About the author:

China Railway 18th Bureau Group Fourth Engineering Co., Ltd., Tianjin 300500,China

Abstract:

The construction of urban underground integrated pipe gallery foundation excavation faceschallenges such as low soil strength and strict deformation control requirements. To clarify the deformationcontrol mechanism of the foundation excavation enclosure structure, an analysis was conducted on theSMW pile+concrete support+steel support combination enclosure structure. The influence of the insertionratio of enclosure piles, the number of support channels, and the spacing between supports was studied,and construction measures of parameter coupling optimization and dynamic control were proposed tocontrol the displacement of the pile top within the limit. The research results indicate that the horizontaland vertical displacement of the enclosure structure of the pipe gallery foundation excavation shows agradual increase, a steep increase, and a stable decline trend. The insertion ratio of enclosure pilesshould be controlled at 1.1~1.2, and the support spacing should be set at about 3m. The construction ofone concrete support and one steel support can meet the safety requirements. If necessary, two steelsupports can be added to better control the deformation of the enclosure structure.