THE PREDICTION AND CONTROL OF REBOUND DEFORMATION OF THE EXISTED TUNNELS RIGHT UNDER EXCAVATION
基坑工程下已运行地铁区间隧道上抬变形的控制研究与实践

The protection of the two existed tunnels is presented, which ase right under Shanghai square excavation and are protected through two methods: ground improvement and considering time-space construction procedure. Due to the combining use of the two methods, the normal operation of the two tunnels have been successfully guaranteed. It is analysed in great details how the time and space affect on the rebound deformation of the existed tunnels and how the tunnel deformation is predictde with the thory of residual stress. At theend, the recorded deformations of the two tunnels are given out and the tunnel deformation is divided into three stage. In a word, this excavation made a good example for the future similar engineering.