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.
ZHANG Wen-quan, YUAN Jiu-dang, WANG Zhong-chang, ZHU Ji-ming,
. An experimental study on compressive shear seepage laws of mining-induced fractured rock mass[J]. Rock and Soil Mechanics, 2017
, 38(9)
: 2473
-2479
.
DOI: 10.16285/j.rsm.2017.09.002