Study on the Constitutive Model of Rock Creep under High Stress State
In order to investigate the constitutive problem of rock creep damage under high stress condi-tions,creep tests at different stress levels are conducted.A new damage expression is proposed through theoretical analysis,and the creep parameters are corrected.A creep constitutive model considering the damage process is established,and the parameter rules of the model are analyzed according to the experi-mental results.The results show that under high stress conditions,with the increase of stress,the initial damage caused by rock during monotone loading is 0.21,0.31 and 0.4,respectively,corresponding to creep life,which decreases with the increase of the creep stress level.The new model can reflect the three-stage characteristics of creep strain better,especially in the steady-state strain growth trend,which is more con-sistent with the test results,with the correlation coefficients not less than 0.98.The elastic modulus and viscoelastic coefficient of the creep section both show a nonlinear decreasing trend of first increasing and then decreasing slowly with the increase of stress ratio.
万方数据
维普
