Experimental study on numerical simulation of creep characteristics for soft rock of similar model

The practice of using traditional materials to simulate soft rocks in similar model tests is challenging because of their characteristics of low strength, large deformations, and strong rheology. In this study, the authors developed a new type of similar material which took sand as aggregate and paraffin as cementation to produce the similar material specimen of shale. The advantages of this method were that the materials were easy to obtain, the cost was low, the specimen was simple to manufacture, the forming process was short, and the deformation was easily recognized. The creep tests of specimens with different proportions of sand under different axial compressions were carried out. The numerical analysis of a soft rock roadway with this material was conducted in ABAQUS. The results showed that the creep characteristics of the specimens with this type of similar material were consistent with typical rocks. The steady creep and axial strain were both in proportion to the axial compression and inversely proportion to confining pressure. Roof shedding and floor heave were likely to occur in soft rock roadways built by this material, also the same for site-engineering conditions. This paper provides useful references for the study of stability of deep soft rock roadway and the support of the roadway using the similar material method.