关键词: 紧邻隧道深基坑, 基坑分区设计, 地铁保护, 实测分析

Abstract: This article, based on a project in Zhangjiang, Shanghai, introduces the design concept and key technologies of excavations adjacent to metro tunnels in soft soil areas, and analyzes the impact of the excavation on metro tunnels. The project is in the core development zone of Zhangjiang area in Shanghai. There are excavations under the construction simultaneously with the project on the east, west and north sides. The north side of the pit is adjacent to the tunnel of Metro Line No. 13. The design of the excavation supporting structure not only needs to fully consider the protection of roads, municipal pipelines, and existing tunnels but also needs to avoid the impact of the overlapping effects of largearea excavation groups on the tunnel. Through the reasonable zoning design, the project not only meets the overall construction needs of the main building structure but also shortens the construction period by coordinating the excavation sequence of adjacent blocks and dividing narrow strip excavations adjacent to the tunnel to reduce the impact of the large-area unloading on the tunnel. Site measurements show that the excavation construction’s impact on the metro tunnel is effectively controlled by measures such as reasonable selection of enclosing structures, internal reinforcement, automatic axial force servo compensation system for steel supports, symmetric balanced excavation, steel support clamping and dismantling and steel exchange support. This study provides a reference for similar engineering projects.

Key words: Deep Excavation Adjacent to Tunnels, Zoning Design, Protection Methods for the Tunnel, Field Measurement Analysis