Analyzing the depth of a deep excavation considering the limit lateral displacement of adjacent tunnel

Abstract

The paper presents an analysis of the depth of a deep excavation considering the limit displacement of adjacent tunnels. This case study is a real project located in Ben Nghe, District 1, Ho Chi Minh City. The building has five basements with an excavation depth of 23 meters. The distance between excavation and Tunnel is 40 meters. The excavation progress is simulated by the finite element method (using Plaxis 2D software). The Hardening soil model is adopted to describe the behavior of soil. The back analysis is implemented to propose the suitable input parameters of soil model by comparing lateral displacements of retaining-wall from FEM results and measurement. Then, the Tunnel model is added with different distances to the excavation for analyzing the relationship between depth of the excavation and limit displacement of Tunnel. The results show that the limit depth of excavation is strongly reduced to satisfy the requirements of limit displacement of adjacent tunnel. Additionally, the limit distance between a deep excavation and an adjacent tunnel is 40 meters.