切顶卸压自成巷的连续-非连续方法模拟及切缝倾角的影响*

为克服利用连续方法或非连续方法模拟切顶卸压自成巷过程的不足，采用自主研发的适于模拟连续介质向非连续介质转化或非连续介质进一步演化的拉格朗日元与离散元耦合连续-非连续方法，提出基于高斯求积公式的势接触力计算方法以提高计算效率，通过考察剪裂纹和拉裂纹的时空分布和煤层支承压力的演化规律，研究不同切缝倾角时切顶卸压自成巷过程，并考虑右巷(胶运巷)的锚杆原始支护、锚索补强支护和液压元件的临时支护。研究结果表明:切缝倾角越大，右巷顶板完整性越好，这是由于当倾角较大时切缝尖端发展出的裂纹促进采空区顶板冒落，从而阻隔采场压力向右巷顶板传递；左巷顶板的冒落越严重；切缝倾角以10°为宜。

Continuum-discontinuum method simulation of roadway automatically retained by roof cutting and pressure release and influence of cutting seam inclination angle

In order to overcome the shortcomings of the continuum or discontinuum methods in simulating the processes of roadways automatically retained by roof cutting and pressure release,the self-developed combined Lagragian-discrete element method was used,which is suitable for simulating the transformation from continuum medium to discontinuum medium or the further evolution of discontinuum medium.Herein,a method for calculating the potentical contact force based on the Gauss quadrature formula was proposed to improve the computational efficiency.The spatiotemporal distributions of shear and tensile cracks and the evolution law of the abutment pressure of coal seam were examined,and the processes of roadway automatically retained by roof cutting and pressure release under different cutting seam inclination angles were studied considering the original support of bolt,the reinforcement support of anchor cable and the temporary support of hydraulic components in the right roadway.The results showed that the larger the cutting seam inclination angle,the better the integrality of roof in the right roadway,which was because when the inclination angle was larger,the cracks developed at the tip of cutting seam promoted the roof caving in the goaf,thus blocked the transfer of stope pressure to the roof of right roadway.The roof caving in the goaf in the left roadway was more serious,and the appropriate cutting seam inclination angle was about 10°.