Recently, seismically isolated buildings are required to secure a safety margin against extreme ground motion. The hardening characteristics of members used in seismic isolation layer may suppress excessive displacement of the seismic isolation layer. In this paper, the influence of the hardening characteristics on the seismic response characteristics is investigated. Furthermore, the prediction method for the maximum displacement of the isolation layer is derived based on momentary input energy.

In this study, by referring to the detailed evaluations for full-scale shaking table tests for wooden houses conducted in E-Defense in the past, a loss cost assessment for typical wooden houses is developed using a probabilistic evaluation method. In the seismic grade 1, structural components always had the highest loss, while in seismic grade 3, the loss of acceleration-dependent nonstructural components and household goods increased. When the seismic resistance grade higher, the increase in repair costs for acceleration-dependent nonstructural components and household goods was roughly equivalent to the decrease in repair costs for structures and deformation-dependent nonstructural components.

The characterized source model (0.2–10 Hz) composed of strong motion generation areas (SMGAs) of the 2024 M_J7.6 Noto Peninsula earthquake was estimated using the empirical Green’s function method introducing the simulated annealing method. All nine SMGAs were located deeper than 4 km from the surface. The SMGA with the largest short-period spectral level A was located on the northeastern fault with the opposite dip direction from the other faults. The A of total SMGAs was slightly larger than the previous scaling models and four Mw ≧ 7.4 crustal earthquakes outside Japan.

This paper proposes a seismic design method using optimization for super high-rise building with dampers. The method involves four steps:

1) Specifying frame stiffness distribution and natural period by optimizing the elastic response of moment frame to Lv1 seismic motion.

2) Specifying frame energy absorption performance by optimizing the elastic-plastic response of moment frame to Lv2 seismic motion.

3) With step 1) and 2) result, specifying damping device placement using placement optimization.

4) Based on step 3), specifying the member section using section optimization.

The method’s effectiveness is demonstrated by the result of analyzing a 100-meter-high building with oil dampers.

The authors previously presented an elasto-plastic analytical method of concrete-filled steel tubular (CFT) columns in consideration of fluctuation of axial force. In this paper, we conducted a seismic response analysis and an incremental loading analysis of a 40-story plane frame in which CFT columns are used. We compared the results between the proposed analysis model and a conventional one. In the results, the proposed model could simulate the elasto-plastic behavior of CFT columns more precisely. We show effectiveness of this analytical method for structural design of high-rise buildings.

Examining the ground’s deformation characteristics is valuable in assessing the impact of horizontal resistance of piles. In this study, horizontal pile loading experiments in a centrifugal 50G field and PIV were conducted for dense and loose sandy ground. Two types of experiments were conducted: one to observe the ground surface and another to observe the ground section. The size of the three-dimensional deformation area of ground in front of a pile at each loading stage was analyzed, and the results indicated that the horizontal resistance of a pile is related to the size of the deformation area of the ground.

This paper describes the construction methods and applications of cast-in-place concrete piles invented in Europe and the United States during the dawn and early Showa Period when they were introduced to Japan. Compressol piles were first introduced to Japan. Simplex piles, Raymond piles, Pedestal piles, and Franki piles were subsequently introduced. Pedestal piles were improved in the U.S., and further improvements were made in Japan. The Tanaka-style concrete pile was also invented and has been applied to many buildings. These piles are still supporting many historical buildings more than 100 years.

This study proposes a structural system and analysis model of passive controlled shear wall for mid-rise wooden construction consist of cross laminated timber and high damping rubber damper considering wood-appearance and construction efficiency. In this paper, to verify the validity of the proposed analysis model and the effectiveness of the shear wall, dynamic and static cyclic loading tests of full scaled shear wall specimens were conducted. Test results were simulated by analysis model using elastic-plastic pushover analysis. As a result, it was confirmed that the shear wall designed by proposed analysis model demonstrated its target performance.

Based on the experimental results of beams and columns, we have developed a new method for analyzing the response of RC high-rise buildings to severe wind forces repeated thousands of times. Main conclusions are as follows

1. In wind analysis, it is important to safely evaluate the hysteresis energy absorbed by beams, and a semi-nonlinear elastic slip model that takes into account the degradation characteristics of longitudinal reinforcement before yielding has proved useful.

2. It is important to evaluate the MN strength of columns using the column concrete strength reduced according to the target number of cycles.

Post-installed anchors are used to repair and strengthen existing concrete structures. Recently, RC structures damaged by earthquakes are used for a long time. Therefore, in this study, we investigated the bond strength of the post-installed anchor bonded to the RC beams before and after shear loading tests, and to crack-repaired RC beam. The bond strength was reduced by about 20 % for Damage II and about 30 % for Damage III compared to Non-Damage. In addition, the bond strength with crack-repair increased by up to 107 % compared to it without crack-repair.

The objective of this study is to present a new high precision formula for effective length factor of column in unbraced symmetrical frame. The analytical model is a portal frame which gives the same buckling equation for a sub-assemblage frame. The formula is derived by equating the total complementary energy and external work of axial compression force. Although there are limitations to the range of G factors, it is shown that a relative error from the correct value ranges from -0.065%～0.26%. Moreover, an example is given and compared to precise result.

This study investigates seismic response characteristics of a high-rise RC building with the composite foundation of wall and pile group. The building under investigation has maintained a dense, long-term array of strong-motion observations for over 25 years, including data during the 2011 Great East Japan earthquake. Simulation analyses with input motions in the NS and EW directions are performed. The effective input motion is evaluated from seismic records, and axisymmetric FEM analyses are performed for several cases with the foundation type as a parameter, and influences of foundation types on structural responses are discussed.