Layered Rocks Dip Experimental Investigation

Sedimentary rock mass which have a layered structure account for two-thirds ofthe land area in nature,while in China, rock has a layered structure is widely distributedthroughout the country,as a consequent,people encounter a lot problems of layered rockmass stability in the underground construction. Because of the layered structure,thestrength and deformation properties of layered rock mass have obvious character ofanisotropy, also rock mass failure mechanism and destruction are significantly differentfrom other rock mass. In nature, the angle between the bedding plane tilt direction of thenatural formed layered rock and the tendency of the rock mass generally exists.Themechanical properties of layered rock in the direction of each bedding planes is roughlythe same, but a greater difference exists. in the mechanical properties between paralleland perpendicular direction level, this difference causes the anisotropic characteristicsof the layered rock mass Generally, the strength of the anisotropic rock material have asignificant angle effect varies with the change in the direction of level inclination,andthe failure mode of the anisotropic rock material is directly related to level inclination.To study the effect of the inclination of the layered rock, determine its structurecharacteristics, deformation parameters and strength characteristics of layeredsurrounding rock reasonably,find its impact on the stability of the layered rockunderground cavern,this article use combining method of theoretical analysis-laboratory tests,start with the theory, study the structural characteristics,the anisotropyand transversely isotropic characteristics of the layered rock mass, then analyzes thedeformation theoretical solution and strength criterion of layered rock mass underdifferent levels inclination. finally achieve a conclusion that how the angle of principalstress and the bedding planes affects in the deformation and strength. characteristics ofthe layered rock mass.The main research achievements are:(1) Based on a simplified theoretical model deduced layered rocks dip at differentlevels under the parameters of the mechanical properties of the theoretical solution;(2) Use shale as the research object, has been uniaxial and triaxial compression testconditions layered rock strength, elastic modulus, Poisson’s ratio and other mechanicalparameters of the variation;(3) Acheive shale failure modes under uniaxial and triaxial conditions at different levels dip bedded.