关键词: 输水隧洞;双护盾TBM;施工效率;地质因素;兰州市水源地建设工程;

Abstract: Taking the construction of Lanzhou Water Source Project as a background, which uses double shield TBM for tunneling, we analyze the effects of geological factors on TBM tunneling efficiency through on-site investigation and data statistics and propose countermeasures for each geological factor.The geological factors include uniaxial compressive strength of rock, rock mass integrity, quartz content of rock, ground stress, and groundwater.The results show that when the uniaxial compressive strength(Rc) of rock is between 50～80 MPa, the TBM advancing rate(AR) reaches over 30 m in a day.When Rc is below 50 MPa, AR decreases with decreasing strength.When Rc is above 80 MPa, TBM tunneling speed decreases with increasing Rc.When the rock mass integrity coefficient(Kv) is between 0.40～0.60,AR reaches the highest.When Kv is greater than 0.60,AR decreases with increasing Kv,and when Kv is less than 0.4,AR decreases with decreasing Kv.The lower the quartz content of the rock, the lower the ground stress level, and the less groundwater, the more favorable it is for TBM tunneling.The research results can provide reference for TBM geological suitability evaluation and construction methods for similar projects.

Key words: water conveyance tunnel; double shield TBM; construction efficiency; geological factor; Lanzhou Water Source Project;