Tensile crack induced by differential settlement is the primary cause and typical form in earth-rock dam failure. The classical deformation gradient method is extended by coupling with finite element method. The newly developed deformation gradient finite element method is used to calculate deformation gradient with deformation obtained by conventional FEM instead of on-site monitoring data. This method is simple

and can be used to estimate the risk of tensile cracking in the design phase of dam construction. The possibility of tensile cracking caused by post deformation in Nuozhadu high earth core rockfill dam is analyzed with the method proposed. The distribution rules of deformation gradient and its relation with post deformation are discussed. The analytical results show that: in Nuozhadu high earth core rockfill dam

the post settlement at dam crest is smaller than 0.39 percent of the dam height; so that tensile cracking is almost impossible. According to the case study

the proposed method is applicable to cracking analysis of high earth-rock dam.