In this study, a 3D quasi-dynamic model is developed to simulate the rupture and healing processes of a buried fault plane. Furthermore, the Green's function of ground displacement due to a double couple point source can be derived for a 3D half-space. Considering the finiteness of the rupture plane, the total ground displacement at a specified ground observation point can be obtained by the integration of the Green's function over the fault plane. Then, the directivity effect and radiation pattern of near-fault ground motions can be determined. Based on the simulated typical pulse-like near-fault ground motions, the induced earthquake performance and the required ductility demand of structures can be evaluated.