Abstract
This study is to quantitatively clarify the mutual influence due to the adjacent excavation near to the existed tunnel by using the base friction model test and the finite deformation difference method. The varied factors included the mechanical character of the ground, the nearness and depth of tunnels. In order to reduce the influence to the existed tunnel, the reinforcement method of pillar between double tunnels is suggested through systematic bolting, and the supporting and stabilizing effect on the extent of failure zone and deformational behavior of surrounding rock mass and pillar is investigated in detail, by changing the pattern and length of grouted rockbolts, according to the distance of adjacent tunnel centers and the competency factor of ground.
