Abstract: One of the effective aseismic reinforcement methods in rockfill dam is to improve the overall stability of rockfill at the upper part of the dam. Hence, a polyurethane foam adhesive (PFA) was firstly applied to reinforce rockfill materials, which can obviously enhance the shear strength and efficiently reduce the permanent deformation of the mixed material. A series of dynamic triaxial shear tests was conducted to investigate residual deformation behaviors of the PFA-reinforced rockfill materials under different confining pressures, consolidated stress ratios, cyclic stress ratios and PFA ratios. Testing results show that the residual deformation increased with increasing dynamic stress ratio or confining pressure in the PFA-reinforced material. Under the conditions of confining pressure of 300 kPa, the consolidation ratio of 1.5 and dynamic stress ratio of 0.4, the residual strain of PFA with a high content of 2% was 74% lower than that of rockfill at the same conditions. Thus, it is proved that the PFA can significantly reduce the residual deformation of the rockfill. The parameters in Sheng Zhujiang residual deformation model were also comparatively analyzed with the data of PFA-reinforced rockfill materials.

Key words: rockfill materials, polyurethane foam adhesive (PFA), dynamic triaxial tests, dynamic residual deformation behaviors, aseismic measure