高应力-渗流耦合作用下不同节理产状对岩体渗流及其塑性区的影响

Influence of Various Joint Occurrences on Seepage and Plastic Zone of Rock Mass under High Stress-Seepage Coupling

为探讨高应力-渗流耦合作用下不同节理产状对隧洞岩体损伤破坏的影响,基于隧洞高应力、渗流现场监测成果,采用三维离散元软件建立应力-渗流耦合下的节理岩体数值模型,分析节理岩体开挖后渗流场的分布特征,以及不同节理产状对围岩渗流模式、塑性区破坏的影响。结果表明:1)节理倾角对渗流场的分布形态起主导作用,开挖后隧洞渗流场呈“漏斗状”,随倾角方向发生偏转,形成与之平行的“斜漏斗”,且当倾角越陡,围岩破坏面积越大。2)节理间距对渗流场的变化幅度起主导作用,整体呈现先增大后减小、最后趋于稳定的趋势,且节理间距每减小1/2,塑性区面积增大10.29%。3)节理初始隙宽的不同会改变节理面的渗透性,且沿径向14 m内的隙宽发育主要受高应力-渗流耦合作用影响。

To explore the influence of different joint occurrences on the damage and failure of tunnel rock mass under the coupling action of high stress-seepage,based on the on-site monitoring results of high stress and seepage flow in tunnels,a numerical model of joint rock mass under stress-seepage coupling is established using three-dimensional discrete element software,and the distribution characteristics of seepage fields after excavation of joint rock masses and the influence of different joint production conditions on the seepage pattern and plastic zone failure of surrounding rocks are analyzed.The results show the following:(1)The joint inclination angle plays a leading role in the distribution pattern of the seepage field,the tunnel seepage field shows a funnel shape after excavation,and the deflection occurs with the direction of inclination to form a parallel"oblique funnel".(2)The larger the inclination angle,the larger the area of surrounding rock destruction;the joint spacing plays a leading role in the change amplitude of the seepage field,and the overall trend is to increase first,then decrease,and finally stabilize.(3)The area of the plastic zone increases by 10.29%for each doubling of the joint spacing;the difference in the initial gap width of the joint changes the permeability of the joint surface,and the gap width development along the radial direction of 14 m is mainly affected by the coupling of high stress-seepage.