Recognition of creep model of layer composite rock mass and its application

The layer composite rock mass is composed of soft rock and hard rock. The difference of their mechanical characteristics is obvious. So it is difficult to describe comprehensively the complicated property with the existent constitutive model. Based on the creep properties of soft rock and hard rock in the composite rock mass and the creep experiment curves, the creep model was used by connecting Burgers model in series with a plastic component. The creep curves of the composite model under diverse stress levels were attained by multi-staged loading. The simulated result was proved to be good by comparing the theoretical curves and the experimental curves. The rheology principium of the complicated rock mass was illuminated well by the model so that it can be popularly used in engineering practice.