Evaluation of Applicability of Double Shield Tunnel Boring Machines (Ds-Tbm) in Potentially Squeezin Grounds

Abstract

Despite successful use of double shield TBMs in many projects in recent years, presence of shield makes the machine susceptible to entrapment or seizure in weak rocks under high stresses experiencing high convergence. Therefore TBM may get stuck in the complicated geological structures commonly referred to as squeezing ground. This causes slow down or stoppage of machine operation, requiring manual excavation to release the machine, and sometimes even call into question the feasibility of using double shield machines. To realistically evaluate the possibility of machine seizure in such grounds, the interaction between the rock mass and shield, lining and backfilling need to be understood.