Study on Shear Creep Characteristics of Soft Interlayer under Periodic Disturbance
The study of creep characteristics of rocks under the influence of dynamic disturbance effects has always been a hot and difficult issue in the fields of geotechnical and mining,seriously affecting the safety and stability of slopes and under-ground geotechnical engineering.To study the shear creep characteristics of weak interlayers(carbonaceous shale)under the influence of periodic disturbance effects,graded loading shear creep tests were conducted on weak interlayers under different disturbance cycles to obtain the influence of periodic disturbance effects on the shear creep characteristics of weak interlayers.Based on improved Kelvin body and viscoplastic body(considering damage variable D and accelerated creep threshold τs),a new type of shear creep model for weak interlayers under the influence of periodic disturbance effects was constructed by intro-ducing disturbance induced sudden deformation elements.The study results show that:① with the extension of the disturbance period,the graded shear creep strain value and cumulative shear creep strain value of the weak interlayer gradually increase,and the total creep duration shows a significant decreasing trend,and the ductile failure characteristics are enhanced;② As the disturbance period increases,the deceleration creep time of the weak interlayer becomes longer,and the steady-state creep rate fluctuates and the degree of fluctuation continues to increase;After the weak interlayer reaches or exceeds the failure level shear stress,its creep rate first decreases,and then gradually approaches zero;③ Based on the shear creep characteristics of the soft interlayer,the Levenberg-Marquardt optimization algorithm was adopted to determine the model parameters and verify the reliability of the creep model.
periodic disturbanceweak interlayercreep characteristicconstitutive model
万方数据
维普
