单裂隙辐射流节理面破坏过程水-力耦合研究

为研究单裂隙辐射流受外力和渗流力作用破坏过程的水-力耦合特性,采用预制柱形节理试件进行试验,并结合数值模拟进行综合分析。结果表明,节理破坏包括剪切接触和损伤滑移摩擦2个阶段,法向压力增大引起剪应力增大和裂隙开度减小,剪应力存在连续波动的波峰与波谷,优势水力通道的"U"形分布范围出现小幅扩散;水压力能缓冲节理破坏并带走细小颗粒,增大等效渗透系数,提升裂隙渗透能力,入口水压力增大引起剪应力减小;碎屑充填物主要分布在优势水力通道范围之外,既能影响裂隙的渗透能力,又在一定程度上作为缓冲区保护节理面不被继续破坏。

Study on Hydraulic Coupling of Failure Process of Joint Surface in Single Fracture Radiation Flow

To study the hydraulic coupling characteristics of the failure process for single fracture radiation flow under the action of external force and seepage force,the precast column joint specimens are used for experimental study,and the test results are compressively analyzed combined with numerical simulation.The results show that,(a)the joint failure includes two stages of shear contact and damage slip friction,the increase of normal pressure leads to the increase of shear stress and the decrease of crack opening,which has continuous wave crest and trough of shear stress,and the U-shaped distribution range of the dominant hydraulic channel has a small diffusion;(b)the water pressure can buffer joint failure to take away small particles,increase equivalent osmotic coefficient and improve fracture permeability,and the increase of inlet water pressure will cause shear stress to decrease;and(c)the debris fillings which is mainly distributed outside the scope of the dominant hydraulic channel not only affect the penetration capacity of fractures,but also act as a buffer zone to protect the joint surface from further damage.