Based on the characteristics of the deep circular tunnel, the surrounding rock was divided into three regions： the cracked region, the plastic region and the viscoelastic region. The process of rock stress deformatio...Based on the characteristics of the deep circular tunnel, the surrounding rock was divided into three regions： the cracked region, the plastic region and the viscoelastic region. The process of rock stress deformation and change was divided into three stages after the roadway excavation. By using the elastic-plastic mechanics theory, the analytical solutions of the surrounding stress and displacement at different stages and the radii of cracked and plastic regions were formulated. We additionally explained the surrounding rock stress and displacement which appeared in practical project. Simultaneously, based on the problem which emerged from a mine in Xuzhou during the excavating process of rock roadway＇s transport, we got the theoretical solutions for the stress and displacement in the process of rock roadway＇s excavation and considered that the broken area of rock roadway was largely loosing circle. The results indicate that according to the rheological characteristics of surrounding rock, in the primeval excavation of rock roadway, we should increase the length of anchor bolt and cooperate it with anchor nets cable-U steel supporting frame. In addition, when the deformation rate of the surrounding rock is descending after the 15 days＇ excavation, we should use the ＂three anchor＂ supporting method （anchor bolt spray, anchor note and anchor rove） and set aside about 20 cm as the reserved deformation laver.展开更多
基金provided by the National Basic Research Program of China (No. 2007CB209408)the National Natural Science Foundation of China (No. 51074166)the Research Innovation Program for College Graduates of Jiangsu (No.CX098B_108Z)
文摘Based on the characteristics of the deep circular tunnel, the surrounding rock was divided into three regions： the cracked region, the plastic region and the viscoelastic region. The process of rock stress deformation and change was divided into three stages after the roadway excavation. By using the elastic-plastic mechanics theory, the analytical solutions of the surrounding stress and displacement at different stages and the radii of cracked and plastic regions were formulated. We additionally explained the surrounding rock stress and displacement which appeared in practical project. Simultaneously, based on the problem which emerged from a mine in Xuzhou during the excavating process of rock roadway＇s transport, we got the theoretical solutions for the stress and displacement in the process of rock roadway＇s excavation and considered that the broken area of rock roadway was largely loosing circle. The results indicate that according to the rheological characteristics of surrounding rock, in the primeval excavation of rock roadway, we should increase the length of anchor bolt and cooperate it with anchor nets cable-U steel supporting frame. In addition, when the deformation rate of the surrounding rock is descending after the 15 days＇ excavation, we should use the ＂three anchor＂ supporting method （anchor bolt spray, anchor note and anchor rove） and set aside about 20 cm as the reserved deformation laver.
