文献类型：期刊文献

英文题名：Simplified solution for viscoelastic-plastic interaction between tunnel support and surrounding rock based on MC and GZZ strength criteria

作者：Xu, Chen[1,3];Xia, Caichu[1,2,3];Du, Shigui[1,2]

机构：[1]Ningbo Univ, Inst Rock Mech, Ningbo, Zhejiang, Peoples R China;[2]Shaoxing Univ, Sch Civil Engn, Shaoxing, Zhejiang, Peoples R China;[3]Tongji Univ, Coll Civil Engn, Dept Geotech Engn, Shanghai, Peoples R China

年份：2021

卷号：139

外文期刊名：COMPUTERS AND GEOTECHNICS

收录：SCI-EXPANDED(收录号：WOS:000697027500001)、、EI(收录号：20213310789511)、Scopus(收录号：2-s2.0-85112727506)、WOS

基金：This work was supported by the National Natural Science Foundation of China (Grant No. 51778475) .

语种：英文

外文关键词：Viscoelastic-plastic behavior; Stress path; GZZ strength criterion; Support strategy; Squeezing

外文摘要：The surrounding rock often show obvious rheological characteristics when tunneling in high geostress environment, accompanied by large deformation, slow convergence and increasing support pressure. "Yielding-resistance combination" support inspired by the concept of NATM is widely employed in squeezing tunnels which has been successfully implemented to control the large deformation in many high geostress soft rock tunnels. However, some failure cases indicate that all kinds of "yielding-resistance combination" support strategies are not universally applicable to all squeezing tunnels. To seek an effective support strategy for squeezing tunnels, different kinds of "yielding - resistance combination" supports are summarized into three categories, i. e., "yield before resist" support, "yield - resist" support, and "control - yield - resist" support, which are simplified to different stress paths. A simplified two-stage calculation method, referring the first stage "yielding stage" and the second stage "resist stage", is proposed to derive the time-dependent rock stresses, strains, displacements, displacement rates, and support pressures based on Mohr-Coulomb (MC) criterion and the generalized Zhang-Zhu (GZZ) strength criterion, respectively. Results show that the deformability of plastic rock will be underestimated if the stress path is not considered, the calculated rock displacement will be larger if the actual stress path is considered. The duration of the first stage t(0), the deformation at the first stage Delta u(0) and the primary support pressure p(i0), and the allowable displacement rate u(over dot)(c) are major parameters for the design of tunnel support in squeezing rocks. The allowable displacement rate u. c cannot be very high to ensure the stability of permanent support at the second stage. However, the construction period would be long if the allowable displacement rate u(over dot)(c) is very low which would increase the construction cost. It is suggested that the duration of the first stage t(0) be as short as possible if a relatively low value of u(over dot)(c) is ensured.