(1. State Key Laboratory for the Coal Mine Disaster Dynamics and Controls，Chongqing University，Chongqing 400044，China
2. State Key Laboratory of Geomechanics and Geotechnical Engineering，Institute of Rock and Soil Mechanics，Chinese Academy of Sciences，Wuhan，Hubei 430071，China)
Abstract：We carry out different angle shear tests and fatigue tests，to research salt rock compression-shear mechanical properties and crystal dislocations characteristics. Based on the damage mechanics theory，dislocation-damage relationship model is established. The main conclusions are：(1) Because that salt rock crystal dislocation slip resistance decreases，salt rock deformation resistance，peak stress and maximum deformation decrease with increasing shear deformation angle. (2) Fatigue life is associated with cyclic stress limit level. At different shear angles，if stress level is the same，the fatigue life is substantially the same. If the stress value is the same，the greater the angle，the shorter fatigue life. (3) Reverse shear influences hugely the fatigue life of rock salt，with more than 90% decrease. (4) Salt rock fatigue crack formation is related with movement of dislocations squeeze. Crack growth is the result of alternating slippage for multiple slip systems. The dislocation-damage model is established，so that the damage can essentially reveal the destruction process of salt rock. The greater the fatigue damage results in more obvious decrease of the carrying capacity.
2015, Vol. 34 
