软土地区地铁车站结构的非线性地震反应分析

为了明确天津市软土地基对地铁车站的结构地震反应的影响规律,以天津市地铁3号线的昆明路站为工程背景,采用数值模拟分析的方法,研究了该地铁站的地震反应。通过建立二维平面有限元模型,分析了结构抗震薄弱环节及结构抗震性能的影响因素。研究结果表明:天津宁河波作用下结构中柱内力响应明显大于其他构件,且柱底连接处内力幅值最大,为结构抗震薄弱环节;周围土层的弹性模量及上覆土层厚度对结构抗震性能的影响更明显,而结构自身的等效弹性模量对结构抗震性能影响不明显。研究成果丰富了软土地区地铁车站抗震设计理论,对地铁车站的优化设计具有重要意义。

Analysis of the Nonlinear Earthquake Responses of Subway Station in Soft Soil

To study how the soft soil affects the earthquake response of subway station, we used the finite-element method to model the practical engineering on the background of station Kunming Road station in Tianjin subway system. The two-dimension plane model is applied to create the finite element model foranalyzing the weak part in the seismic design and the influence factors of structural seismic behavior. Our results show that the response of middle column significantly greater than other members, especially, at column base. So the column base of middle column is regarded as the weak part in this structure. The effects of the elasticity modulus of the underground soil and the thickness of the overlaying soil on the structural seismic behavior are more obvious than the elasticity modulus of itself. Our research has enriched the theory of seismic design about the subway station in soft soil area, and is of great significance for section optimization of subway station.