Translation from original language as provided by author (1) Augmented Lagrangian method is adopted to improve the original contact algorithm of penalty method in DDA method. Computation of examples indicates that, for this improvement, computation result of contact forces between blocks and deformation analysis of block systems may not vary with different penalty number choices anymore, and with a relative small penalty number, accurate contact force and deformation result can be obtained. (2) Dynamic response of DDA block systems is calculated to study the stress wave propagation characteristics of DDA block systems. Result indicates that, compared with that in continua, stress amplitudes in DDA block systems may attenuate much faster and its propagating speed is much smaller. Both joint density and joint strength may affect the propagation of stress waves. (3) In order to use DDA method to solute problems in infinite and semi-infinite mediums, two non-reflecting boundary conditions including viscous boundary and superpositional boundary are implemented in DDA method. (4) Sub-block DDA method to deal with crack problems is developed. The failure computation of samples under tensile and compressive loadings indicates that, sub-block DDA method can simulate the initiation, propagation and the coalescence of cracks relatively well, and the whole failure style of the samples is in good agreement with other corresponding numerical result or experimental result. (5) By tracking borehole expansion and the propagation and coalescence of cracks in surrounding medium, DDA method to simulate the blasting process in jointed rock mass only with the consideration of the effect of explosion product pressure is developed. Computation of horizontal column borehole cast blasting with different burdens indicates that, with the increase of the burden, the blasting pile state show that the blasting design is varying from cast blasting to loose