With phyllite of Shuangqiaoshan Group in a mine as the research object,this paper studied creep characteristics and theoretical model of phyllite under different normal stresses.The result shows that,mechanical parameters such as shear modulus have obvious timeliness.With the increase of time,the shear modulus decreases rapidly and tends to be stable.Furthermore,under the premise of constant time,the normal stress is large and the decreasing trend is relatively small.Considering the creep damage developed in rock,a damage variable varying with normal stress and time is introduced to build a non-linear creep damage Nishihara model.On this basis,a non-linear dashpot element with strain trigger is adopted to derive the creep equation of the improved Nishihara model.The model equation is fitted with experimental data to carry out parameter identification and comparative analysis,which manifests that the model is reasonable and feasible in characterizing the deformation characteristics of phyllite creep at different stages under different normal stresses.
维普
万方数据