Deformation Control for Foundation Pit Segmented Construction Adjacent to Operational High-speed Railway Lines

Abstract

Objective Limited land use resource and arrangement adjacent to operational high-speed railway lines pose significant challenges to some city foundation pit constructions and the railway operational safety. To reasonably predict and control the foundation pit and adjacent high-speed railway subgrade deformations, it is necessary to conduct deformation control studies on foundation pit construction. Method Based on an open-cut foundation pit near a high-speed railway subgrade in Shanghai, Plaxis 3D software is used to analyze the impact of different foundation pit segmented construction lengths on the enclosure structure and adjacent high-speed railway subgrade, and the deformation control effectiveness of segmented construction on foundation pit itself and adjacent high-speed railway subgrade is analyzed according to field-measured data. Result & Conclusion Segmented construction can effectively reduce the deformation of both the foundation pit enclosure structure and the existing high-speed railway subgrade. The shorter the segmented length is, the smaller the deformation of foundation pit and existing high-speed railway subgrade, and the more evident inhibition corner effect formed by foundation pit segmentation walls has on enclosure structure deformation. Based on field measurement data, with a segmented length of 30 m, both of the foundation pit enclosure structure deformation and the high-speed railway subgrade vertical deformation remain in standard limits; however, the subgrade horizontal deformation exceeds the limit requirements.

Keywords

• foundation pit
• segmented construction
• deformation control
• operational high-speed railway line