Research On Key Techniques Of Control Of Surface Settlement Due To EPB Shield Construction Of Line 1 In Nanchang

Earth pressure balance shield can adapt to a wide range of environments and strata, It’s widely used in urban subway construction. Concealment, unforeseeable and complexity is the basic characteristic of urban subway construction, the subway construction accident occurs frequently. Statistics show that surface settlement is one of the main factors of shield construction. The research of control of surface settlement has positive significance.Based on Nanchang Metro Line 1, this paper analyzes the main factors causing Surface Settlement of Nanchang water rich sand stratum, numerical simulation of shield tunnel construction by using FLAC3 D software, forming a research line of predicting surface settlement and identifying risk control key points, and proposed the key techniques of control of surface settlement due to EPB shield construction, this techniques was used to crossing the old stone arch bridge of Nanchang Metro Line 1, the maximum surface settlement is 5.6mm after the shield passes, the practicability and feasibility of this method has been proved through practical project, It can provide guidance for similar engineering construction.