School of Safety and Emergency Management Engineering,Taiyuan University of Technology
Research Center of Green MiningEngineering Technology in Shanxi Province,Taiyuan University of Technology
College of Mining Technology,Taiyuan University ofTechnology
Department of Earth and Space Science,Southern University of Science and Technology
State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology
Schoolof Mechanics and Civil Engineering,China University of Mining and Technology

在实际地下工程开挖中,岩石处于采动应力状态,其采动应力路径用应力Lode角表示。基于多功能真三轴流固耦合试验系统,开展相同静水压力、不同应力Lode角的真三轴力学试验,研究不同应力Lode角对砂岩的扩容特性和非共轴性的影响。试验结果表明:应力Lode角的增加在一定程度上反映出卸荷作用对砂岩真三轴试验变形的影响。对比应力Lode角在-30°~0°和0~30°的主应力变化量可以发现:最大主应力变化量比较均匀,中间主应力变化量下降,最小主应力变化量上升。随着应力Lode角的增加,最大主应变压缩程度下降,中间主应变由膨胀转变为压缩,最小主应变膨胀程度增加,且最小主应力方向的膨胀量相对于最大主应力方向的压缩量增加。应力Lode角从-30°变化到30°,随着最大主应变的增加,体积应变呈现先减小后增加的趋势。引入应变偏应力柔量,随着应力Lode角的增加,广义剪切应力对最大主应力方向的压缩变形作用减弱,对最小主应力方向的膨胀变形作用先增强后趋于平稳;体积应变偏应力柔量整体呈现下降趋势。非共轴性表现为应力路径和应变路径不重合,不同应力Lode角下的应变路径均向低Lode角方向演化。引入偏转量,应力Lode角从-30°变化到30°,偏转量呈现先上升后下降的趋势。

In actual underground engineering excavation,the rock is in a mining stress state,and its mining stress pathis represented by the stress Lode angle. Based on the multifunctional true triaxial fluid⁃solid coupling test system,vari⁃ous true triaxial mechanical tests with same hydrostatic pressure and different stress Lode angles were carried out tostudy the effects of different stress Lode angles on the dilation characteristics and non⁃coaxiality of sandstone. The testresults show that the increase of stress Lode angle reflects to some extent the effect of unloading action on the deforma⁃tion of sandstone true triaxial test. Comparing the amount of principal stress variation for stress Lode angle from -30 to0° and 0 to 30°,it can be found that the maximum principal stress variation is more uniform,the middle principalstress variation decreases and the minimum principal stress variation increases. As the stress Lode angleincreases,the degree of compression of the maximum principal strain decreases,the intermediate principal strain chan⁃ges from expansion to compression,and the degree of expansion of the minimum principal strain increases,and thestress Lode angle changes from -30° to 30°,and the volume strain shows a tendency to decrease and then increaseas the maximum principal strain increases. Introducing the strain⁃partial stress flexibility,with the increase of thestress Lode angle,the effect of generalized shear stress on the compressive deformation in the direction of the maximumprincipal stress is weakened,and the effect on the expansion deformation in the direction of the minimum principalstress is first enhanced and then tends to be smooth. The volume strain partial stress flexibility shows an overall de⁃creasing trend. The non⁃coaxiality is manifested by the non⁃coincidence of stress and strain paths,and the strain pathsunder different stress Lode angles all evolve toward the low Lode angle. With the introduction of deflection, thestress Lode angle changes from -30° to 30°,and the deflection shows a rising and then decreasing trend.

国家杰出青年科学基金资助项目(51925402);国家自然科学基金资助项目(51804211);山西省应用基础研究计划资助项目(201901D211037)

李文璞,王泽,冯国瑞,等. 真三轴采动卸荷条件下砂岩扩容行为和非共轴性研究[J].煤炭学报,2023,48(S1):71-81.

LI Wenpu,WANG Ze,FENG Guorui,et al. Research on sandstone dilation behavior and non⁃coaxiality under dif⁃ferent stress Lode angle conditions[J]. Journal of China Coal Society,2023,48(S1):71-81