文献类型：期刊文献

英文题名：Large Deformation Mechanism of Foliated Rock and NPR Anchor Cable Support Technology in the Changning Tunnel: A Case Study

作者：Sun, Xiaoming[1,2];Zhang, Bo[1,2];Yang, Kang[4];Guo, Pengfei[3];Tao, Zhigang[1,2]

机构：[1]State Key Lab Geomech & Deep Underground Engn, Beijing 100083, Peoples R China;[2]China Univ Min & Technol, Sch Mech & Civil Engn, Beijing 100083, Peoples R China;[3]Shaoxing Univ, Sch Civil Engn, Shaoxing 312000, Peoples R China;[4]Guangxi Rd & Bridge Engn Grp Co Ltd, Nanning 530200, Peoples R China

年份：2022

卷号：55

期号：11

起止页码：7243

外文期刊名：ROCK MECHANICS AND ROCK ENGINEERING

收录：SCI-EXPANDED(收录号：WOS:000842210300001)、、EI(收录号：20223612678480)、Scopus(收录号：2-s2.0-85136994359)、WOS

基金：This work was supported by the National Natural Science Foundation of China (Grant No. 41941018).

语种：英文

外文关键词：Foliated rock mass; Large deformation mechanism; NPR anchor cable; Field test; Field monitoring

外文摘要：To solve the large deformation problem of foliated rock masses in the Changning Tunnel, rock mechanics experiments and discrete fracture numerical simulation calculations were carried out. The mechanical properties and large deformation mechanism of the foliated rock mass are analyzed. The results show a large strength dispersion in jointed rocks with different dip angles. Rock strata compression bending and shear slip caused by the rock strata structure and tectonic stress are found to be the main causes of large deformation in the Changning Tunnel. Five negative Poisson's ratio (NPR) anchor-cable support schemes were designed, and field experiments were carried out. The NPR anchor cable can maintain a constant support force to strengthen the surrounding rock and release the deformation energy by allowing the deformation of the surrounding rock through a sliding device. In the field test, the number of anchor cables in the five support schemes was gradually reduced. The reliability of these support schemes was evaluated by various monitoring methods, including surrounding rock displacement, pressure between the primary support and surrounding rock, pressure between the primary support and secondary lining, internal stress of the steel arch, and deep displacement and axial force of the NPR anchor cable. The monitoring results show that the five schemes can control the large deformation of the surrounding rock to varying degrees. The maximum deformation of the surrounding rock under the original support scheme was greater than 1 m, but the maximum deformation under the NPR anchor cable support was less than 150 mm, and the support structures were also within the safe range. Therefore, NPR anchor cable support can effectively control the large deformation of the surrounding rock in the Changning Tunnel. The research results can provide a reference for the prevention and control of large deformation in similar projects.