基于变形控制的超大直径深基坑双圆环支撑和高效开挖施工技术

深大基坑采用圆环支撑,一方面可以为基坑土方大开挖创造有利条件,但另一方面圆环支撑对基坑分块、对称、均衡开挖要求严格,变形控制难度大.结合天津陆家嘴广场基坑工程实际案例,着重介绍了在周边复杂环境与较高进度要求下,充分利用圆环支撑有利条件,以确保周边环境安全为前提,采取相应措施进一步提高基坑开挖效率.

Construction Technology of Double-Ring Support for Super Large Diameter and Deep Foundation Pit and Efficient Excavation Based on Deformation Control

On one hand, the deep foundation pit with ring support can create favorable conditions for its large excavation, but on the other hand, ring support do have a strict demand on pit block, symmetry and balanced excavation, therefore, the deformation control is difficult. Taking the Tianjin Lujiazui Square Project excavation engineering as an example, the paper introduces how to make the full use of the favorable benefits of the ring support under the conditions of the complicated environment and the strict progress requirement, to improve the efficiency of excavation by proper measures under the premise of the safety of the surrounding environment.