基于岩体时变力学参数的深部矿段回采顺序优化

Optimization of mining sequence based on rock mass time-varying mechanics parameters

基于岩体力学的时变参数演化规律,设计高峰深部矿段5种可行的回采顺序方案。运用耦合建模技术构建深部矿段复合空区的三维有限元模型,再采用FLAC3D仿真技术,实现岩体时变力学参数下不同回采顺序的时空演化规律。研究结果表明:各种回采顺序下的局部岩体最大拉应力和压应力都达到岩体的抗拉和抗压强度,应及时处理采空区;随着回采推进,顶底板位移逐渐增大,在最后1步达到最大值,并且受不同工艺的影响,最大位移表现出差异性;顶板位移最大沉降分别为50.0,38.0,74.0,64.9和70.5 mm,底板最大垂直位移(底鼓)分别为68.6,34.9,47.6,45.8和46.4 mm;岩体的破坏主要表现为剪切和拉伸塑性破坏,其中方案3和方案4的剪切破坏体积比方案1,2和5的剪切破坏体积,方案5发生拉伸破坏体积最大,方案2的整体塑性区体积比方案1的稍大。综合采场的生产能力和形变应力及其塑性破坏特征分析,选择较优的方案2。

Based on the time-varying parameter evolution law of rock mass mechanics,five kinds of mining sequence schemes were designed in the deep section of Gaofeng mine.The3D finite element model with the goafs was built by the coupled modeling technique in deep mine sections.Using the FLAC3D program,the evolution laws of space and time were simulated to different mining sequences based on the time-varying mechanical parameters of rock mass.The results show that the maximum values of tensile and compressive stress reach the tensile and compressive strength of rock mass.In order to ensure safety of the mining,the goafs should be handled in time.With the mining process,the displacement increases gradually in the roof and floor.The displacement reaches the maximum in the last step.In the five cases,the maximum subsidences of the roof are50.0,38.0,74.6,64.9and70.5mm,and the maximum vertical displacement of the floor is68.6,34.9,47.6,45.8and46.4mm,respectively.The plastic failure is mainly manifested in shear and tensile failure to the rock mass.For the plastic volume,the volumes of the shear failure of cases3and4are larger than those of the cases1,2and5;the volume of the tensile failure of case5is the largest;the volume of case2is slightly more than that of case1.For comprehensive production capacity,deformation,stress and plastic damage characteristics of stope,the case2is the best.