Study On Creep Behavior Of Fractured Hard Rock Under Disturbance Load

During the excavation of the caverns,excavation disturbances such as stress release transfer and blasting can cause damage to the surrounding rock,and its long-term stability will be a concern.Combined with the three – steped recovery mining of a metal mine,a typical ore-marble and the creep disturbance characteristics under the condition of single hole are analyzed to analyze the long-term stability of the Isolated ore wall under multiple disturbances.1.The disturbance creep test of marble with different diameter holes was carried out by SHPB impact experimental system.The disturbance creep compression test of marble with different pore size is carried out by using graded loading method and gravitational loading after creep for a period of time.It is found that the pore size of the marble is different,and the long-term strength of the marble is also changed.The single-axis compression disturbance creep test was carried out on the marble with the same hole size with different impact load size.It was found that the greater the disturbance load,the smaller the rock load,That is,the size of the disturbance load rock creep characteristics of a great impact.2.According to the creep curve characteristics of the voided marble under the disturbance load,the basic elements and the combination of the holes in the creep model are analyzed and identified,into the Burgers model which can describe the instantaneous elastic deformation,decay creep deformation and constant velocity creep deformation.The creep test curves of the D-6 porosity marble and the two parameters in the Kurgvin body in the Burgers model are fitted according to the Burgers model constitutive equation by using the least squares method in MATLAB,the creep parameters of the D-6 hole marble at each stage load and before and after each disturbance were obtained.The experimental curve and the theoretical curve have good similarity,which shows that the perturbation creep characteristics of the hole marble are described by the Burgers model and the parameters in the Kelvin body.3.Based on the results of indoor perturbation creep test,the numerical simulation of marble with 8mm aperture was carried out,and the dynamic calculation module was introduced on the basis of static load creep module.The creep simulation curves of uniaxial compression perturbation are in good agreement with the indoor test curves.