刚度差异对岩石破裂影响的颗粒流模拟研究

Influence of stiffness difference on rock fracture based on particle flow simulation

为研究矿物颗粒与胶结物刚度差异对岩石破裂的影响,基于平行黏结模型开展了不同颗粒有效模量、黏结有效模量下的压缩、拉伸试验研究。结果表明:颗粒有效模量与压弹性模量相关性最大,黏结有效模量与拉弹性模量相关性最大,同时受黏结有效模量影响的宏观参数包含且多于颗粒有效模量,优先标定黏结有效模量有助于提高模拟试验的准确性。固定黏结有效模量时,颗粒有效模量越大,岩体稳定性越好;固定颗粒有效模量时,黏结有效模量越大,颗粒稳定性越差;当两种有效模量增大时,模型易出现脆性破坏,反之易出现塑性破坏;刚度差异系数值反映了模型内部颗粒刚度和胶结体刚度的差别,刚度差异系数值越小,模型越容易产生裂隙,即矿物颗粒的刚度越大岩石越稳定,胶结物的刚度越大岩石越容易出现裂隙。最后利用试验实例验证了结论的准确性。

In order to investigate the influence of differences in stiffness between mineral particles and cement on rock fracture,this paper carries out a study of compression and tension tests under effective modulus of different particles and effective modulus of cement based on the parallel bond model.The results show that the effective modulus of particles is the most correlated with the elastic modulus under compression and the effective modulus of bond is the most correlated with the tensile elastic modulus.The macroscopic parameters affected by the effective modulus of bond include and are more than the effective modulus of particles.When the effective modulus of bond is fixed,the greater the effective modulus of particles is,the better the stability of the rock mass becomes.When the effective modulus of particles is fixed,the greater the effective modulus of bond is,the less stable the particles become.When the effective modulus of the two types of particles increases,the model is more prone to brittle damage and vice versa.The value of the coefficient of stiffness difference reflects the difference between the stiffness of the particles and the stiffness of the bond within the model.The smaller the value of the coefficient of stiffness difference is,the more likely the model is to produce.The smaller the value of the coefficient of difference in stiffness is,the more likely the model is to fracture.In other words,the greater the stiffness of the mineral particles is,the more stable the rock becomes;the greater the stiffness of the cement is,the more likely it is to fracture.Finally,the accuracy of the conclusions is verified by test examples.