Attitude Control of Large Cross- Section Box jacked in Pipe-Roof in Soft SoiAttitude Control of Large Cross- Section Bol Layer

摘要

The tunnel of Shanghai center ring under Beihong road is the first case of pipe-roof engineering without reinforcing the inner soft soil in the world as well as in mainland. The pipe-roof with box cross-section is made of 80 steel pipes of which the diameters are all 970mm connected by interlocks. Dimensions of the culvert box are 34.2m(width) × 7.85m(height)×126m (length). The grid shield maintains stability of the excavation surface by extruding soil. Based on the mechanical analysis, guiding pies combined with computer fluid-pressure simultaneous jacking system is adopted and soil excavation within the grids is practiced to ensure the horizontal and vertical deviation of the large cross section culvert box within an allowable range. In this paper, the horizontal and vertical attitude control method of the culvert box is introduced in detail, and this method can be a reference for similar projects.