Fig. 12

The changing rate under different resting frequency. The differences in the changing rate of axial effective stress and pore pressure under different resting frequency were significant, and the rest parameters did not exhibit obvious differences. Because the coordinate axis scale of radial displacement was small, a large difference in radial displacement between Grade 2 and 3 was displayed; actually, both of the maximum changing rates were less than 5 % from case 1 to 4 for these two models. a The axial effective stress in the center of nucleus, b The axial effective stress in the posterior annulus region, c The pore pressure in the center of nucleus, d The radial displacement, e The fluid loss