Abstract:Based on Biot’s theory of two-phase medium, a high-precision indirect boundary integral equation method is utilized to solve the transient dynamic response of elastic tunnel embedded in a saturated poroelastic half space under internal blast loading. Response time history about the ground displacement, tunnel hoop stress, radial displacement and pore pressure of surrounding rock under blast load are given by calculating, and analyzed the difference of time history response between the saturated half space and the whole space. The results show that the embedded depth has large effect on dynamic response of the shallow buried tunnel-surrounding rock system; the boundary drainage condition has little impact on the time history response under blast load. With the increase of porosity, the influence of blast load on surrounding saturated rock is reduced while the blast effects on the tunnel is increased. When the direct waves and reflected waves by tunnel surfaces are strengthened by the reflected waves from the half-space surface, the tunnel vault is obviously affected by the surface reflection wave and the amplitude of hoop stress and radial displacement of surrounding rock are much larger than the tunnel in a whole space.