Abstract The deformation mechanism and stability control of surrounding rock are one of the key technologies in tunnel construction. According to the spatial effects of construction behavior on pilot tunnel excavation,the deformation law of surrounding rock in tunnel construction was simulated and comparatively analyzed with full face method and bench tunnel construction method by using the finite difference software FLAC3D. Results show that the displacement rate and the displacement after excavation caused by pilot tunnel construction are smaller than the other two methods,which are beneficial to the stability of surrounding rock. With the increase of buried depth,the displacement increases linearly,whereas the horizontal convergence increases linearly and the crown settlement increases non-linearly with the increase of lateral pressure coefficient. The proportion of the displacement before excavation increases with the increase of the depth,whereas the proportion of the horizontal convergence before excavation increases and the proportion of the crown settlement before excavation decreases with the increase of the lateral pressure coefficient. Combined with the field monitoring data,the reliability of conclusions was verified. The obtained conclusions have certain reference to similar projects,important significance and engineering value.
|
Received: 30 May 2013
|
|
|
|