高强混凝土剪力墙性能指标研究

在基于性能的抗震设计中,结构的性能指标是一个必需的重要参数。基于21个剪跨比分别为2.1,1.5和1.0的矩形截面、带端柱和型钢高强混凝土剪力墙的抗震性能试验资料,分析了各种剪力墙的破坏形态。将剪力墙的性能划分为三个水平,即:使用良好、生命安全和防止倒塌,分别给出了剪力墙发生弯曲(弯曲剪切)破坏和剪切破坏时三性能水平的失效判别标准,确定了三性能水平极限状态时各剪力墙的位移角平均值。分析结果表明,高强混凝土剪力墙在三性能水平的位移角分布均基本符合正态分布,其在生命安全和防止倒塌性能水平位移角平均值与FEMA273的建议值很接近,而我国抗震规范建议的弹性位移角限值和弹塑性位移角限值的保证率系数分别为2.18和1.58。根据试验结果,提出了高强混凝土剪力墙结构三性能水平具有95%保证率的位移角限值。

Research on the performance index of high-strength concrete shear walls

In the performance-based seismic design,performance index of the structure is a necessary and important parameter.According to the seismic performance test data of 21 high-strength concrete shear walls with rectangular cross-section,boundary column and steel which shear span ratio are 2.1,1.5 and 1.0,various failure modes of shear walls are analyzed.The performance of shear walls is divided into three levels,that is namely serviceability,life-safety and collapse protection,and the failure criterions of the three performance levels are presented respectively when flexural(flexural-shear) failure and shear failure are occurred on shear walls.Meanwhile,the mean values of all the shear wall drift ratios for ultimate state of the three performance levels are determined.The analysis results show that the drift ratio distribution of shear walls for three performance levels are basically consistent with normal distribution,and drift ratio mean values of life-safety and collapse protection performances are closed to the recommended values of FEMA273,while assurance factor of the elastic drift ratio and elastic-plastic drift ratio limit value for Chinese seismic code are 2.18 and 1.58 respectively.According to the experimental results,drift ratio limit value with 95% assurance factor for the three performance levels of shear wall structure are presented.