Abstract
To investigate the construction technology of tri-mode tunnel boring machines (TBMs) operating in TBM mode within full-face rock strata, this study takes the shield tunnel section project between Luogang Station and Shuixi Station on Guangzhou Metro Line 7 Phase II as the research background, and summarizes the TBM mode construction technology of tri-mode TBMs from four aspects: muck removal method, excavation parameter control, cutter management, and stabilizer application. The results indicate that: 1) In this project, the tri-mode TBM utilized button cutters for excavation, which resulted in lower consumption compared to disc cutters and reduced cutterhead torque; 2) The TBM mode of the tri-mode TBM employed dual-channel muck removal via slurry circulation and screw conveyor, which significantly reduced the probability of slurry pipe blockage and improved muck removal efficiency; 3) The installation of stabilizers and gripper shoes on the front and middle shields of the tri-mode TBM prevented shield rolling during tunneling in full-face hard rock formations while enhancing shield stability; 4) When excavating tunnels in full-face rock strata using the TBM mode of a tri-mode TBM, the cutterhead rotation speed was 3.0 r/min, the total thrust was approximately 15000 kN, the torque could be controlled at 1300 kN·m, and the advance rate was 8–12 mm/min.
Full Text
Tunneling Technology of Three-Mode Tunnel Boring Machine Under TBM Mode in Full-Section Hard Rock
Xie Wenda¹, Liang Hongbing¹, Chen Qiaosong¹, Guo Yongshun², Ma Jingzhe²
¹ Guangzhou Metro Engineering Consulting Co., Ltd., Guangzhou 510000, Guangdong, China
² China Railway Tunnel Group No. 3 Engineering Co., Ltd., Guangzhou 510530, Guangdong, China
Abstract
This study investigates the construction technology of three-mode tunnel boring machines (TBMs) operating in TBM mode within full-section rock strata, using the shield tunneling interval between Luogang Station and Shuixi Station on Guangzhou Metro Line 7 Phase II as the engineering background. The construction technology is systematically summarized from four key aspects: mucking methods, excavation parameter control, cutter management, and stabilizer application. The results demonstrate that: (1) The use of insert-type disc cutters on the three-mode TBM in this project resulted in lower cutter consumption and reduced cutterhead torque compared to smooth disc cutters; (2) The dual-channel mucking system utilizing both slurry circulation and screw conveyor in the TBM mode significantly decreased the likelihood of slurry pipe blockages and enhanced mucking efficiency; (3) The installation of stabilizers and gripper shoes on the front and middle shields effectively prevented shield rolling during excavation in full-section hard rock strata while improving shield stability; and (4) When employing the three-mode TBM in TBM mode for tunnel excavation in full-section rock strata, the operating parameters were: cutterhead speed of 3.0 r/min, total thrust of approximately 15,000 kN, torque maintained at 1,300 kN·m, and advance rate of 8–12 mm/min.
Keywords: rail transit; three-mode tunnel boring machine; hard rock section; excavation efficiency; full-section rock strata