多放矿口间的矿岩颗粒均匀流与应力演化规律

针对当前多口放矿研究中存在的放矿口间距阈值和应力分布等问题，基于刚性块体模型开展不同放矿口间距和放矿方式条件下的放矿数值试验，对多放矿口间的矿岩颗粒均匀流与应力演化规律进行量化研究.研究结果表明:多口放矿条件下能够产生矿岩颗粒均匀流的放矿口间距阈值介于1.0~1.25倍的松动体最大宽度.矿岩颗粒流动体系内存在明显的应力拱效应，放矿过程中松动体上方的垂直应力会逐渐向两侧非松动区域转移.在所研究的取值范围内，采场底部最大垂直应力已接近初始垂直应力的1.8倍.放矿过程中采场内非松动区域的配位数约为8~9，且空间高度越低其配位数越大;在松动区域内越接近放矿口的位置，其矿岩颗粒越松散且运移与接触变化的无序程度越高.

Uniform Flow and Stress Evolution Laws of Caved Ore and Rock Partides Between Multiple Drawpoints

Aiming at the problems such as the threshold of drawpoint spacing and stress distribution in the research of multiple draw interaction， numerical tests based on the rigid block model were carried out under the conditions of different drawpoint spacings and draw modes， and uniform flow and stress evolution laws of caved ore and rock between multiple drawpoints were quantitatively studied. The results showed that the threshold of drawpoint spacing that produces uniform flow of caved ore and rock lies between 1.0 and 1.25 times of the maximum width of the isolated movement zone under the condition of multiple drawpoints. There is an obvious stress arching effect in the particle flow system， and the vertical stress above movement zones gradually transfers to the immobile zones on both sides during the draw process. The maximum vertical stress at the bottom of stope is nearly 1.8 times of the initial vertical stress within the range of values studied. The coordination number within the immobile zones is about 8~9 during the draw process， and the lower the space height， the larger the coordination number is. Within the movement zones， the closer to the drawpoints， the looser the caved ore and rock are， and the more disordered the migration and contact variations among particles are.