The Launching Technique for Shield-Driven Tunnel with an Under-Pressure Soil-Chamber in Soft Layers

Abstract

In order to improving the launching technique in soft layer, the paper proposed the soil-chamber under pressure on the launching technique basing on engineering practices. The main principle is: using the earth pressure equilibrium, grouting the filling material when the Shield launching, establishing the active earth pressure ahead of time, which makes in advance the action pressure supports to the coarse sand cross section, that prevents from the water and soil spouting effectively. Because the active earth pressure, enhance the initial sending safety coefficient, and shorten the reinforcement length of the initial launching, and decrease the initial launching cost.