Modified ground response curve(GRC)in strain-softening rock mass based on the generalized Zhang-Zhu strength criterion considering over-excavation

作     者：Chen Xu Caichu Xia Changling Han 

作者机构：Institute of Rock MechanicsNingbo UniversityNingboZhejiangChina Department of Geotechnical EngineeringCollege of Civil EngineeringTongji UniversityShanghaiChina CCCC First Highway Consultants Co.LtdXi’anShaanxiChina 

出 版 物：《Underground Space》 (地下空间（英文）)

年 卷 期：2021年第6卷第5期

页      面：585-602页

核心收录：

学科分类：081406[工学-桥梁与隧道工程] 08[工学] 0818[工学-地质资源与地质工程] 0903[农学-农业资源与环境] 0714[理学-统计学（可授理学、经济学学位）] 0814[工学-土木工程] 0701[理学-数学] 082301[工学-道路与铁道工程] 0823[工学-交通运输工程] 

基　　金：supported by the National Natural Science Foundation of China(Grant No.51778475) 

主　　题：Ground response curve Large strain Over-excavation Strain-softening Soft rock tunnel 

摘      要：The ground response curve(GRC)depicts the relationship between support reaction force and ground displacement,which improves the understanding of ground-support interaction and provides important references to the tunnel ***,it is difficult to anticipate the tunneling-induced large deformation with sufficient reliability in soft rock with high geostress since the small strain theory is not *** large deformation occurs,the tunnel needs to be ***,the GRC should be modified considering the enlarged excavation radius since the actual excavation radius is usually greater than the designed *** overcome the shortcomings of small strain theory in recognizing ground-support interaction under large deformation circumstances,a new large strain numerical approach for modifying the GRC was proposed considering over-excavation in strain-softening rock masses based on the generalized Zhang-Zhu strength criterion.A case study was conducted based on the Lianchengshan tunnel in *** modified GRC was employed to investigate the ground-support behavior for different support schemes and to explore the applicability of the stress release *** with field tests,the proposed approach was *** comparing with GRCs proposed by previous work,the present modified GRC was proved to be superior to *** studies were conducted and it is found that over-excavation,for example,reserving a very large clearance between the surrounding rock and the support,is necessary to reduce ground pressure to a large *** yielding supports which can provide high support pressure during the process of deformation are highly recommended when tunneling in high geostress ***,if the initial geostress is not very high,it is not necessary to pursue unwarranted overexcavation since the ground pressure applied on the support is mainly the loosening stress when the deformation is *** support stiffness should be provi