配筋砌块砌体短肢剪力墙恢复力模型

通过18片足尺全灌芯配筋砌块砌体短肢剪力墙低周往复荷载试验，研究了在压弯剪复合受力下墙体的抗震性能、刚度衰减方程以及恢复力模型。选取截面厚度包含190、240 mm和290 mm共3种块型的墙体，基于试验得到墙体骨架曲线，并计算得到归一化骨架曲线，简化为带下降段的三折线模型。通过计算得到模型中各阶段刚度比，用于确定骨架曲线的特征点。针对各次试验的刚度进行回归分析，得到满足指数衰减规律的刚度方程，据此提出了一种适用于配筋砌块砌体短肢剪力墙的滞回规则，并根据骨架曲线的各特征点，模拟了各次试验的滞回曲线。研究结果表明：模拟曲线能较好地反映配筋砌块砌体短肢剪力墙的“捏拢”现象，此恢复力模型可用于地震作用下配筋砌块砌体短肢剪力墙的非线性动力反应分析。

Restoring force model for reinforced block masonry short-leg shear walls

This paper intends to investigate the seismic performance of the reinforced-block masonry short-leg shear walls under the combined action of compression, bending and shear. Specifically,the stiffness degradation equation and the restoring force model were systematically studied according to tests of 18 full-scale fully grouted sample models subjected to low cyclic reversed lateral loading. The masonry block used to build these walls included three different cross-section widths, i.e.190 mm, 240 mm and 290 mm. The skeleton curves of walls were extracted from the test records, and the normalized skeleton curve was accordingly obtained which comply with a tri-linear model with a descending segment. Then stiffness ratios were finally calculated which were used to determine characteristic points on the skeleton curves. The exponential decay law was assumed to be suitable to model the stiffness degradation after regression analyses on the test data. A hysteretic rule that can be applied to reinforced-block masonry short-leg shear walls is accordingly proposed, and then the hysteretic curves of tests were modeled with the aid of characteristic points on the skeleton curves. It is demonstrated that the simulated curves can reflect the pinching phenomenon of these reinforced-block masonry short-leg shear walls; furthermore, it can be used to analyze the non-linear dynamics response of such shear walls.