Abstract：
Using the construction of the Yangjiawan tunnel on the Lanzhou-Chongqing railway as an example, this paper analyzes the degree and cause of deformation of surrounding rock and support during and after breaking through. By installing a primary support at both sides of the break-through section and using pre-support at the non-break through section, support deformation induced by breaking through was controlled and excavation stability and construction safety were guaranteed.
2012, Vol. 49 