垮落矸石注浆充填体压实特性的颗粒流模拟

利用PFC计算程序建立了垮落矸石充填体的颗粒流模型，通过颗粒流数值模拟试验，再现了煤层采出、顶板垮落、注浆充填、充填体压实整个动态发展过程.通过改变模型中颗粒数目、接触刚度和法向刚度等细观参数，研究了充填率、充填材料的胶结强度和弹性模量等宏观性质对充填体压实特性的影响.研究发现：充填率是影响充填体压实特性的最敏感因素，15％为试验模型的临界充填率，当大于15％时，充填体的压实曲线急剧改变；在相同充填率下，充填料的胶结强度决定充填体的结构屈服应力，是影响充填体压缩下沉量的关键因素，但对压缩下沉量极限值没有影响；充填率越小，弹性模量对充填体压实特性影响越显著.

Simulation of backfill compaction character by particle flow code

Based on Particle Flow Code(PFC),the particle flow model of backfill in caving area was constituted.By numerical simulation,dynamic process of grouting backfill in caving area,including coal mining,roof collapsing and filling were realized.By changing the number of particle,normal stiffness value and shear stiffness value in the model,the influence of filling ratio,cementation character and elasticity modulus on the compaction character was studied.The results show that filling ratio,if more than 15%,compaction curve of the model changes sharply,is the most sensitive factor influencing compaction character;in the same filling ratio,cementation strength is key factor influencing the quantity of compaction subsidence,but not influencing the limit value;the smaller the filling ratio is,the influence of elasticity modulus on the compaction character is more evident.