Creep constitutive model of cemented body used in backfilling mining

In order to analyze the creep properties of cemented body used in backfilling mining,triaxial creep experiments were conducted.Based on these,the damage evolution equation considering time and stress was deduced,and damage variable was brought in modified Nishihara model,and the new constitutive model was established and the 3D creep equation of backfilling cemented body was deduced.The creep model parameters were integrated based on the experiment data,and the comparative analysis of creep curves in theory and on experiment was conducted.The findings show that backfilling cemented body is viscosity elastic-plastic material and has obvious rheological characteristics,there are only decay creep and steady-state creep when deviatoric stress is small,when it is big,there is accelerated creep.Creep amount increases with the increasing of stress,but increase rate is weakened.It shows that the modified Nishihara model considering damage can better reflect the creep law of backfilling cemented body.