Abstract:

The uniaxial tensile test of loess shows that the tensile strength of loess is very small; and under the action of tensile stress, the burst brittle rupture will occur on loess sample, with the coarse fracture plane and the direction vertical to tensile stress. By using the numerical analysis software RFPA, the whole tensile fracture process of loess is simulated; and the expansion and evolution of internal cracks in loess under the action of tensile stress is captured. The results indicate that the tensile fracture course of loess can be divided into two stages, one is the linear deformation stage, and the other is the stage of formation, expansion and evolution of cracks in loess, which can be completed in very short time. So the broken of loess under the action of tensile stress is paroxysmal, which belongs to a brittle fracture. The result of uniaxial tensile test on loess is very consistent with that of the numerical simulation analysis.

Key words: tensile stress, brittle fracture, fracture process, crack, simulation analysis