| The frozen earth is wildly distributed in our country, mostly in west and north.As the gradually implementation of the national strategy, such aswestern-development and the revitalization of the old northeast industrial base, etc.,geological environmental problems will be confronted, such as frozen earth, frozenrockmass, when more and more highways, bridges, tunnels are builded.Now, many domestic and foreign researcher have studied the problem aboutfrozen rock and got gratifying achievement.While the joint, as macroscopic fracture,was not considered in the process of frozen rock researching, and the joint is commonin natural rock. So, this paper discusses the damage and failure mechanism on thebase of research of frozen-thaw cycling experiment and uniaxial compressionexprement, in terms of geometric features of joint （eg. inclination, degree ofbreakthrough, amount, thickness of joint）, filling, degree of saturation, cyclingnumber, started from making specimen containing joint. The main researchconclusion are as follows:(1) Compared with the intact rock mass, joint, as a macro crack, obviouslyincrease the damage of rock mass due to frozen-thaw cycling.(2) The factors of geometric features of joint （eg. inclination, degree ofbreakthrough, amount, thickness of joint）, filling, degree of saturation,cycling number make difference in position and development degree ofcracks, failure forms, material properties, uniaxial compression strength,elasticity modulus.(3) Experimental results show:Specimens damage worse, as amount or cyclingnumber increase, and become less brittle, more ductile; There are just jointhickness and water content, making specimens damage worst.(4) Fitting damage evolution equation of jointed rock, and importing it into thedamage constitutive model of uniaxial compression, establishing one whichconsidered the freeze-thaw damage. Compared with experimental curves,model curves is totyall consistent, although difference still exist. |
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