Study on shear performance and fracture law of rock with primary cracks under influence of water infiltration
Primary fissures and water bodies will change the physical and mechanical properties of rocks and easily induce geological disasters.Therefore,the instability and failure behavior of rock mass under the action of water-fracture has become one of the important research contents in the field of underground geotechnical engineering.Based on the D-P criterion,the critical conditions of fracture fail-ure of fractured rock under different water content conditions were put forward,and the possible development and expansion of new cracks in rock under the influence of primary cracks were analyzed.The shear test of water-bearing red sandstone was carried out.The results show that within the scope of this test,the water-bearing fracture rock sample and the prefabricated primary fracture evolve in a segmented manner with a 20°angle as the boundary.With the increase of fracture dip angle,the evolution trend changes from positive correlation to negative correlation,and the shear strength of water-bearing fracture rock sample is the largest at 20°.With the increase of water content,the increment of water infiltration on the weakening degree of shear performance damage of rock samples decreases.After the water content is 1.213％,with the continuous increase of water content,the weakening degree of shear performance damage of rock samples decreases from increase to decrease.It can be seen that the weakening degree of saturated water content on the damage of frac-tured rock samples is less than that of unsaturated water content.The failure mode of the shear failure surface shows a trend of shear failure-shear failure dominated tensile-shear composite failure-tensile-shear composite failure-tensile failure dominated tensile-shear composite failure.The research results can provide reference for the study of water inrush accidents induced by rock failure under the in-fluence of multiple factors.
rock mechanicsfailure criterionwater infiltrationprimary cracksstrength damage weakening
万方数据
维普
