无柱加腋地铁车站土-结构模型振动台试验

以南宁地铁5号线金桥站为工程背景,根据模拟地震振动台试验的相似性理论,考虑地铁车站结构与土的材料性能、几何特性以及模型结构动力试验的相似关系等,设计制作了用于模拟地震振动台试验的无柱加腋地铁车站模型结构和试验用模型箱。选取El Centro地震波、Taft地震波和南宁人工地震波,同时考虑地铁车站结构上覆土厚度等参数的变化,进行了多种工况下的模拟地震振动台试验,研究了考虑地铁车站土-结构相互作用的无柱加腋地铁车站模型结构的地震响应特点和主要变化规律,分析了上覆土厚度对模型结构动力响应的影响,考察了结构抗震的薄弱部位和主要损伤区域。采用ABAQUS有限元软件建立考虑地铁车站土-结构相互作用的三维空间有限元模型,进行了相应工况下的模拟地震有限元时程分析,并与振动台试验结果进行了比较。结果表明:有限元模拟结果与振动台试验结果吻合较好,说明建立的有限元模型和分析方法可靠有效; 3种地震波下模型结构的主要地震响应特点基本相同,其加速度响应和位移响应都随输入峰值加速度的增大而增加; 上覆土厚度是影响车站模型结构加速度响应的重要因素,当上覆土厚度较薄时,车站模型结构的位移响应较大; 模型结构的侧墙与底板、中板连接的加腋处是开裂和损伤最严重的区域,侧墙裂缝呈竖向发展,并出现多道连续裂缝,应引起重视。

Shaking Table Test of Soil-structural Model of Non-column Haunched Metro Station

Taking the Jinqiao Station in Nanning Metro Line 5 as the engineering background, based on the similarity theory of the simulated seismic shaking table test, premeditating the material properties and geometric characteristics of the metro station structure and soil and the similar relationship of the dynamic test of model structure, a non-column haunched metro station structure and test model box were designed and fabricated. Then, selecting the El Centro seismic wave, Taft seismic wave and Nanning artificial seismic wave, and considering the variation of the thickness of the overlying soil on the metro station structure, the simulated seismic shaking table tests under various working conditions were carried out. The seismic response characteristics and main variation laws of the non-column haunched metro station were studied, and the influence of the thickness of the overlying soil on the model structure was analyzed. The weak parts of the structure and the main damage area were investigated. A three-dimensional space finite element model considering the interaction between soil and structure of metro station was established by ABAQUS finite element software, and the time history analysis of simulated earthquake under corresponding working conditions was carried out, then the results were compared with the shaking table test results. The results show that the finite element simulation results are in good agreement with the shaking table test results, and the finite element model and analysis method established are reliable and effective; the main seismic response characteristics of the model structure under three kinds of seismic waves are basically the same, and the acceleration response and displacement response increase with the increase of the input peak acceleration. The thickness of the overburden soil affects the acceleration response of the station model structure. When the thickness of the overlying soil is thin, the displacement response of the station model structure is relatively large, the most serious area of the crack and damage is the haunch where the side wall of the model structure is connected with the base plate and the middle plate, and the cracks on side wall develop vertically and multiple continuous cracks appear, which should be paid attention to.