The hydraulic fracture of the gravity dam was analysed by considering the advantages of the numerical manifold method in the non-continuum field and the basic principle of fracture mechanics. Besides

this study realised the whole process of dam crack initiation

propagation and progressive failure. With the respective advantages of the Mohr-Coulomb failure criterion with tensile strength and the stress intensity factor discriminant criterion

the fracture and its propagating direction were determined according to different conditions

and no pre-notched model was required. One example under two different conditions was selected to analyse the hydraulic fracture of the gravity dam with or without considering the inner water pressure on crack. The results showed that for the hydraulic fracture of gravity dam without considering inner water pressure on crack

the crack of dam site propagated toward the direction of downstream and depth

and the crack propagation at the upstream slope belonged to the compression-shear failure. However

when considering the inner water pressure on crack

the crack of the dam site was extended in the direction of depth

and the crack propagation of slope point belonged to the tension-shear failure. Furthermore

the required time steps for the dam failure were reduced

resulting in the decrease of the safety factor of the dam. This study has deepened the understanding of hydraulic fracture of the gravity dam and has great practical application value.