Short-period ground motions from earthquakes are calculated by semi-empirical methods such as the empirical Green’s function method or the stochastic Green’s function method. In this review paper, I summarized source models developed for reproducing and predicting ground motions in the theoretical methods at first, and reviewed the source models applied to reproducing and predicting ground motions in the empirical Green’s function method in these about 40 years. Finally, I showed some issues to be solved about source modeling in order to predict accurate short-period motions in the near-fault regions.
This study focuses on the RC secondary flat walls used as exterior/partition walls in typical residential buildings in Japan and proposes a new rebar arrangement for the walls, which removes wall vertical rebar anchorage to reduce earthquake damage. A series of cyclic loading tests of four full-scale RC secondary flat wall specimens was performed with two experimental parameters: presence or absence of the wall vertical rebar anchorage and quantity of confining reinforcement in the wall ends. Consequently, the performance limits were improved by removing the wall vertical rebar anchorage and increasing the quantity of confining reinforcement in the wall ends.
This paper conducted finite element analysis of the beam with lateral bracings subjected to cyclic loading and investigated deformation capacity. The following were obtained.
1) There was obvious correlation between the deformation capacity and Λcmax; Λcmax is the index with consideration for slenderness ratio and width-thickness ratio. Functions of deformation capacity were proposed.
2) Characteristics of three deformation capacity indexes were shown: plastic deformation magnification R, cumulative plastic rotation angle Σθp, and maximum plastic rotation angle Θpmax. Θpmax is the most suitable index of deformation capacity, because it is insensitive to material strength and loading history.
Numerical analysis, which considers the material and geometrical nonlinearity, was conducted to understand the structural behavior of the steel beam-column in this study. Axial force, member length, cross-sectional shape, and end moment ratio were selected as the parameters to gather sufficient data. As a result, the design formula that can be used to guaranty the beam-columns ductility was proposed. Moreover, quantitative formula to predict the plastic deformation capacity was proposed. Finally, the ultimate limit state determined by local buckling or in-plane instability was studied; the border where the mode will change was verified with the existing test results.