Ground Treatment and its Application in Shallow Subway Tunnel Crossing Urban River by Shield Tunneling Method

Abstract

On the basis of the geological and environmental conditions of surrounding rock around a shallow subway tunnel used to cross a river in Chengdu subway line one, the ground treatment technique such as uplift piles, cast-in-place reinforced concrete slabs and site grouting have been summarized in the paper. The riverbed above shallow shield tunnel is reinforced with covering slabs and uplift piles; meanwhile, the surrounding rock is reinforced with cement and sodium silicate grout by high pressure grouting method conducted inside the tunnel. The practice of the scenario presented in the paper turns out to be a great success and shows that the treatment technique can be used to guide the design and construction of ground reinforcement for shallow tunnel used to cross urban rivers in subway lines by shield tunneling method under similar conditions.