考虑采空区压实度的端面顶板稳定性数值模拟

Numerical simulation on the tip-to-face roof stability considering goaf compaction

为研究不同采空区压实度条件下端面顶板稳定性,通过PHASE 2D有限元软件建立高刚度和低刚度2个采空区数值模型,研究端面顶板下沉规律、支承压力分布特征及端面顶板塑性区演化。研究结果表明,当采空区刚度为250 MPa时,开采前后直接顶下沉量最大值分别为90 mm和109 mm;当采空区刚度为600 MPa时,开采前后直接顶下沉量最大值分别为43 mm和74 mm;当采空区刚度由250 MPa增大至600 MPa时,工作面支承压力峰值由7.3 MPa降低为6.8 MPa;增大采空区刚度后,工作面端面顶板塑性区范围降低了44.3%。因此,有效提高采空区刚度能提高端面顶板稳定性,从而降低端面冒顶发生的概率。

In order to study the stability of the tip-to-face roof under different gob compaction,two numerical models including the high and low stiffness gob are developed using PHASE 2D finite element software.The vertical displacement of the tip-to-face roof,abutment pressure and the plastic zones on roof are obtained.The results show that:when the gob stiffness is 250 MPa,the maximum roof displacement before and after mining are 90 mm and 109 mm,respectively,compared to 43 mm and 74mm for a 600 MPa gob model.The abutment pressure peak is decreased from 7.3 MPa to 6.8 MPa when the gob stiffness is increased from 250 MPa to 600 MPa.The plastic zone on roof is reduced by 44.3%when the gob stiffness increases.Therefore,the roof stability can be improved if the gob stiffness is high,thus reducing the roof cavity.