Surrounding Rock Consolidation numerical Analysis of Unsymmetrical Loading Tunnel

Jet grouting piles were used to reinforce overlying soil of shallow buried tunnel under unsymmetrical pressure. Displacement and strain was simulated during tunnelling with three steps excavation method under condition of reinforcement and unreinforcement. The results show that larger vertical displacement and shear strain occur during excavation of upper bench, and it changes very little when center and subjacent bench was excavated. This is because upper bench is located in soil, part of center bench in rock, and the whole subjacent bench in rock. Largest shear strain occurs at the arch foot of upper bench. It is concluded that jet grouting piles can control surrounding rock deformation effectively.