Analysis on ground settlement induced by shield tunneling undercrossing railways and tall buildings

摘要

It is very important to keep railways and tall buildings safe when tunnels are excavated undercrossing them. The horizontal distance between the tall building and its right tunnel is only 9.1 m, and the vertical distance between the railway and its left tunnel is 11.1m. In order to assess the ground settlement caused by shield tunneling, numerical simulation is made by FLAC3D. The parametric on the reinforcement area of soils around tunnels, the earth pressure, shield machine driving forces and grouting pressure were studied to decide the appropriate range in the process of shield tunneling construction. At the same time, the settlement of tall building, the ground settlement of railways, the culvert displacement and the convergences of the tunnels were monitored in-situ. The monitoring results and the numerical results coincide very well with each other. The reinforcement of soils around the tunnels was successfully decreased the ground settlement of railways and tall buildings. The case can provide reference for shield tunneling undercrossing all kinds of structures.