Abstract：Based on the construction of the Yangjiaping tunnel in Chengdu—Lanzhou railway, 30 meters long tunnel with typical surrounding rock was chosen as the experimental section. The follow items were compared when there exists ordinary bolt or early strength bolt, including displacement of tunnel inner perimeter, pressure between surrounding rock and primary lining, internal force of the steel arch truss and axial force of the bolts. The mechanism of the early strength bolt in the high geo-stress layered soft rock tunnel is discussed. The results show that the axial force of the anchor bolt which in high stress soft rock tunnel is the pulling force, and the axial force of early-strength bolt is larger than that of the ordinary bolt, which can reduce the displacement of tunnel by 40%. The early-strength bolt makes the pressure of the surrounding rock of the tunnel side wall and the strain of the steel arch truss in the vault area reduced, so that the distribution of surrounding rock pressure and the strain distribution of steel arch truss tend to be uniform. The early-strength bolts improve the strength of the surrounding rock layer by grouting material deep into the rock, and inhibit the gradual failure process of surrounding rock by playing anchoring effect in time, thus the plastic zone of the surrounding rock is reduced. The pressure between surrounding rock and primary lining is reduced by lengthening the pick-up length of the bolt, then the stress condition of the tunnel support is improved, the tunnel deformation is effectively controlled.
郭小龙 谭忠盛 李磊 罗宁宁 夏平. 早强锚杆在高地应力层状软岩隧道中的应用研究[J]. 土木工程学报, 2017, 50(S1): 59-64.
Guo Xiaolong Tan Zhongsheng Li Lei Luo Ningning Xiaping. Application of early strength bolt in high geostress layered soft rock tunnel. 土木工程学报, 2017, 50(S1): 59-64.
