Deformation Potential of the Guanjiao Tunnel Based on Original Geo-stress
(1 Key Laboratory of Road & Bridge and Underground Engineering of Gansu Province, Lanzhou Jiaotong University, Lanzhou 730070; 2 National and Provincial Joint Engineering Laboratory of Road & Bridge Disaster Prevention and Control, Lanzhou Jiaotong University, Lanzhou 730070; 3 China Railway First Survey and Design Institute Group Ltd., Xi′an 710043; 4 School of Civil Engineering, Northwest University for Nationalities, Lanzhou, Gansu 730030)
Abstract：
Aiming at the surrounding rock deformation of the Erlangdong fault bundle at the location of the new Guanjiao tunnel under high geo-stress, a concept of surrounding rock deformation potential and its classification criterion are put forward based on the geo-stress field extension results from the original geo-stress test and the main influencing factors. The distribution of the deformation potential in the Guanjiao tunnel is obtained by sample statistics and the neural network algorithm. The results show that the ridge section, sections with high and extremely high geo-stress, large fault section and fault bundle section of the Guanjiao tunnel have a deformation potential of gradesⅠ, Ⅱ and Ⅲ, and only partial sections have common deformation potential, which indicates the Guanjiao tunnel has large deformation potential under the complex conditions of soft rock and extremely high geo-stress. By determining the deformation potentials of each section in the Guanjiao tunnel, most of the monitoring results are controlled within the scope of common deformation after the means of correction, optimization design and construction, and the rest of the deformations are controlled within the scope of grade I. This achievement provides an accurate and practical forecasting and controlling method to solve the problem of large deformation in similar conditions.
2018, Vol. 55 