首页|Mechanical behaviors and rupture processes of a typical granitic stratum

Mechanical behaviors and rupture processes of a typical granitic stratum

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Granitic veins(GVs)have a significant influence on the mechanical responses of tunnels excavated in granitic strata.Distinguishing the mechanical properties of host granites(HGs),GVs and vein-granite interfaces(VGIs)is critical.For this,this paper analyzed the mechanical behaviors and rupture pro-cesses of typical HG,GV,and VGI samples under uniaxial compression condition.For the rocks studied,although the linear axial stress-strain relation can be identified and the deformation modulus can be determined,the transverse deformation developed nonlinearly with axial stress.As a result,the instantaneous Poisson's ratio increases continuously and may even exceed 0.5,making it extremely difficult to accurately determine the Poisson's ratio.In addition,the studied GV samples were found to be significantly brittle,indicating that large-scale GVs cannot be ignored when assessing rockburst hazards in granitic strata with brittle GVs.In terms of the rupture process,the HG and GV samples were gradually damaged by the formation of small-scale cracks and then ruptured by large cracks formed from small-scale cracks,whereas the VGI samples ruptured along large cracks with significant energy release.By examining the characteristic stress thresholds of these three granites,it is noted that the crack closure stress σcc exceeds both the crack initiation stress σci and the crack damage stress σcd for the HG and VGI samples.The transverse damage to a tested sample appears to be significantly greater than the axial damage,which is essentially related to the rock grain size and grain size distribution.

TunnelGraniteGranitic veinUniaxial compressionAcoustic emission

Xiaofang Nie、Dong Wang、Song Yuan、Liangpu Li、Zhilong Zhang、Zidong Fan、Qin Zhou、Meng Wang、Li Ren

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MOE Key Laboratory of Deep Earth Science and Engineering,College of Architecture and Environment,Sichuan University,Chengdu,610065,China

College of Water Resources and Hydropower,Sichuan University,Chengdu,610065,China

Sichuan Communication Surveying & Design Institute Co.,Ltd.,Chengdu,610065,China

Science and Technology Department of Tibet

XZ202201ZY0021G

2024

岩石力学与岩土工程学报(英文版)
中国科学院武汉岩土力学所中国岩石力学与工程学会武汉大学

岩石力学与岩土工程学报(英文版)

CSTPCD
影响因子:0.404
ISSN:1674-7755
年,卷(期):2024.16(10)