关键词: 大断面矩形顶管, 地铁车站, 沉降控制, 推进参数, 新型止退系统, 减摩触变泥浆

Abstract: There is no relevant engineering experience of large crosssection rectangular pipe jacking method in  the construction of metro stations in urban core area. The Jing′an Temple station of line No.14 of Shanghai metro, the first large crosssection rectangular pipe jacking methodconstructed underground station in soft soil, is taken as an example, and the construction settlement control techniques of the east line tunnel including reasonable propulsion parameters, new antireaction system, new antifriction thixotropic mud and corresponding pressure injection technology are introduced in detail. The actual value of the soil pressure on the upper part of the soil camber is slightly higher than the set value, and the difference is controlled between 1.1% and 7.5%. The actual values of main parameters such as total thrust, main cutterhead torque, and propulsion speed are strictly controlled within the set value range. The retraction of the pipe is controlled within 35 mm by using new antireaction device. The new antifriction thixotropic mud can perfectly fill the gaps and reduce the friction between the soil and the pipe. The analytical results of measured surface deformation data show that during pipe jacking of east line, the maximum cumulative longitudinal settlement occurs at area 18 m above pipe, i.e. about 2 times of pipe jacking diameter, and the overall surface settlement is controlled between -15 mm and 5 mm.

Key words: large crosssection rectangular pipe jacking, metro station, settlement control, propulsion parameters, new anti-reaction system, anti-friction thixotropic mud