Mechanical response and parametric analysis of a deep excavation structure overlying an existing subway station: A case study of the Beijing subway station expansion

The existing Beijing Pingguoyuan Subway Station was extended through a extension project. excavation for the located directly above station. Complex interactions exist between structure and retaining pile wall of excavation. Based on this project, three-dimensional finite element models were established to investigate mechanical characteristics embedded non-embedded walls. A parametric analysis performed both types stress deformation walls structures analyzed. results show that when bottom are connected structure, uplift is essentially constant; however, maximum displacement increased by approximately 2.7 times, bending moment reduced 57.1% connection condition. As distance station increases, increases linearly, whereas soil exhibits non-linear increasing trend. as inner force decreases. When greater than 4.7 m, remains unchanged. effect depth mainly observed in lower part pile. decreases 16.9%, decreases, negative increases. key contribution research provide prediction method behaviors expansion findings from study also industry practitioners with comprehensive guide regarding specific applications construction technology deep overlying an subway