软土深基坑开挖变形特性及围护结构内力变化的试验研究

以宁波某典型软土深基坑工程为例,运用概率统计方法,对基坑开挖过程监测数据进行分析,得出一些有益规律。同时,结合理论反演分析,深入探讨了分步开挖条件下,围护结构变形特性及其内力变化规律,进一步分析了地表沉降与围护结构变形内在关系,并对工程影响范围等主要指标作了研究。研究结果表明:软土地质条件下围护结构变形不易控制,最大变形于开挖面位置,围护结构内力最大值随开挖深度增加而增大,开挖至底板标高附近时,其内力发挥达到最大值且增幅最大,处于最危险状态,应予以高度关注。

Experimental Research on Deformation Characteristics and Change Law of Internal Force Envelop Enclosure of Deep Foundation Pit in Soft Soil

Taking the typical soft soil deep foundation pit engineering in Ningbo for an example, the probabilistic method is adopted to analyze the monitoring data in the excavation process of deep foundation pit and get some beneficial conclusions.Meanwhile, combined with the inverse analysis of theory, the deformation characteristics and change law of internal force of enclosure structure under excavation by steps are further discussed.In addition, the internal relationship between ground settlement and deformation of enclosure structure is further analyzed and main indicators like the excavation influence scope are studied.The research results show that the enclosure structure deformation in soft soil geological condition cannot be easily controlled, and the biggest deformation of enclosure appears near the excavation face.The internal force of enclosure structure will increase with the excavation depth, and the biggest internal force and the biggest growing rate appear at the elevation of baseboard.This is the most dangerous state and needs high attention.