Numerical Simulation Of Rock Friction And Sliding Under Dynamic Water Condition Based On UDEC

Rock friction sliding instability mechanism has been one of the hot research topics in rock mechanics and seismic dynamics.Widely concerned by scholars at home and abroad.In this paper,the sliding-holding-sliding test and the speed step test were carried out on the frictional sliding of rock by using discrete element software UDEC(Universal Distinct Element Code)and FISH language.The roughness,normal stress,water pressure,crack surface friction angle and other factors were studied on the rock.The influence of frictional friction reduction and healing amount on friction sliding.And reached the following conclusions:(1)Under different roughness conditions of the fracture surface,the frictional strength of the wet fracture surface is slightly lower than that of the dry fracture surface,and the friction strength of the wet fracture surface is greater than the friction strength of the dry fracture surface.Moreover,as the roughness of the fracture surface increases,the amount of friction reduction and the amount of healing increase.Both the friction strength reduction amount and the friction strength healing amount are time-dependent.(2)Under different normal stress conditions,the frictional strength reduction and the friction strength healing of the wet fissure surface are smaller than the dry fissure surface,and the frictional strength reduction and healing amount of the wet fissure surface and the dry fissure surface are both It decreases as the stress increases.The increase in normal stress inhibits the healing of the frictional strength of the rock.(3)Under different head pressure conditions,the friction strength reduction of the wet fissure surface decreases with the increase of water pressure.(4)Under the action of different crack surface friction angles,the frictional strength reduction and the friction strength healing amount of the wet fracture surface decrease with the increase of the friction angle of the fracture surface.(5)Under different thickness conditions of fault mud,the frictional strength reduction and the friction strength healing of the fracture surface decrease with the increase of the thickness of the fault mud.Under the different elastic modulus conditions of the fault mud,the frictional strength reduction and the friction strength healing amount of the fracture surface increase with the increase of the fracture clay elastic modulus.Under different strength conditions of fault mud,the frictional strength reduction and the friction strength healing of the fracture surface increase with the strength of the fault mud.