Abstract: Smoothed particle hydrodynamics (SPH) is a new meshless method and is gradually developed to the field of landslide analysis due to its advantages in large deformation simulation. However, flow rule and dilatancy angle has an important influence on the motion characteristics of slope after failure, but the analysis of their influence on large deformation slope is rarely reported. In this paper, the procedure of SPH based on elastic-plastic constitutive and D-P yield criterions was implemented in Fortran. Then, through two typical examples, the influence of flow rules and dilatancy angle on landslide analysis were discussed by using associated flow rule and non-associated flow rule (? =0 and ? =1/2? respectively). The results show that: excessive expansion will be produced when using associate flow rule and non-associated flow rule with ? =1/2? , both cases above are not in conformity with the actual situation. However, the non-associated flow rule with ? =0 can obtain the satisfactory result when calculating non-expansive soil, but will cause smaller speed and sliding distance when simulating expansive soil. Non-associated flow rule with appropriate consideration of expansion (? =(0.1～0.2)?) is suggested when calculating post-failure behavior of expansive soil and could obtain satisfactory results.

Key words: smoothed particle hydrodynamics (SPH), large deformation of slope, flow rules, dilatancy angle