关键词: 隧道, 软弱富水地层, 超深竖井, 大直径泥水盾构, 快速接收

Abstract: Four largediameter slurry shields should be received in an ultradeep shaft in waterrich and weak strata (clay, silt, and siltyfine sand). Consequently, Ushaped plain diaphragm wall + ultradeep triaxial mixing pile + Rodin jet pile ultrahigh pressure jet grouting is used to consolidate the ground, and the dewatering well is adopted to improve the overall stability and waterstop effect of end soil of the receiving shaft and realize fast shield receiving. Further, the gyroscope orientation and cast point hole for penetration measurement are adopted to ensure the accuracy of shield receiving and provide a basis for fast and precise positioning and installation of the receiving base. Hydraulic drilling and wiresaw cutting are used to break the concrete door of Wangjing tunnel, which significantly improves the door breaking efficiency. The steel ring of the tunnel is installed with double wire brushes as the sealing of the receiving tunnel, which prevents sand and water from gushing effectively when the door is broken, ensures the safety of shield receiving, reduces the installation and removal of the last ring segment, and further rapids the shield receiving. By adopting the abovementioned key techniques and scientifically organizing and coordinating the receiving and dismantling sequence of the four shields, the fast receiving of the four largediameter shields used in Wangjing tunnel of BeijingShenyang railway is realized.

Key words: tunnel, watery and weak stratum, ultradeep shaft, largediameter slurry shield, fast receiving