Study on compressive strength change law of surrounding rock after water absorption in mine deep soft rock roadway

In order to obtain the main causes of the serious mine roadway deformation and failure occurred by the water absorption softeningand strength reduced of t he surrounding rock in the deep soft rock roadway,based on the deep soft rock roadway of Nanshan Mine in He-gang Mining Area as an engineering background,with the si te sampling of the typical surrounding rock in the mine roadway,the authorsconducted the rock indoor water absorption test and strength softening test. The experimental re sults showed that the water absorption curveof deep sandstones in Nanshan mine could be divided into three stages,the rapid growth stage ,nonlinear slow growth stage ,an d the con-stant growth stage. The rock softening was obvious with the growth of water absorption and the tested strength curve had three stages,name-ly the sharp decay, slow decay and constant decay stage. The fitting curves showed the exponential relation between strength softening andtime of water absorption,which would provide theor etical basis for the further study on mechanisms of deformation failure and stability con-trol countermeasures to deep soft rock tunnel during excavation.