Abstract: The control of the deformation induced by tunneling in soft ground with high geostress is studied, with Muzhailing tunnel on LanzhouChongqing railway as an example. Trails are made on pilot tunneling method and bench excavation method and the deformation controlling effects of these two methods are analyzed. The rules of the deformation occurring at different steps of bench excavation method are summarized. The conclusions drawn are as follows: 1) Regarding the pilot tunneling method and bench excavation method, the first bench is of great importance for the control of the tunnel deformation; 2) The overall deformation control effects of these two methods are similar for tunnels in soft ground with high geostress, therefore proper excavation method should be selected from these two methods, on basis of the construction efficiency; 3) The invert should be installed as soon as possible after the tunnel excavation, which is favorable to the deformation control. 

Key words: high geostress, soft ground tunnel, deformation occurring during construction, control method