层理铁矿石剪切力学性能试验研究  

Experiment of shear mechanical properties of layered iron ore

作　　者：汪昕 幸安康 曾子强 姜祎 徐建宇 王晓南 刘造保 WANG Xin;XING An-kang;ZENG Zi-qiang;JIANG Yi;XU Jian-yu;WANG Xiao-nan;LIU Zao-bao(Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines,Northeastern University,Shenyang,Liaoning 110819,China;Institute of Deep Engineering and Intelligent Technology,Northeastern University,Shenyang,Liaoning 110819,China;Benxi Longxin Mining Co.,Ltd.,Benxi,Liaoning 117013,China)

机构地区：[1]东北大学深部金属矿山安全开采教育部重点实验室,辽宁沈阳110819 [2]东北大学深部工程与智能技术研究院,辽宁沈阳110819 [3]本溪龙新矿业有限公司,辽宁本溪117013

出　　处：《岩土力学》2025年第4期1039-1048,共10页Rock and Soil Mechanics

基　　金：国家重点研发计划(No.2023YFC2907201);辽宁省科学技术计划(No.2023JH1/10400004);国家自然科学基金(No.52374083)。

摘　　要：陡倾薄层状矿体在开挖扰动下,易呈现高切向应力导致边墙弯折破断或弯曲内鼓破坏,破坏模式与层理岩体的力学性质紧密相关。为研究思山岭铁矿层状矿体在剪切破坏过程中的变形和强度性质及破坏特征,开展不同层理倾角和围压下层状岩石三轴剪切试验。试验结果表明:思山岭层理铁矿石试样的峰值强度、轴向和环向变形、破坏模式受围压和层状节理角度影响显著。层理角度的增加使得试样抗剪强度呈现先增加后减小的趋势,轴向变形和环向变形呈现波浪形变化;围压的增加使得试样峰值剪切强度有显著的提高,轴向剪切位移也有增加的趋势,环向变形呈减小的趋势。层理铁矿石试样的破坏模式受层理倾角和围压控制,在层理倾角为0°和30°时,试样发生以应力控制型为主的破坏;层理倾角为45°时,试样发生应力-结构控制型的破坏;层理倾角为60°和90°时,试样发生以结构控制型为主的破坏。最后基于试验结果,给出了同时考虑中主应力和矿石层理倾角的破坏判据,研究结果可为思山岭铁矿的采场和支护设计提供重要支撑。Steeply dipping thin-layered ore bodies are prone to exhibit failure modes such as bending and breaking of the sidewall or bending and internal bulging caused by high tangential stress,which are closely related to the mechanical properties of the bedded rock mass.In order to investigate the deformation,strength properties,and failure characteristics of Sishanling layered iron ore during the shear failure process,conventional triaxial shear tests were conducted on layered rocks under various bedding dip angles and confining pressures.The test results show that the peak strength,axial displacement,circumferential deformation and failure mode of stratified iron ore samples are affected by confining pressure and layered joint angle.With an increase in the bedding angle,the shear strength of the specimen initially increases and then decreases,while the axial and circumferential deformations exhibit a‘wave-like’trend.Moreover,as the confining pressure increases,the peak shear strength of the specimen significantly improves,the axial shear displacement increases,and the circumferential deformation decreases.In addition,failure mode of bedding iron ore specimen is controlled by both the bedding dip angle and confining pressure.The study reveals that the failure mode is stress-controlled when the bedding dip angles are 0°and 30°.At a bedding dip angle of 45°,the specimens exhibit a stress-structure controlled failure mode,while for angles at 60°and 90°,the failure mode is predominantly controlled by the structure.Based on the test results,a failure criterion is proposed considering both the intermedium principle stress and the ore bedding angle.The test results could offer important technique support for the stope and blasting and also the ground support design.

关 键 词：层理倾角 围压 强度 变形 破坏模式 

分 类 号：TU452[建筑科学—岩土工程]