Study on influence partition of tunneling adjacent to multi-storey building in upper-soft and lower-hard stratum

Based on several examples relating to tunneling near the multi-storey building in Qingdao Jiaozhou bay tunnel connecting engineering, the study on influence partition of tunneling adjacent to multi-storey building has been conducted by the finite element strength reduction method. The safety factor of 2.0 was defined as the boundary of the strong to weak influence zone, and the peak safety factor was considered as the boundary of weak to none influence zone. Based on the distribution of safety factors in three cases with relative scale of 2, 1, 1/2, and considering the convenience use on site, a influence partition map of tunneling to the existing multi-storey building in upper-soft and lower-hard stratum has been proposed.