ABSTRACT
We always encounter the situation of building new overlapped tunnels over or under the built tunnels with the improvement of urban traffic demand and resources exhaustion of urban underground space, and the distance between building and built tunnels is becoming smaller and smaller. So, we must face the problem how to ensure the stability of the built tunnels during construction of the building tunnels. The studying method for this question main is numerical simulation at present (CHEN 2003, FANG&HE 2007). However, these papers mainly studied surface settlement, and did not consider support stability of the built tunnel affected by the buildingoverlapped tunnels (LIN 2006, FANG&ZHANG 2007). In this paper, taking Da Ping tunnel as an example, the support stability affected by the building tunnels is analyzed.
