Study on Restoring Characteristics of Reinforced Concrete Open-Section Shear Walls Subjected to Bi-directional Horizontal Force

U形或L形剪力墙是建筑结构中常见的抵抗地震侧力的剪力墙。在这类结构的分析中，开口墙通常被分解成单个平面构件，这些构件被假定只贡献在各自平面方向上有效的分离的平面墙体的面内刚度和强度。然而，为了评估空心墙在水平荷载作用下的行为，必须将其视为符合其整体结构特点的整体空心墙。在本研究项目中，为了获得建立此类墙体弹塑性力学模型的基础数据，进行了以下两系列试验：1)钢筋混凝土平面剪力墙在弯剪联合作用下的受弯性能试验；2)钢筋混凝土L形不等边截面剪力墙在双向水平力作用下的恢复特性试验。1)钢筋开始弯曲屈服前的平面剪力墙曲率分布可以近似用三次曲线表示，因此可以由墙基的曲率来估算抗弯变形。2)L形截面剪力墙双向极限抗弯强度可以由双向荷载平面上三种受弯破坏模式的计算值绘制成三角形来估算。

The shear walls with a U or L shaped section are commonly in building structures to resist the lateral forces imposed by earthqakes. In the analysis of such structures the open-section walls are usually disassembled to the single plane components which are assumed to contribute only in-plane stiffness and strength of separated plane walls effective in their own plane direction. However, in order to estimate the proper behaviors of open-section walls subjected to lateral forces, it must be treated as the integrated open-section walls conforming to their overall proper structural characteristics.In this research project, following two series of tests were carried out in order to obtain the basic data for preparing the elastic-plastic mechanical model of such walls;1) Tests for obtaining the data on flexural characteristics of reinforced concrete plane shear walls subjected to combined bending and shear.2) Tests for obtaining the data on restoring characteristics of reinforced concrete unequal-sided l-shaped section shear walls subjected to bi-directional horizontal force.The main results of this tests are as follows;1) The distribution of plane shear wall's curvature before reinforcing bar starting to yield by flexure can be nearly expressed by a cubic curve, so that fiexural deformation can be estimated from the curvature of wall base.2) The bi-directional ultimate bending strength of L-shaped section shear walls can be estimated from the triangle plotted the calculated value from three patterns of bending failure on a bi-directional loads plane.