基于SURPAC模型的采空区与露采边坡相互影响的FLAC3D分析

采用SURPAC建立了瓮福磷矿穿岩洞矿段采场的三维地质模型,利用接口程序将模型导入FLAC3D对采空区与露采边坡之间的相互影响进行了计算,并在边坡坡顶、坡脚与采空区四周布置了监测点以监测各点应力与位移的变化。计算结果表明:采空区的存在极大地改变了采空区周边与边坡的应力分布;使得采空区周边水平位移出现明显增加,并且改变了采空区位置周边的竖向位移场,对各个采空区之间的区域的影响最为显著,使得回弹量减小;边坡与采空区监测点的应力与位移随着边坡露采的进行出现规律性的变化;采空区的存在极大地改变了岩体塑性区的分布,对于有采空区边坡,塑性区分布范围随着开挖的进行有减小的趋势,但坡面上出现明显的拉伸破坏区,不利于边坡稳定;采空区使得露采边坡的安全系数降低。

FLAC3D analysis of interaction between goaf and opencut mining slope with 3D geological model using SURPAC

The 3D geological model of Wengfu phosphate mine is built with SURPAC software; and the interaction between the goaf and open cut mining is calculated by the fast Lagrangian analysis of continua in three dimensions (FLAC3D) through the interface program; and the monitoring points of slope and goaf are set in order to monitor the stress and displacement. The calculation results show that the goafs markedly change the stress distribution of slope and around goafs and cause the horizontal displacements of goafs to increase obviously. The goafs also change the vertical displacement and evidently influence the regions between goafs and cause the rebound displacement to decrease. The stresses and displacements appear regularity changes. The goafs evidently change the distribution of plastic zones. To the slope with goafs, the regions of plastic zone decrease with the slope excavation but appear tensile failure zone on the slope surface; and the goafs cause the safety factor of slope to reduce.