Pore pressure evolution and mass loss of broken gangue during the seepage

Broken gangue consists of different particles, and it has more complicated seepage characteristics than intact rock sample. Using the self-designed instrument, the permeability, mass loss and pore pressure of crushed gangue during the seepage are tested. The result shows that: permeability parameter k of crushed rock has polynomial relationship with effective stress ’ in inverse proportion, and permeability parameter β of crushed gangue has power exponent relationship with effective stress ’ increasing in direct proportion. 8.0 – 10.0 mm particle size has a good support effect. Inner pressure of crushed rock is mostly linear distribution along the tube wall. After seepage，mass loss of broken gangue mainly increases with large particle size out of proportion.