Study on Transmissivity of Shattered Fault Zone Under Ground Pressure

For studying transmissivity of fault zone filled with shattered rock,a simulation experiment was designed under the conditions of actual ground pressure and seepage force.Three sets of samples were collected in mine roadways,which were pure sandstone,sandstone mixed mudstone by 2∶1,and sandstone mixed mudstone by 1∶2.The permeability coefficient was calculated by measuring seepage velocity.The result shows that the higher composition of mud in shattered rock will result in the lower permeability coefficient under same conditions.The permeability coefficient of shattered rock presents non-linear inverse proportion with seepage force under the same underground pressure.It is concluded that the clay mineral contained in shattered rock of fault zone will result in the rock sopping up the water and being swelled and intenerated,which will block groundwater seepage.Otherwise,the seepage force,which was brought to bear on rock sample quickly,makes the holes in sample be compressed and decrease permeability coefficient.The result of the experiment can be used to estimate the actual seepage characteristic of fault zone filled with shattered rock approximatively.It can explain the phenomenon reasonably that some fault’s transmissivity is very poor with high confined water head in some mines.