立交桥与地铁车站共站位条件下施工顺序对车站变形及受力的影响

为了解立交桥与地铁车站共站位条件下地铁车站在施工全过程中的力学特性,探索站桥施工顺序对地铁车站结构变形及受力的影响。通过拟设标准工程案例,借助有限元软件建立较为精细的三维模型,明确不同施工顺序下车站结构力学特性的差异。研究结果表明:先桥后站施工车站楼板竖向位移在每一跨内均表现为梁柱支座大跨中小,整体呈弓形的变化趋势,而先站后桥施工车站楼板位移表现为不同规律;先站后桥施工引起车站顶板及中板竖向位移较先桥后站有一定程度的升高,且中板增幅较顶板增幅大。站桥施工顺序对车站楼板横向弯矩影响较大,最大达到92.15%,发生在顶板侧墙处;纵向弯矩最大差异为55.05%,发生在顶板位置。先桥后站施工钢管柱水平位移及柱端弯矩大于钢筋混凝土柱,而先站后桥施工表现恰好相反。两种施工顺序下钢管柱与钢筋混凝土柱的轴力相差不大,最大的差异发生在钢管柱位置,仅为8.53%。

Effects of Construction Sequence of Overpass and Metro Station in the Same Location on Deformation and Stress of the Subway Station

In order to study the mechanical characteristics of subway station built jointly with the upper viaduct in the same location,and to understand the corresponding influence of stress and deformation induced by construction sequence,this paper,based on the standard project,uses the finite element software to establish a more precise three-dimensional model to determine the discrepancy of station structure mechanical performances subject to different construction sequences. The study shows that when the viaduct is built before the subway station,the vertical displacement of each span at the station floor is comparatively larger at the supports and literally small at the middle span,like a bow along with the length on the floor. In contrast,when the subway station is constructed before the upper viaduct,the vertical displacement of the station floor shows different changing pattern: first,due to the transition of construction sequence,both the displacement of roof and middle plate increase and the latter increases more significantly; second,the transverse bending moment of the station floor is significantly influenced by the construction sequence,and the maximum difference reaches 92. 15% at the position of the side wall roof; the longitudinal maximum difference is 55. 05% in the roof. Besides,the lateral displacement and bending moment of the steel tubular column is larger than that of the concrete column when the viaduct is built first, and the opposite is true when the subway station is constructed first. The two construction orders make no obvious difference in axial force of both the steel pipecolumn and the concrete column,and the maximum difference is only 8. 53% at the steel pipe column.