampers for seismic isolation structure. The performance of these devices is mainly evaluated by two characteristics. The one is load-displacement characteristics, and the other is the durability in the cyclic loading test. The research consists of two phases. First, proposing yielding damper with C4641 Naval brass and the modeling of non-linear mechanical properties which is used in the FEM analysis based on tensile test and load-displacement characteristic test for specific damper prototype. Second, the optimization was performed by applying concept of Quality Engineering with the L12 orthogonal array and FEM analysis and the effects of each design factors of prototypes on the performance of the damper were clarified. The authors conclude that the effect of optimization has been confirmed.

In order to easily assess the damage caused by earthquakes in low- and mid-rise building complexes, this paper proposes a simplified method for assessing the damage ratio in real building complexes by combining a seismic evaluation method based on the energy balance and reliability theory. This method enables the effect of dissipation damping to be taken into account, and is effective for the evaluation of the largest foreshocks and aftershocks in addition to the main shock. A comparison of the damage ratio calculated using this method with the actual damage ratio from the 1995 Hyogo-ken Nanbu Earthquake showed that the two ratios generally matched with each other. In terms of applications, this method provides a standard for calculating the base shear coefficient of low-rise reinforced concrete buildings for continued use after an earthquake from the viewpoint of performance design.

The purpose of this paper is to clarify the reason of the difference in damage between Tofukuji Temple and Toji Temple in the 1596 Keicho-fushimi Earthquake. First, the differences of building damage at two temples are summarized. Next, we conduct microtremor measurements of the buildings and ground in two temples. These results reveal differences in amplification characteristics of ground motions due to the subsurface structure of the Kyoto basin. Therefore, we examine the differences in amplification characteristics of pulse-like ground motions and their consistency with the damage situation in the 1596 earthquake using two-dimensional ground models.

In this study, a static vertical load test was conducted on the uppermost layer of the 1/10 model of the Hokiji three-storied pagoda.

The test conditions were (1) Only rafters are used without using roofing boards, (2) Presence or absence of intermediate support for Gagyo, (3) Roof load shall be 2940N /㎡, (4) Temperature control with experimental enclosures and air conditioning.

As a result of conducting the experiment, the following conclusions were obtained. (1) The middle support of Gagyo reduced the sagging of Gagyo and Kayaoi by 60%. (2) The intermediate support of Gagyo reduce the bias in the stress of the members that make up the roof ,and changed to the support of the whole. (3) The bending strains of Gagyoand Kayaoi suggested that the deformation of Kayaoi is affected the deformation of Gagyo.

Sliding bases decrease the seismic load to structures. They make both the decrease of the maximum displacement response and the slide displacement of the structure. In this paper, sliding bases are adopted to a Japanese wooden house. Both the demand base shear and the maximum slide displacement of houses are proposed. As a result, the sliding bases with 0.2 static friction coefficient makes that no slide displacement is calculated in rare earthquakes. And the storey displacement angle of the house with 2.0 bearing wall sufficiency ratio is less than 1/120 rad in extremely rare earthquakes. Some observed earthquakes make the slide displacement over 600mm.

Passive controlled shear wall for wooden construction with high damping rubber damper to prevent the degradation of seismic performance during repeated severe earthquakes is proposed in this study.

In this paper, shaking table tests of the full scale two-story wooden structure composed of proposed shear wall were described.

In addition, we tried to calculate the seismic response of shaking table tests using time history response analysis.

As the result, it is confirmed that the proposed shear wall is effective to reduce the degradation of seismic performance to repeated earthquakes in comparison with plywood conventional shear wall.

Few studies have focused on the failure behavior of large dimensional glulam beam-end joint by drift-pined joint with inserted steel plate. However, this type of joint is widely used in mid-rise and high-rise timber building. Thus, in this paper, shear tests for the joint were conducted to find out the failure behavior and shear behavior of the joint. Furthermore, surface strain distribution of the joint was analyzed by digital image correlation. Finally, it was investigated validity of the existing evaluation method for estimating failure force. Based on the above results, the failure behavior of large dimensional glulam beam-end joint were reported.

To effectively use the large supplies of wood material obtained from forest thinning, research focused on developing cross-laminated timber (CLT) structures is increasing globally. However, the earthquake resistance of CLT structures is considered insufficient owing to the relationships between the force and deformation of CLT structures exhibiting pinched hysteresis behavior with slippage.

This paper proposes a CLT wall with a self-centering function owing to pre-stress by prestressed concrete steel bar (P/C rod) and a series of so-called shear link type passive control systems to effectively reduce the seismic response and damage to CLT structures. For a comparison, static cyclic loading tests were conducted using both CLT specimens with the self-centering function and friction damper and general CLT structure. The mechanical behavior of the specimens was discussed by referring to the relationships between the force and deformation and the friction damper hysteresis and P/C rod axial force.

In this paper, the property of energy conservation and the dynamic responses are analytically examined for the bilinear restoring force characteristics. Next, the restoring force characteristics of wooden frameworks are clarified experimentally. The frameworks have bearing wall elements and steel bar braces that are placed in parallel. The steel bar braces are placed to add the secondary stiffness after yielding of the bearing wall elements of the frameworks. There is a loose hole on the prate at the end of the steel bar brace.

The bending failure of full-culm bamboo is usually preceded by bending failure perpendicular to the fibers of the bamboo culm walls. Therefore, it is important to evaluate the stress perpendicular to the fiber that accompanies the bending of the bamboo culm. Brazier effect is considered one of the factors that cause this stress. In this paper, we discuss the bending failure mechanism and bending strength of round bamboo culms with formulation of the Brazier effect theory, numerical analysis, and experiments.

According to the Brazier effect theory, when the bending moment for the bamboo culm is small, the bending stress perpendicular to the fiber is about 6 % of the stress parallel to the fiber. Also, the finite element analysis results and the Brazier effect theory showed good agreement in some conditions. The stress perpendicular to the fiber by numerical analysis lies between the linear approximation and the Brazier effect theory and is affected by the internode length. As a result of the bending experiment using Madake bamboo, the stress distribution in the part of the bamboo culm that is not directly subjected to the external force agrees well with the Brazier effect theory. However, it was observed that at the point where the concentrated load was applied, a large additional bending stress perpendicular to the fiber was generated in the culm wall, leading to bending failure of the bamboo culm.

We propose a method for topology optimization of braced frames under static seismic loads using Deep Deterministic Policy Gradient (DDPG) and Graph Convolutional Network (GCN). The structure is interpreted as a graph where structural elements and element configurations are represented by the node feature matrix and adjacency matrices, respectively. Using this graph representation, the DDPG agent with GCN architecture can observe the properties of the frame, and make the decision to either add braces into the frame or enlarge sections of frame elements by selecting from a list of available sections. During the optimization process, the initial structure that cannot withstand the seismic load is modified by the agent until all constraints are satisfied. The trained agent can be applied to frames of different sizes and can obtain competitive results with less computational cost compared to the genetic algorithm.

An evaluation method of structural damage probability of floating offshore wind turbines under wind and wave actions is presented. The structural damage probability of the floating wind turbines is analyzed by using the first order reliability method in the structural reliability evaluation. In the evaluation of the probability, the response analysis results of the floating wind turbine for the wind and wave actions are used. The response for the action by the mean wind speed is analyzed by using the statically equation of equilibrium. On the other hand, the response for the dynamic actions by the variable wind speed and the wave is analyzed by using a mode superposition method and a stationary random vibration theory. Numerical model of the floating wind turbine is discretized by finite elements, whereas interface of the floating wind turbine and the sea water is discretized by boundary elements. Moreover, variation of the damage probability of the floating wind turbine for different wind speed is discussed by using the proposed method.

In various situations of natural disasters, severe damages to structures were caused in unexpected scales. To avoid damages to socially important structures, breakdown behaviors should be taken into account during the process of structural design. In most previous studies so far, collapse behaviors of structures has been studied by model experiments. However, experimental studies have many restrictions, such as cost and experiment facilities. As an alternative approach, Peridynamics Fracture Mechanics has been recently investigated, and in this study the possibility and applicability of the new mechanics as a numerical analysis method is investigated by adopting Architectural Materials.

The present study presents a new FEM element for buckling analysis of members of H-section and its application to spatial structures. The element is fundamentally composed of three parallel beams together with two struts normal to the three elements, enabling a consideration of flexural-torsional buckling. The present study, first, performs static analysis of members under torsional moments. Second, the study performs buckling analysis of members subjected to axial forces, followed by lateral buckling analysis of members under bending moments at both ends. Through the comparison of the results with the solutions based on differential equations, the study validates the proposed element. Third, the study extends analyses to two structures which represent the fundamental structural characteristics of spatial structures, also considering the effect of stiffening members added to spatial structures. Finally, based on discussions, the authors prove the effectiveness of the proposed element in the case where members of H-section adopted in spatial structures are subject to flexural-torsional buckling.

A new uncertainty analysis method is developed for planar frame structure models equipped with oil dampers of linear and nonlinear force-velocity relationships. The structural analysis software SNAP^® is collaborated with previously proposed uncertainty analysis method called NURP to obtain the maximum structural response when the damper characteristics are varied. In order to consider the uncertainties in the input, the critical double impulse is employed in addition to standard design ground motions, and we proposed the practical solution to use it in the structural analysis software. The validity of the proposed uncertainty method for frame structure models is investigated by comparing the result with maximum response derived by genetic algorithms. As a simplified method to evaluate the maximum value of the frame structure response, a method that uses a shear model equivalent to the frame structure model is also proposed.

A new robustness evaluation method based on the specified story ductility ratio is proposed for a building model with uncertain oil dampers. Since the influence of input motion uncertainty on the response variation can be simply taken into account, the critical double impulse input is used instead of input ground motions. In the proposed method, the robustness function is derived as a function of the input velocity amplitude for a specified ductility ratio. This procedure is suitable for the performance-based design. A robust optimal design method on damper placement is also presented based on the proposed new robustness function. Numerical examples of robust optimal design of dampers are presented for a 12-story elasto-plastic building model with linear oil dampers.

In the biomechanics field, tensegrity structures are considered to be similar to the human skeleton and the joint. Oh proposed a biotensegrity model that mimics the human spine and presented a shape control strategy, which leads to the optimization problem with the lengths of the tensile members corresponding to the muscle and tendon as design variables. This study extends previous shape control methods by incorporating strategies to avoid obstacles. As the methodology, the potential method, which has been applied in robotic engineering, is adopted. This method derives an appropriate avoidance path from the potential field function.

The purpose of this paper is to verify the possibility of automatic deployment of an arch-shaped scissors truss by using shape memory alloy springs as actuators. For this purpose, we first conduct a construction experiment to confirm whether automatic deployment is possible by heating the shape memory alloy springs installed on the scissors truss by applying an electric current. In addition, since it is difficult to apply the proposed deployable structure without clarifying the specifications of the springs necessary for movement, the second purpose of this paper is to propose a method for determining whether automatic deployment is possible at the time of design. At that time, we try to evaluate whether automatic deployment is possible by focusing on the potential energy of the structure.

This paper applies a discretization formulation of the finite element method using the minimal surface for membrane structures and denotes an initial shape analysis procedure for a cable-reinforced HP-type suspension membrane structure and a cable-reinforced pneumatic membrane structure as numerical analysis model. In the computation process of cable introduction, moving boundaries are set and the cable is introduced step by step to denote a stable numerical computation procedure. In addition, finite elements of the initial shape obtained assuming a time history response analysis by wind are subdivided to compute the minimal surface again. To verify the equally tension property of the initial shape obtained based on minimal surface, a stress deformation analysis using the finite element method with the coordinate assumption is performed. For the pneumatic membrane structure, an example of stress deformation analysis due to an increase in internal pressure assuming strong winds is shown. The above clarifies the validity of this numerical procedure.

This paper proposed an optimization technique to including buckling obtain the optimal wave directions and wave heights of corrugated shells. The finite element method is applied to the structural analysis of the corrugated shells. Rhinoceros and Grasshopper are used for modeling and optimization of the analytical model. The constituted law of an anisotropic flat plate is used for the material of the shell element to achieve the same effective stiffness as the corrugated plate. The objective functions are the strain energy under self-weight and the buckling load coefficient from linear buckling analysis. The wave direction is defined by the contour direction of a NURBS surface in Rhinoceros, the wave height is given by the z coordinate of another NURBS surface. The design variables are the control points of the NURBS surface. A genetic algorithm plug-in on Grasshopper is used for optimization. The optimal solutions for a cylinder shell and an EP shell are shown as numerical examples. The optimal wave directions and heights with low strain energy and high buckling load coefficient were obtained, thus confirming the effectiveness of the proposed method.

Primary load-bearing members used in glass structures, such as columns consisting of glass panels, are frequently subjected to in-plane loading. Its allowable stress for safety design appears to be a significant subject. By analyzing the results of static (without repeated loading) and cycling compression loading tests, the authors explore the mechanical features and failure mechanism of the tempered glass panels subjective to in-plane compression loading, including its ultimate stress and buckling load. In addition, a statistical method based on the experimental results is adopted to evaluate the allowable compressive stress. The experimental results show that the ultimate loads of specimens with high slenderness ratios satisfy Euler's critical load formula. In contrast, the ultimate loads of specimens with low thickness ratios distribute in a certain variance range. For the cycling loading test, after 30 times of repeated loading with maximum stress equivalent to 2/3 of the ultimate static stress, the average strength is almost the same or bigger than that of static loading tests. No fatigue fracture due to repeated loading was found for the tempered glass panels. Consequently, the allowable stress for in-plane compressive loading can be formulated based on Euler's critical load formula for a glass panel with a bigger slenderness ratio. The formulation for the allowable compressive stress of a glass panel with a smaller slenderness ratio is promoted using statistical analysis with a 95 percent confidence level for the safety design.

The purpose of this study is to clarify the stress distribution of the cross-section at the simple superposed strength of concrete filled square steel tubular section. The moment-axial force relationships correspond to the simple superposed strength are calculated based on the Navier’s hypothesis. Analytical parameters are strength of concrete and steel tube and the width-to-thickness ratio. The stress or strain at the outermost edges of concrete and steel tube cross section with the stress or strain at allowable stress of the respective materials are compared and the relationship between the stress or strain of the cross-section at the simple superposed strength and the analytical variables are discussed.

This paper discusses on R/C interior step beam-column joints with headed anchor for beam longitudinal bars, developed to streamline the works of reinforcing for R/C interior step joints. In general, beam longitudinal bars of step beam column joints are applied 90°-degree hook in step beam-column joints. In R/C buildings, step beam column joints are sometimes planed for architectural planning reasons. Nevertheless, interior step beam-column joints reinforcements are congested and 90°-degree hook of the left and right beams may be the case these hooks are overlap. In order to consider interior step beam-column joints design method, four specimens with beam-column strength ratio approximately 1.0 and 1.5 were tested. Regarding step beam-column joints, from the crack behavior, the stress transfer mechanism depends on positive and negative loading and is considered to consist of two struts which are formed by the balancing of the compressive forces concentrated at the ends of the column and beam and the balancing of the headed anchorage reaction forces. The stress transfer mechanism consisting of these two struts was modelled and proposed as a “double strut model”. A design method of R/C step interior beam-column joints based on the double strut model is also proposed. It provides sufficient satisfaction as to the interior step beam-column joints experimental test results.

Bi-directional loading tests on reinforced concrete walls were conducted with out-of-plane deformation and height of contraflexure point as parameters. The experimental results were discussed with FE analysis. The reduction of the in-plane load capacity due to out-of-plane loading was smaller when the wall was bent in single curvature compared to when in double curvature in the out-of-plane direction. An evaluation method of the in-plane shear capacity considering tri-directional loading proposed by the authors can capture the experimental results of the nine wall specimens with a margin of error ranging from -3 to +9%.

In recent years, studies on crack propagation analysis and evaluation methods for RC structural members have been carried out for the sake of reparability performance. The purpose of this study is to develop a simple method for estimating crack propagation without using advanced and complicated analytical techniques. This paper is divided into two main chapters: The first focuses on the relationship between axial strain distribution and crack length obtained from an experimental result to improve the existing damage estimation method. The second is a study of the applicability of the proposed theory to structural damage estimation by combining it with static incremental analysis.

At present, the highest high-rise RC building in Japan is over 200 meters high. All columns from the first to the 13th floor of the building are applied high strength steel fiber reinforced concrete columns （HSFRC）to control damage under huge earthquake loading. The high strength steel fiber reinforced concrete columns are contain 1.0% steel fiber by volume. It is the first time to apply much steel fiber for high strength concrete columns. Nevertheless, there is no established design equation for high-strength SFRC columns. Therefore, authors have conducted an experimental study of HSFRC columns since 2020. A total of 15 specimens were conducted. In this research, 13 specimens’ experimental data are used. The shear strength equation based on truss arch theory with the volume ratio of steel fibers as a variable factor is proposed as a design equation for high-strength steel fiber reinforced concrete columns.

In the 2011 Tohoku Earthquake, many buildings were collapsed or overturned, and a number of outer concrete walls were broken by the hydro dynamic pressure due to Tsunamis. Out-of-plane strength of wall are usually not concerned in the seismic design and a few static loadings tests verify the actual nonlinear out-of-plane response of concrete walls. In a past study, an out-of-plane strength of outer concrete walls damaged by 2011 Tohoku Tsunami was evaluated based on the plastic hinge mechanism. In this study, the strength evaluation method is verified by the hydro static loading test on the concrete walls, and the out-of-plane strength are compared by the test between the bare concrete walls and walls reinforced with the polyester fiber sheets.

For the renovation of the reinforced concrete boxed-wall building, a new opening would be constructed on multi-story wall frame, and local retrofit with post-installed adhesive anchors would be applied. In this study, evaluation method of tensile strength for a post-installed adhesive anchor embedded in wall plane was proposed. The non-fixed bond-tensile test of anchor specimens embedded in wall-slab specimen was conducted. The parameter of specimens are embedment length of anchors, wall thickness, and wall shapes. Tensile strength of the anchors could be evaluated due to previous formula with the assumption of the effect of local retrofit on bottom floor wall and floor slab.

This paper examines the wall and column wall ratios of low-rise RC buildings to determine wall and column wall ratios that would limit the degree of building damage to a level no greater than slight damage for the purpose of continued use of the building after a mainshock, foreshock, or aftershock. Based on the energy balance in seismic response, a simple evaluation formula was derived to calculate wall ratio to a strength that would allow walls to withstand a level of damage up to shear cracking after an earthquake. The applicability of this formula was confirmed by comparing the wall ratio of actual buildings based on earthquake damage surveys with the results of this evaluation formula. The results indicated standards for wall and column wall ratios that enable buildings to withstand being hit by one to three earthquakes of an extremely rare level, as described in the notice, and still sustain a level of damage below shear cracking.

A formula to predict the peak displacement response for low-to-mid rise buildings deforming in flexure had been previously proposed. This formula is applicable to buildings with fundamental periods within the constant velocity range of the design spectra and is a function of the damping correction coefficient and the ductility factor.

In this study, the equivalent damping coefficient was calculated considering the energy dissipated through a one-cycle loop encompassing the maximum response obtained from earthquake response analysis. Furthermore, the damping correction coefficient equation based on the ductility response and elastic damping coefficient was found to be reasonably accurate based on structural analysis. The product of the response reduction factor due to damping and the square root of ductility response was approximately 1.0, which allowed the previously proposed displacement estimate equations to be simplified further. In addition, the previous method underestimated the displacement response at greater ductility values, so a new equation was proposed for such cases.

Loading tests and numerical analyses using the finite element method were carried out to clarify the deformation characteristics of a concrete-filled double steel pipe pile subjected to a horizontal load. The diameter and length of the concrete-filled double steel pipe pile were about two times and ten times the inner pipe diameter, respectively. The results indicated that the steel pipe and concrete behaved as a single unit from the pile head to the central part of the concrete-filled double steel pipe pile. On the other hand, this unity was lost in the length range of 3 to 4 times the diameter of the inner steel pipe from the bottom end of the concrete-filled double steel pipe pile. This is due to slippage at the boundary between the steel pipe and the concrete, and local compressive deformation of the concrete. We attempted to simply calculate the deformation of this pile when subjected to a horizontal load by constructing a beam spring model that combines the interface springs between the steel pipe and concrete and Timoshenko beams. The applicability of this calculation method was verified by comparing the results with those of loading tests.

In truss tower structures, if the main posts are not strong enough against compressive forces, the structure may collapse triggered by the buckling of that ones. With the increase in the assumed load following the revision of design standards, it is necessary to establish a reinforcement method for the main posts of steel tower for power transmission. In this study, the reinforcing effect using flat bars was verified by member compression tests, and an evaluation formula was proposed to estimate the bearing compression capacity of the flat bar reinforced members.

Many buildings had stopped their service due to damage to non-structural members including ceilings, partition walls and piping after large-scale earthquakes. In particular, piping-failure-caused water leakage damaged electronic equipment and resulted in a loss of functionality of the building. Cyclic bending tests are conducted of carbon steel pipes for water supply piping with nominal diameters of 25A, 40A, 50A and 80A to evaluate their deformation capacity and strength. The results are summarized as follows.

1. The failure pattern depends on the pipe diameters. The pipes with a nominal diameter of 25A crack at the thread part and then fracture. On the other hand, the screw part of the 40A, 50A and 80A pipes are deformed and eventually come loose.

2. The bending strength begins to decrease when the deformation angle reaches about 0.03-0.07rad independent of the pipe diameters.

3. The skeleton curves of moment-deformation angle relation are obtained for pipes with different diameters. The maximum deformation angle of the pipe joint needs to keep under about 0.03 rad to prevent fractures.

Exposed-type column bases are classified by two yield types, i.e., anchor-bolt type, and base-plate type. Restoring force characteristics are slip-type and maximum point orientation type respectively. The characteristics of damage distribution in steel frames with exposed-type column bases have been clarified by many past studies. However, the literature concerning quantitative evaluation and prediction formulas is limited. The prediction formulas are needed to design such structures avoiding damage concentration as much as possible. In this paper, the damage to column bases, the upper beam of the first story, and inside the first story in steel frames with column bases that have elastic perfectly plastic restoring force characteristics are evaluated quantitatively based on the comparison with "Basic Frame". After that, the proposed prediction formula is contrasted with the time-history response analyses.

For the purpose of improving redundancy, authors propose a structural system (Fail Safe System) that gives a frame that acts as one with the building after beam plasticization is installed in a building designed to withstand assumed seismic motion, and new horizontal rigidity is added to the story where the horizontal rigidity of the story is greatly reduced. The effectiveness of this structural system is verified by seismic response analysis. If the proposed system is effective in reducing the response, it will be possible to secure the seismic safety of the building even in unexpected earthquakes, and it will be a structural system with improved redundancy.

As a result of seismic response analysis to excessive input seismic motion, it was shown that the deformation concentration phenomenon of the specific layer was suppressed and there was a large response reduction effect. In addition, we showed the realistic possibility of connecting the attached structural frame to the building.

The objective of this study is to examine the validity of the effective-length factors of columns in a single-story and two-story with three-span, five-span or infinite-span frames calculated by using the stability index (SI) method. Stability index is the ratio of PΔ moment to story-moment and related to the buckling strength. There are 3 types of analytical models which are frames with pinned-base, fixed-base and bottom beams and parameters are stiffness of beams and perimeter columns. The effective length factors obtained by the SI method is compared to accurate ones obtained by the buckling slope deflection method and the accuracy of the SI method is examined. The effect of the difference of the type of frames and analytical parameters on the effective length factor of columns and accuracy of the SI method are shown.