基于颗粒流程序的矿区重载下级配碎石分析

为了研究矿区重载作用下级配碎石的细观力学响应,利用颗粒流程序构建了不同厚度级配碎石的矿区道路细观结构,在施加矿区典型矿车荷载条件下,追踪了道路结构内部颗粒的接触力、位移变化情况,并监测了荷载作用下级配碎石底部平均应力、轮胎中间竖向位移.结果表明:施加重载后,细观模型内部的接触力网和位移矢量出现各向异性,主要分布于荷载下方,随着深度的增加,荷载的影响逐渐减小;在厚度为40 cm时测量圆1和测量圆3的配位数最大,测量圆2在45 cm时配位数出现最大值;随着厚度的增加,XX和YY方向平均应力基本呈增加的趋势,在45 cm处出现峰值;最大接触力和平均接触力的最大值所对应的厚度分别为45 cm和40 cm;左右轮胎中间竖向位移在厚度为45 cm时出现最小值;矿区重载级配碎石层的推荐厚度为40～45 cm.

Analysis on Graded Broken Stone Under Overload in Mining Area Based on the Particle Flow Code

In order to research the mesomechanics responses of graded broken stone under overload in mining area, the road mesostructure of graded broken stone with different thickness was constructed using the Particle Flow Code. The changes of contact force and displacement among the particles in road structure were traced under the typical mining car loading condition, and the mean stress at the bottom of graded broken stone and the vertical displacement in the middle of tires were monitored under the overload. The results show that the contact force network and displacement vectors become anisotropic after applying the overload in the mesoscopic model, which mainly distribute under the load, and the influence of overload decreases as the increase of depth. The coordination numbers of measurement circle 1 and 3 have the maximum values with the thickness of 40cm, and the coordination number of measurement circle 2 has the maximum values with the thickness of 45cm. The mean stresses of XX and YY direction increase with the increase of thickness basically, and their peak values appear at 45cm. The maximum values of the maximum contact force and mean contact force correspond to the thickness of 45cm and 40cm. In addition, the vertical displacements in the middle of left and right tires have the minimum values at the thickness of 45cm. Finally, the recommended thickness of graded broken stone layer under overload in mining area is 40cm~45cm.