复杂敏感环境下的深大基坑设计与实践

摘要

复杂敏感环境下的深大基坑开挖通常存在较大的风险,合理选择基坑设计方案是保证基坑安全的前提.以具有地质条件复杂、周边环境敏感和基坑深大特点的2个基坑为例,综合考虑地质、水文、周边环境、基坑形状和施工便利性等诸多因素,经过多组分析计算,采取具有针对性的基坑围护结构形式、支撑布置形式、地下水处理措施和地铁自动化监测措施等,实现了基坑安全和周边环境的安全,并对基坑和周边环境监测结果进行了分析总结.结果表明,对复杂敏感环境下的深大基坑设计时,要对周边环境有充足的认识,并进行详细的计算,对有偏差的计算结果进行重点分析,对重要的风险源及时采取针对性的处理措施.%Many risks would be encountered during excavation of deep and large-scale foundation pit in complex and sensitive environment, consequently, rational design scheme is very important.In view of 2 deep and large-scale foundation pits in complex and sensitive environment, a series of technologies, i.e., retaining structure mode, support arrangement mode, groundwater treatment and automatized metro monitoring, are taken to guarantee the safety of foundation pit and surrounding environment with consideration of geology, hydrology, surrounding environment, shape of foundation pit and convenience.The monitoring results of foundation pit and surrounding environment are analyzed, and the analytical results show that the surrounding environment of deep and large-scale foundation pit in complex and sensitive environment should be well recognized, detailed calculation should be carried out, the calculation deviation should be calculated with emphasis, and corresponding countermeasures should be adopted for important risk source timely.