The importance of study on constitutive model of statically loaded rock experiencing dynamic load is set forth, and the studying methods on dynamic constitutive model are classified according to the current studying status. By way of combining statistic damage model and viscoelastic model, uni-axial and multi-axial constitutive models of statically loaded rock experiencing dynamic load (static-dynamic coupling constitutive model) under intermediate strain rate are established. The verification experiment on 2D constitutive model under different static stress and dynamic stress with different frequencies is designed and performed. It is found that there is a good agreement between the experimental stress-strain curves and the theoretical stress-strain curves.
Based on mesoscopic damage mechanics, numerical code RFPA2D (dynamic edition) was developed to analyze the influence of tunnel reinforcing on failure process of surrounding rock under explosive stress waves. The results show that the propagation phenomenon of stress wave in the surrounding rock of tunnel and the failure process of surrounding rock under explosive stress waves are reproduced realistically by using numerical code RFPA2D; from the failure process of surrounding rock, the place at which surrounding rock fractures is transferred because of tunnel reinforcing, and the rockfall and collapse caused by failure of surrounding rock are restrained by tunnel reinforcing; furthermore, the absolute values of peak values of major principal stress, and the minimal principal stress and shear stress at center point of tunnel roof are reduced because of tunnel reinforcing, and the displacement at center point of tunnel roof is reduced as well, consequently the stability of tunnel increases.
