Monitoring and Reinforcement Technology of Passing Weak and Broken Rock Strata for Tunnel Boring Machine

Abstract

The stability control of surrounding rock is a relatively important problem in tunnel boring machine (TBM) construction. The tunnel convergence deformation value was monitored in field while TBM passing weak and broken section of hydraulic tunnel. The correlation between tunnel convergence and surrounding rock stability is analyzed. The monitoring results show that: the characteristic of weak and broken Strata is closely correlated with some geological conditions, such as fault development, intrusive contact of orthophyre and lamprophyre veins. These supporting measures can well ensure the stability of surrounding rock in weak and broken section, such as sealing the inverted arch by using concrete of C25,reinforcing the inverted arch by steel arch of I10 and anchor construction in the roof. There is great difference between the properties of the weak and broken rocks on both sides, which is the main reason of the large tunnel convergence deformation. The monitoring results can provide reference for similar engineering in the future.