罕遇地震作用下钢筋混凝土框架-剪力墙结构的耗能机制分析

为了确定钢筋混凝土框架 剪力墙结构在强震作用下的合理耗能机制，对多个结构算例进行多条强震记录作用下的弹塑性时程分析。通过分析总累积耗能在各类构件中的分配和各类构件耗能沿结构高度方向的分布模式，研究结构的典型耗能机制类型，讨论耗能机制与结构参数的关系，并对不同的耗能机制进行评价。结果表明，“强墙肢弱连梁”整体型耗能机制使结构具有良好的抗震性能，应作为结构耗能机制设计的目标，“强连梁弱墙肢”耗能机制则应予以避免；连梁与墙肢的相对刚度关系是影响结构耗能机制的关键因素，框架和剪力墙相对数量的改变则不会明显影响结构耗能机制。对具有小跨高比连梁的结构，建议采用连梁水平分缝措施引导结构形成“强墙肢弱连梁”耗能机制，并通过算例分析验证了该措施的有效性。

Study on energy dissipation mechanism of reinforced concrete frame-shear wall structure under rare earthquakes

In order to determine the reasonable structural energy dissipation mechanism under rare earthquakes, several reinforced concrete frame-shear wall structures were analyzed by elasto-plastic time-history analytical method under a series of strong earthquake records. Based on the energy distribution among different types of structural members and along the structural height, typical energy dissipation mechanisms were summarized and evaluated respectively. And also the influences of structural parameters on the energy dissipation mechanisms were discussed. The results show that that ‘strong wall pier-weak coupling beam’ mechanism, leading to good structural seismic performance, should be set as the objective of structural seismic design while the ‘strong coupling beam-weak wall pier’ mechanism should be avoided. It is also shown that energy dissipation mechanism is determined by the relative stiffness of coupling beam and wall pier in the shear wall rather than relative numbers of frame and shear wall in the whole structure. At last, the measure of setting horizontal gap in the coupling beam with small span-depth ratio is proposed to result in ‘strong wall pier-weak coupling beam’ mechanism in the structure. And the effectiveness of this measure is validated through a numerical example.