Prevention of Large Deformation of Soft Surrounding Rock in Tunnel Construction

Large deformation of surrounding rock makes the internal space a tunnel cannot meet requirements normal use after support, even leads to instability and destruction structure. In order optimize parameters primary support control rock, field tests numerical simulations are carried out. Based on engineering geological conditions monitoring data four important creep improved Burgers model inversed by simulation, considering in construction. The results show that it is feasible crown settlement as indicator determine thickness shotcrete. Short bolts preferentially used arches, combination long short should be sidewall large rock. When excavation method upper-lower bench single-track railway with relatively high-span ratio, horizontal convergence points upper recommended set 0.8-0.9 times height from arch crown, those lower 0.6-0.7 total crown.