A Comprehensive Classification Method for the Pore Permeability of Deep-Mine Sandstone Used to Guide Grouting

One type of seepage water that is difficult to plug by grouting the exuding through pores sandstone in deep underground engineering. Aiming at this problem, paper collected deep-mine samples from Southwest Shandong coalfield, studied pore structure and its influential factors casting thin slices, scanning electron microscopy, mercury intrusion physical property tests, selected five representative permeability classification indicators: permeability, porosity, average throat radius, comprehensive diagenetic coefficient sorting coefficient. According these indicators, all was divided into four subcategories (I1, I2, II1, II2) perspective grouting. I1 has medium throats can be filled with ultrafine cement-based slurries; I2 medium-small fine throats; II1 or small microthroats; both chemical II2 micropores microthroats cannot grouted. This case study provides a reference for evaluation lays foundation classified permeation subsequent pore-expanding