Change law study on cut-through fracture seepage properties of slate in corrosion environment

As the law of slate fissure seepage characteristics affected by chemical corrosion is unclear,a seepage char- acteristic experiment of slate cut-through fracture in hydrochemical solutions ( NaCl, HCl, NaOH) environment in Dalian area was conducted in this study. By comparing the SEM scanning and solution’s pH,the microscopic structure mechanism of fissured slate influenced by water-rock interaction was first analyzed,and the changing law of permeabil- ity coefficient under different steeping times was obtained macroscopically. And then,the test results were contrastively analyzed based on a series of chemical reaction equations. Test results show that:hydrochemical corrosion has a signifi- cant effect on the permeability of fissured slate. HCl and NaCl solutions play an important role in corroding structural plane,and have the average gap width increased;however,the stable precipitation materials resulted from NaOH solu- tion-slate reaction and adhered between slates gaps have the average gap width decreased. With establishing the non- linear relationship of permeability coefficient under different solutions and steeping time,and introducing the relevant theoretical formulas to compile the seepage-chemical-stress coupled calculation program of FLAC3D fish language,the experiment was numerically simulated. There is a good agreement between the calculation result and the experiment re- sult.