基于增量动力地震易损性分析的高层结构抗震加固研究

由于承重结构构件分布不均匀,导致高层建筑框架承重构件间的距离不相等。在地震时,这种不规则分布可能引起加速度共振效应,从而导致建筑失稳。为此,以地震动强度、地震动速度峰值、最大层间位移角为参数指标,分析高层建筑的极限状态,提出基于增量动力地震易损性分析的高层结构抗震加固研究。以某实际工程为试验对象,运用ABAQUS软件构造高层建筑框架结构三维模型,选取多条地震波以及符合场地条件的地震动记录进行验证,绘制地震易损性曲线。结果表明:在高层建筑框架结构中安装阻尼器,可增强结构中各构件的承载力,改善高层建筑抗震性能;增加钢板厚度可提高结构抗震水平,降低极限状态下框架结构IO、LS与CP的超越概率;提高混凝土强度,可改善框架结构抗倒塌性能。高层结构完成抗震加固后,抗震能力由0.91提升至1.01。由此证明,以增量动力分析得到的结构易损性为基础,对建筑易损性较大的地方进行加固、完善,能够改善高层建筑框架结构地震易损性,减少地震灾害损失。

Seismic strengthening of high-rise buildings based on the seismic vulnerability from incremental dynamic analysis

Because load-bearing structural members are unevenly distributed in high-rise buildings, the distance between these members is unequal. This irregular distribution may cause the acceleration resonance effect during earthquakes, resulting in building instability. In this paper, the seismic retrofit of high-rise structures was studied on the basis of incremental dynamic analysis using parameters such as seismic intensity, peak ground velocity, and the maximum story drift ratio. A 3D model of an actual high-rise building was constructed using ABAQUS software, and multiple seismic waves and ground motion records were selected to validate the seismic vulnerability curve. The results show that installing dampers in the high-rise structure improves the bearing capacity of components and enhances the seismic performance of the building. Increasing the thickness of steel plates improves the seismic resistance of the structure and reduces the exceeding probability of IO, LS, and CP of the frame structure in the limit state. Increasing the strength of concrete improves the anticollapse performance of the frame structure. After seismic retrofitting, the seismic capacity of the high-rise structure improves from 0.91 to 1.01. This study proves that strengthening and perfecting the vulnerable areas of buildings based on a seismic vulnerability analysis improves the seismic vulnerability of high-rise structures and reduces the loss of earthquake disasters.