of backfill grout injection from the end of skin plate

ABSTRACT: Recently, tunnelling with TBM is getting popular for the construction of cable tunnel in urban area. Mechanized tunnelling method using shield TBM has various advantages such as minimization of ground settlement and prevention of vibration induced by blasting that should be accompanied by conventional tunnelling. In Korea, earth pressure balance (EPB) type shield TBM has been mainly used. Despite the popularity of EPB shield TBM for cable tunnel construction, study on the mechanical behavior of cable tunnel driven by shield TBM is insufficient. Especially, the effect of backfill grout injection on the behavior of cable tunnel driven by shield TBM is investigated in this study. Tunnelling with shield TBM is simulated using 3D FEM. The distance of backfill grout injection from the end of shield skin varies. Sectional forces such as axial force, shear force and bending moment are monitored. Vertical displacement at the ground surface is measured. Futhermore, the relation between volume loss and the distance of backfill grout injection from the end of skin plate is derived. Based on the stability analysis with the results obtained from the numerical analysis, the mos