瓦房子锰矿巷道破坏机理及支护参数确定

Failure mechanism and support parameters determined of roadway in Wafangzi manganese ore mine

瓦房子锰矿雹神庙采区运输巷道,地压显现严重,底膨、两帮内挤、顶板下沉,严重制约矿山生产。在分析巷道破坏机理的基础上,考虑巷道断面的承压能力及允许变形量,由原断面改为2.6m×2.7m的顶底板双拱形断面,通过土力学极限平衡力学模型的巷道底板塑性区范围和最大破坏深度以及锚杆悬吊理论计算公式,综合确定锚杆长度为1.7m,配以100mm×100mm的金属网,厚度80~100mm喷射混凝土的全断面喷锚网支护形式。在不同侧压力系数条件下,利用FLAC软件模拟了九盘的巷道变形,当侧压力系数约为2.5时,其巷道变形程度与瓦房子锰矿九盘运输巷道的实际破坏过程和破坏程度相符。在此应力环境下,数值模拟表明,优化后巷道顶板和两帮位移都明显减小,无明显的应力集中现象,并利用收敛监测十盘施工段巷道,随着时间推移,各监测点顶板和两帮位移趋于收敛,顶板位移收敛于10~20mm,两帮位移收敛于11~20mm,越靠近掌子面的巷道位移量越小,优化后的巷道断面和支护方式可有效控制瓦房子锰矿运输巷道的变形破坏。

The ground pressure appeared seriously in roadway of Wafangzi manganese ore mine,such as floor heave,two sides of roadway to squeeze,roof subsidence,which seriously restricting the mine production.According to the roadway failure mechanism and bearing pressure ability of different shape of road section and allowable deformation,the section size was determined 2.6m×2.7m,the section shape was determined double arch in roof and floor.The plastic zone and the maximum damage depth in roadway floor were determined based on the soil mechanics limit equilibrium mechanics model and the formula of theory of suspension,the length of bolt was determined 1.7m,with 100mm×100mm of metal mesh,thickness of 80~100mm sprayed concrete,the bolting-wire mesh-shotcreting support of whole section was used.Roadway deformation was simulated using FLAC3 Dunder different lateral pressure coefficient,when the lateral pressure coefficient is to 2.5,its roadway deformation degree matches the transportation roadway actual destruction process and destruction degree in nine-plate ore body.Numerical simulation shows that the distribution more uniform has no obvious stress concentration phenomenon,displacement of roof and two sides are significantly reduced after supporting.And the use of convergence monitoring in ten-plateore body constructing roadway.Over time,the displacement in roof and the two sides tend to converge.The displacement of each monitoring point in roof converge at 10~20mm,the displacement between two sides converging to 11~20mm,the closer shod the smaller the amount of displacement of the roadway surface.The roadway section and the supporting method of optimization can effectively control the roadwaydeformation and failure in Wafangzi manganese ore mine.