摘要
锚固软岩力学特性是深部软岩巷道围岩稳定性控制的重要依据。基于离散元软件PFC,构建能够模拟深部软岩力学行为的Burgers黏结模型,并建立拉-压复合应力下的预制裂隙锚固软岩数值模型,以探究不同裂隙倾角下锚固软岩中锚杆力学特性、锚岩力学特性及新增裂隙倾角分布规律,最终建立含拉拔荷载、裂隙倾角参数的轴向应变线性回归模型,从而对锚固软岩轴向应变发展规律进行一定预测。结果表明:不同倾角裂隙会使裂隙处的锚杆轴力值、表面剪应力值产生不同程度减小,当裂隙倾角为45°时,二者减小程度最大,此时拉-压复合应力使锚固体在锚杆-岩体接触界面处的破坏倾向性达到最大;随着预制裂隙与锚杆夹角的减小,锚固体轴向应变量逐渐增大,且拉-压复合应力作用过程中其轴向应变量与裂隙倾角值、拉拔荷载值呈明显线性关系;随着预制裂隙与锚杆夹角的减小,新增裂隙数量逐渐增加,其中裂隙倾角大多呈45°与135°左右,少有垂直或平行于锚杆的裂隙产生。
The mechanical properties of anchored soft rock are considered as an important basis for controlling the stability of surrounding rock in deep soft-rock roadways.Based on the discrete element software PFC,a Burgers bonded model was constructed to simulate the mechanical behavior of deep soft rock,and a numerical model of pre-cracked anchored soft rock under tensile-compressive composite stress was established to investigate the mechanical properties of anchor bolts and anchored rock and the distribution pattern of inclination angle of new cracks in anchored soft rock with different initial crack inclination angles.Ultimately,a linear regression model of axial strain with the inclusion of pull-out loads and crack angle parameters was established for the purpose of predicting the development of axial strain in anchored soft rock.According to the research findings,the axial force and the surface shear stress of anchor bolts at cracks will be reduced to varying degrees under different crack angles,and their reductions both reach the peak under the crack angle of 45°.In this case,the tensile-compressive composite stress induces the highest failure propensity of anchored rock at the anchor-rock contact interface.As the angle between the pre-fabricated crack and the anchor bolt decreases,the axial strain of the anchored rock gradually rises,and it varies linearly with the crack angle and the pull-out load under the action of the tension-compressive composite stress.As the angle between the pre-fabricated crack and the anchor bolt decreases,the number of new cracks gradually grows.Their angles are mostly about 45°and 135°,and only few of them are perpendicular or parallel to the anchor bolt.
作者
许永震
栾兆群
徐兴奎
王磊
崔力
缪澄宇
孙晓明
XU Yongzhen;LUAN Zhaoqun;XU Xingkui;WANG Lei;CUI Li;MIAO Chengyu;SUN Xiaoming(Gansu Provincial Road Traffic Construction Group Corporation Limited,Lanzhou,Gansu 730030,China;Load Cell Sensor Technique Co Ltd,Shandong University of Science and Technology,Tai'an,Shandong 271019,China;Weishan Jinyuan Coal Mine,Jining,Shandong 272000,China;State Key Laboratory for Tunnel Engineering,China University of Mining and Technology-Beijing,Beijing100083,China;School of Mechanics and Civil Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China)
出处
《采矿与安全工程学报》
EI
CSCD
北大核心
2024年第6期1134-1147,共14页
Journal of Mining & Safety Engineering
基金
国家自然科学基金项目(52174096,52304110)。
关键词
深部软岩
锚固岩体
预制裂隙
拉-压复合应力
力学特性
离散元模拟
deep soft rock
anchored rock
pre-fabricated crack
tensile-compressive composite stress
mechanical properties
discrete element simulation
作者简介
许永震(1971-),男,甘肃省兰州市人,高级工程师,主要从事公路项目管理及隧道工程岩石力学方面的研究;通信作者:孙晓明,E-mail:CUMTB_sunxiaoming@163.com,Tel:13801166205。
