ZHANG Wen-quan, YUAN Jiu-dang, WANG Zhong-chang, et al. An experimental study on compressive shear seepage laws of mining-induced fractured rock mass[J]. 2017, 38(9): 2473-2479.
DOI:
ZHANG Wen-quan, YUAN Jiu-dang, WANG Zhong-chang, et al. An experimental study on compressive shear seepage laws of mining-induced fractured rock mass[J]. 2017, 38(9): 2473-2479.DOI: 10.16285/j.rsm.2017.09.002.
An experimental study on compressive shear seepage laws of mining-induced fractured rock mass
According to the stress variation of fractured rock mass
the horizontal stress
vertical stress and water head pressure of mining stope were simulated by the normal load
shear load
and seepage water pressure during the mining process
respectively. In this study
the compression-shear seepage coupling experiment was conducted by using JAW-600 type shear seepage coupling testing system. Then the effects of normal load of fractured rock mass
roughness of joint
and seepage water pressure on the displacement
stress and permeability of specimens were discussed under the conditions of constant normal load (CNL) and constant normal stiffness (CNS). Besides
the influence laws of the shear displacement and dilatancy properties of fractured rock mass on shear stress
normal displacement
the hydraulic opening of joint and permeability were analyzed as well. It is shown that the hydraulic opening of fractured rock mass was promoted by shear stress and water head pressure
whereas its change was inhibited by the horizontal stress. Moreover
the hydraulic opening was divided into three phases
namely smaller or unchanged phase
increasing phase
stable phase with the change of shear displacement. It is found that the greater final stable value of hydraulic opening depended on the higher roughness of joint and the lower stiffness of fractured rock mass. In addition
the permeability firstly decreased and then increased owing to the dilatancy of fractured rock mass. The permeability increased with the increase of shear displacement and the roughness of joint surface
but decreased with the increase of normal load. Therefore
this study can provide the theoretical basis for the permeable channels
initiation and outbreak of permeability disaster evolution process in fractured rock mass.