应力—渗流耦合作用下损伤岩石渗流特性

地下矿产资源开采过程中,频繁的应力扰动会对深部硬岩造成一定的损伤.硬岩内部孔隙和裂隙在高地应力和高渗透压的状态下迅速扩展贯通,严重威胁岩体工程的安全和稳定性.针对损伤花岗岩开展了一系列应力—渗流耦合试验,结合CT扫描,考虑渗透压、围压和损伤程度等因素的影响,综合分析了损伤岩石在应力—渗流耦合作用下的力学和渗流特性.试验...

Seepage Characteristics of Damaged Rock Under Stress-Seepage Coupling

During the mining of underground mineral resources，the deep hard rock will be damaged by the frequent stress disturbances.Its internal pores and fissures will rapidly expand and penetrate under the state of high ground stress and high osmotic pressure，which seriously threatens the safety and stability of rock mass engineering.The damage degree D is defined by the ratio of axial stress σ to compressive strength σ_c.Pre-damaged rock samples with different damage degrees （0%，25%，40%，50%，65%，75%，100%） were prepared by uniaxial compression test.A series of stress-seepage coupling tests were carried out for 75% damaged granite.Combined with CT scanning，considering the influence of seepage pressure，confining pressure and damage degree，the mechanical and seepage characteristics of damaged rock under stress-seepage coupling was comprehensive analyzed.The research results show that with the increase of damage degree，the number and size of pore and fracture of rock sample increase significantly，and changes of the volume of pore and fracture of rock sample shows a trend of increase gently and increase steadily to increase sharply.Under the same confining pressure，the peak strength of the rock sample shows a linear decrease with the increase of osmotic pressure，the osmotic pressure has a significant weakening effect on the strength of damaged granite，and the degree of weakening is independent of the confining pressure.The permeability of pre-damaged rock samples is closely related to the volume of pores and fractures.The variation trend of permeability with damage percentage confirms the evolution law of pores in different development stages.The greater the degree of damage，the higher the degree of fracture development and the greater the permeability.At the same time，the permeability can be characterized by the degree of development of pores and fractures.With the same degree of fracture development，the greater the confining pressure，the smaller the permeability.