Stability law and Analysis of Subway Station Foundation Pits in karst Areas

Xueran Wu
College of Civil Engineering and Architecture, Dalian University, Dalian 116622, China

Abstract:

To address safety risks in subway station foundation pit construction in karst-rich soil, this study focuses on the Zelonghu Station of Dalian Metro Line 4. It examines the im-pact of karst cave size, position, and burial depth on foundation pit stability in karst areas with adjacent buildings. The study proposes adjusting internal support stiffness to mitigate karst cave effects. Results indicate that larger karst caves and increased distance from the cave to retaining piles lead to greater horizontal deformation and ground settlement. Deeply buried karst caves, especially at 13 meters, significantly impact foundation pit stability. Increasing internal support stiffness reduces retaining pile deformation, but the effect plateaus at a certain stiffness level.