填充颗粒占比对砂岩破碎带突涌水通道形成的影响

Influence of Filling Particle Ratio on Water Inrush Channel in Sandstone Fracture Zone

隧道修建在穿过导水危险性断层时易发生充填体渗透破坏型突涌水。利用EDEM-Fluent耦合计算方法,探究了填充颗粒和骨架颗粒质量比例不同对突涌水通道形成的影响,考虑了固体颗粒间和流体-颗粒之间的相互作用以及流固耦合过程。研究表明,贯通突涌水通道的形成是由于填充颗粒的大量流失。模型中较高的填充颗粒质量占比使得颗粒平均粒径减小,骨架颗粒间接触数量减少,临界水力梯度提高。但当达到临界水力梯度后,在渗流力作用下填充颗粒更易涌出,颗粒流失速度和流失质量增加,骨架颗粒网络较为稀疏,最终孔隙率较大,形成的突涌水通道相对更为贯通。

The tunnel construction is prone to water inrush of filler infiltration damage when crossing a dangerous hydraulic conductivity fault. In this paper, the EDEM-Fluent coupling calculation method is used to investigate the impact of different mass proportions of filler particles and skeleton particles on the formation of water inrush channels. The formation of through water inrush channels is due to the massive loss of filler particles. High percentage of filler particles in the model could reduce the average particle size, decrease the number of contacts between skeletal particles and increase the critical hydraulic gradient. However, when the critical hydraulic gradient is reached, the filler particles are more likely to gush out under the action of seepage forces, the rate of particle loss and the loss of mass increase, the skeleton particle network is relatively sparse, the final porosity is larger, and the formed water inrush channel is relatively more connected.