Experimental Study On Uniaxial Compression And Rheological Characteristic Of Sandstone Containing Coplanar Pre-existing Fissures

The complexity of existing environment and load effect, rock deformation and buckling failure are serious harming the play of infrastructure’s functions, and also becoming a danger to people’s lives and properties. Therefore, combining with the complexity of rock fabric and considering of the rock rheological characteristic under the action of long-term load are very necessary for the construction of rock engineering.This paper is supported by the Natural Science Foundation of China(No. 41172243): the rheological and propagation mechanism of the unloading fracture hard rock under high residual stress. Based on the study of uniaxial normal load, analyzed the influence of geometrical characteristic, stress level and cyclic loading period for rock rheological by the uniaxial long-term compression test of different loading ways of the rheological. These research results are meaningful for the rock stability and deformation assessing.In this paper, main tasks are as follows:① Based on uniaxial normal load test,this paper analyzed the basic mechanical properties of different geometric characteristics and compared the difference of failure and deformation of rock samples. On this basis, intact and pre-crack rock samples macroscopic collapse modes have been summarized.② Based on uniaxial creep test, this paper analyzed creep property of different geometrical characteristics and comparison of the rheological characteristic for the difference of stress level and geometrical characteristic.③ Based on uniaxial cyclic creep test, this paper analyzed deformation behavior, deformation process and hysteretic property of rock samples. On this basis, this paper also analyzed rheological behavior under the change of lower stress level and test cycle. Finally, this paper also analyzed failure characteristics of rock sample under the cyclic creep test.④ Based on the uniaxial rheology test of rock samples containing 35 o pre-existing coplanar fissures, this paper compared of the phase characters for the change of strain or strain rate under two rheology test method and analyzed the reason of deformation increases of the rock samples.