Numerical investigation of geostress influence on the grouting reinforcement effectiveness of tunnel surrounding rock mass in fault fracture zones  

作　　者：Xiangyu Xu Zhijun Wu Lei Weng Zhaofei Chu Quansheng Liu Yuan Zhou 

机构地区：[1]The Key Laboratory of Safety for Geotechnical and Structural Engineering of Hubei Province,School of Civil Engineering,Wuhan University,Wuhan,430072,China [2]Wuhan University Shenzhen Research Institute,Shenzhen,518057,China [3]State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University,Wuhan,430072,China [4]Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,430071,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2024年第1期81-101,共21页岩石力学与岩土工程学报（英文版）

基　　金：This work was supported by the Guangdong Basic and Applied Basic Research Foundation(Grant No.2021A1515110304);the Na-tional Natural Science Foundation of China(Grant Nos.42077246 and 52278412).

摘　　要：Grouting is a widely used approach to reinforce broken surrounding rock mass during the construction of underground tunnels in fault fracture zones,and its reinforcement effectiveness is highly affected by geostress.In this study,a numerical manifold method(NMM)based simulator has been developed to examine the impact of geostress conditions on grouting reinforcement during tunnel excavation.To develop this simulator,a detection technique for identifying slurry migration channels and an improved fluid-solid coupling(FeS)framework,which considers the influence of fracture properties and geostress states,is developed and incorporated into a zero-thickness cohesive element(ZE)based NMM(Co-NMM)for simulating tunnel excavation.Additionally,to simulate coagulation of injected slurry,a bonding repair algorithm is further proposed based on the ZE model.To verify the accuracy of the proposed simulator,a series of simulations about slurry migration in single fractures and fracture networks are numerically reproduced,and the results align well with analytical and laboratory test results.Furthermore,these numerical results show that neglecting the influence of geostress condition can lead to a serious over-estimation of slurry migration range and reinforcement effectiveness.After validations,a series of simulations about tunnel grouting reinforcement and tunnel excavation in fault fracture zones with varying fracture densities under different geostress conditions are conducted.Based on these simula-tions,the influence of geostress conditions and the optimization of grouting schemes are discussed.

关 键 词：Numerical manifold method(NMM) Grouting reinforcement Geostress condition Fault fracture zone Tunnel excavation 

分 类 号：U451.2[建筑科学—桥梁与隧道工程]