诱导巷道的围岩松动破坏区数值研究

Numerical Study on Damage Zones of the Induced Roadway Surrounding Rock

当前多数矿山已进入深部开采,而深部硬岩具有高储能、受扰动易破坏的特征,根据这些特点,在矿体中布置巷道诱导岩体破裂,为后续机械开采提供可能。以贵州开阳磷矿为工程背景,利用FLAC3D软件模拟深部巷道开挖,研究断面形状、地应力水平和侧压系数对巷道开挖的影响,从而得出岩体的破裂规律。数值模拟结果表明:巷道断面形状对围岩变形影响较大,而矩形巷道周围岩体产生的位移和塑性破坏区均最大;巷道位移和塑性破坏区随应力水平的增加而增大;围岩破坏和位移随侧压系数的增大表现出先减小后增大的趋势。在高应力水平和高侧压系数下,采用矩形断面方式开挖巷道,围岩产生的位移和塑性破坏区最大,致裂效果最好,有利于机械切割回采。

With more mines into deep mining,hard rock in high geo-stress shows high energy storage and generates fractures easily by disturbances,and also roadway excavation accelerate surrounding rock cracking or even broken,so the fracturing rock can be cutting by mechanical tools. Those characters make it possible to operate continuous mechanized mining in the hard-rock ore-body. In this paper,Guizhou Kaiyang phosphate mine is chosen as an engineering background,the simulations of the roadway excavation damaging process were conducted by FLAC3D,and the displacement and plastic damage zone of surrounding rock of three shape roadway section were studied.The results show that the damage scale of the rectangular section is maximum,as well as the displacement,and that the displacement damage zone scale of surrounding rock increase apparently with the geo-stress levels increasing.The failure and displacement of surrounding rock decrease first and then increase with the increasing of lateral pressure coefficient. In the high stress level and high lateral pressure coefficient conditions,the surrounding rock of rectangular section tunnel excavation has a greater displacement and larger plastic failure zone,and the fracturing effect are optimum.These results present a theoretical basis for the layout and the design of induced roadway and illustrate subsequent fracturing rock can be cut by mechanical tools.