考虑多维地震作用的高耸钢筋混凝土烟囱结构易损性分析

发布时间：2019-01-30 15:48

【摘要】：竖向地震作用对高耸烟囱结构动力响应有不可忽略的影响。选用240m高的某钢筋混凝土烟囱作为研究对象,考虑结构损伤,通过有限元软件ABAQUS,采用复合壳单元建立相应的非线性有限元分析模型。为考虑地震动的不确定性,根据谱相容性原则,选择20条合理地震动记录,进行增量动力分析。输入的地震动分别为一维、二维、三维。分别以材料应变和地面峰值加速度作为结构地震需求参数和地震动强度参数,结合增量动力分析获得的结构地震响应,采用能力需求比模型的曲线拟合法计算易损性曲线。通过钢筋和混凝土的材料应变定义四个损伤状态限值,最终得到在不同维数地震动输入时高耸钢筋混凝土烟囱结构的地震易损性曲线和倒塌概率曲线。研究结果表明,考虑多维地震作用比只考虑一维地震作用时高耸烟囱的结构易损性和倒塌概率增大。
[Abstract]:Vertical seismic action has an important effect on the dynamic response of tall chimney structure. A reinforced concrete chimney with a height of 240 m was selected as the research object and the damage of the structure was considered. The nonlinear finite element analysis model was established by using the composite shell element with the finite element software ABAQUS,. In order to consider the uncertainty of ground motion, according to the principle of spectral compatibility, 20 reasonable records of ground motion are selected for incremental dynamic analysis. The input ground motion is one-dimensional, two-dimensional and three-dimensional. Taking material strain and ground peak acceleration as structural seismic demand parameters and ground motion intensity parameters, combined with the structural seismic response obtained by incremental dynamic analysis, the vulnerability curve was calculated by curve fitting method of capacity demand ratio model. Through the definition of four damage state limits by the material strain of steel bar and concrete, the seismic vulnerability curves and collapse probability curves of high-rise reinforced concrete chimney structures with different dimensions of ground motion input are obtained. The results show that the structural vulnerability and collapse probability of tall chimneys are increased when the multi-dimensional seismic action ratio is considered only for one-dimensional earthquakes.
【作者单位】：北京交通大学;
【基金】：国家自然科学基金面上项目(51478033,51178029)
【分类号】：TU311.3;TU375

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