中大型基坑工程在应用中心岛方案并施工有限跨结构的过程中会因深大基坑分区开挖工况所限,支撑体系产生不平衡土压力,并以水平侧力的形式通过支撑传递到坑内。对此设计了将水平侧力施加到地下室已建结构体系上,由地下结构的梁板柱和工程桩共同承担的方案。此情况下在近受力端的结构构件将表现出较大的内力和结构变形。因而在水平侧力较大的条件下需要提出切实有效的加强措施提高受力端结构刚度,并将整体受力变形控制在合理范围内。本文以实际工程项目为背景,通过三维数值分析对有限跨结构在深大基坑中的抗水平侧力进行了模拟和讨论,并比选了几种结构加强方案。结果表明,该体系在受力端设计斜撑压杆加强能够有效提高结构抗水平侧力能力。

During the process of implementing central island scheme and constructing multi-span structures in large foundation pit projects, due to the limited construction conditions, the support system generates unbalanced soil pressure, which is transmitted inwards through the support in terms of horizontal lateral force. It has been designed to apply horizontal lateral forces to the existing structural system of the basement, which was jointly undertaken by the beams, columns, and engineering piles of the underground structure. In this case, the structural components near the load-bearing end is expected to exhibit significant internal forces and structural deformation. Therefore, under the condition of large horizontal lateral forces, it is necessary to propose practical and effective strengthening measures to improve the stiffness of the load-bearing end structure and control the deformation within a reasonable range. Taking an engineering project as the background, simulates and discusses the horizontal lateral force resistance of multi-span structures in deep and large foundation pits through three-dimensional numerical analysis. Several structural strengthening schemes are compared and selected. The results show that the design of slant support compression bar strengthening at the loading end of the system can effectively improve overall ability to resist horizontal lateral force.