Study On The Rheological Properties Of Sandstone With Slanted Weak Structural Surface

In this paper,the stress and strain curves,failure modes,strength,modulus of elasticity,Poisson's ratio,creep rate and creep variable of the sandstone with weak intercalated weak intercalated sandstone are studied by uniaxial compression strength test and uniaxial compression creep test.The influence of the dip angle of the soft interlayer on the above physical quantities is summarized.The main contents are as follows:(1)The standard specimens of green sandstone with complete and weak intercalation of 15°,30°,45° and 60° were prepared,and the tests were carried out in the laboratory to obtain the parameters reflecting the internal mechanical properties of the rock samples,and to sum up the influence of different dip weak interbeds on the strength of rock.It is considered that the weak intercalation can weaken the uniaxial compressive strength,Poisson's ratio and elastic modulus of rock mass.(2)According to the parameters obtained by the strength test,the rheological test is designed by the uniaxial compression rheological test,and the rheological test is carried out by the cyclic loading and unloading method.The stress level and interlayer are studied by the rheological test under different load conditions of the rock mass with the weak interlayer and the inclined weak interlayer.The influence of the angle on the rheological properties of the specimen.It is found that the proportion of the creep strain in the total strain varies from 7% to 46%.It is considered that the model of the rheological failure is similar to the model of the strength failure.It is concluded that the soft intercalation can be the plastic property of the rock mass to enhance the weakening of the brittle properties.At the same time,it is concluded that the instantaneous strain,creep strain and total strain increase with the angle of the interlayer,and the transient strain,the transient strain,the viscoelastic strain and the viscoplastic strain also have the same trend,which indicates that the existence of the weak interlayer will cause the rheological deformation more easily,and the rheological deformation of the rock mass is increased with the increase of the dip angle of the sandwich layer.The greater the influence of stability,the more attention should be paid to the influence of weak intercalation on the rheology of rock mass.(3)Based on the rheological experiment data,the Boggs model is used to identify the whole creep curve of the uniaxial compression of the green sand with a 30 ° inclination angle.The parameters of the Boggs model are obtained,and the fitting effect is good.