Influences of maximum principal stress direction and cross-section shape on tunnel stability  

作　　者：Xuefeng Si Zilong Zhang Xibing Li Guansheng Yi Yong Luo Lihai Tan Kaifeng Han 

机构地区：[1]School of Resources Environment and Safety Engineering,University of South China,Hengyang,421001,China [2]Scientific and Technological Research Platform for Disaster Prevention and Control of Deep Coal Mining,Anhui University of Science and Technology,Huainan,232001,China [3]School of Resources and Safety Engineering,Central South University,Changsha,410083,China [4]College of Meteorology and Oceanology,National University of Defense Technology,Changsha,410073,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2025年第4期2159-2180,共22页岩石力学与岩土工程学报(英文)

基　　金：supported by the National Natural Science Foundation of China (Grant Nos.52304227 and 52104133);Scientific and Technological Research Platform for Disaster Prevention and Control of Deep Coal Mining (Anhui University of Science and Technology) (Grant No.DPDCM2208).

摘　　要：To investigate the effects of the maximum principal stress direction(θ)and cross-section shape on the failure characteristics of sandstone,true-triaxial compression experiments were conducted using cubic samples with rectangular,circular,and D-shaped holes.Asθincreases from 0°to 60°in the rectangular hole,the left failure location shifts from the left corner to the left sidewall,the left corner,and then the floor,while the right failure location shifts from the right corner to the right sidewall,right roof corner,and then the roof.Furthermore,the initial failure vertical stress first decreases and then increases.In comparison,the failure severity in the rectangular hole decreases for variousθvalues as 30°>45°>60°>0°.With increasingθ,the fractal dimension(D)of rock slices first increases and then decreases.For the rectangular and D-shaped holes,whenθ=0°,30°,and 90°,D for the rectangular hole is less than that of the D-shaped hole.Whenθ=45°and 60°,D for the rectangular hole is greater than that of the D-shaped hole.Theoretical analysis indicates that the stress concentration at the rectangular and D-shaped corners is greater than the other areas.The failure location rotates with the rotation ofθ,and the failure occurs on the side with a high concentration of compressive stress,while the side with the tensile and compressive stresses remains relatively stable.Therefore,the fundamental reason for the rotation of failure location is the rotation of stress concentration,and the external influencing factor is the rotation ofθ.

关 键 词：Maximum principal stress direction Cross-section shape True-triaxial experiment Failure characteristics Fractal dimension Theoretical analysis 

分 类 号：TU45[建筑科学—岩土工程]