多向荷载作用下隔离矿柱采场矿壁受力分析

Stress analysis of mine wall in panel barrier pillar-stope under multi-directional loads

为确定梯形侧向荷载和垂直荷载共同作用下矿壁的应力分布,基于弹性力学平面应变假设,建立矿壁力学模型进行应力求解。通过模型分析,确定矿壁合理宽度,分析可能发生破坏的形式,提出矿壁稳定性的控制措施。研究结果表明:初始侧向荷载q对水平应力、垂直应力和剪应力均有影响,初始垂直荷载P0只影响垂直应力;水平应力最大值和最小值不随宽度改变而改变;剪应力沿矿壁中心轴呈对称分布,在中心位置达到最大值。当矿壁宽度较窄时,在充填体一侧会出现拉应力,在矿壁的采空区侧的底端出现垂直压应力最大值。结合冬瓜山工程实例,计算出矿壁宽度需大于3.5 m,现场工程选择4 m宽矿壁进行开采,矿壁稳定性较好。

In order to determine the stress distribution of the mine wall under the trapezoidal lateral load and vertical load,a mechanical model of the mine wall was established and analyzed based on the elastic plane strain assumption.Using the model,the reasonable width of the mine wall was determined,the possible forms of failure were analyzed,and the controls related to the mine wall stability were proposed.The results show that the initial lateral load q affects the horizontal stress,the vertical stress and the shear stress,and the initial vertical load P0only affects the vertical stress.The maximum and the minimum of horizontal stress do not change with the width.The shear stress is symmetrically distributed along the central axis of the mine wall and the maximum appears in the center of the mine wall.When the mine wall is small,the tensile stress appears on the side of filling body.The maximum vertical compressive stress appears at the bottom on the side of the cavity.According to the cases of Dongguashan copper mine,the width should be more than3.5m.The mine wall with4m in width is selected for on-site engineering,and the mine wall stability is in good condition.