深基坑混合支撑体系设计改进

摘要

通过美兰机场隧道加宽段和车站深基坑的工程实践,研究应用了上部钢筋混凝土支撑、中部锚索支撑、下部钢支撑的混合支撑体系。采用FLAC软件,对基坑的开挖过程进行模拟,研究车站深基坑混合支撑围护结构的内力与变形规律,分析影响基坑稳定的主要因素,完善和丰富该类围护结构内力与变形的计算理论,验证本工程施工方案的安全及经济可行性,为今后类似基坑的施工设计提供借鉴。%Based on the construction of tunnel widening and the station foundation pit for Meilan International Airport,the paper studies the application of the mixed-support system of the upper concrete support,the central anchor cable support and the lower steel support.FLAC software is adopted to simulate the excavation process of the pit so as to study the internal force and deformation law of mixed-support structure for station deep pit,analyze the main factors of affecting the stability of pit,improve and enrich of computational theory of internal forces and deformation for such support structure,and verify the safety and economic feasibility of the construction method in order to provide reference for similar foundation construction design in the future.