The two dimensional transient response of a tunnel subjected to an uniform loadis described in this paper. The concrete tunnel is embedded in a limestone massif with a het-erogeneous chalk layer. The theoretical approach presented here is based on a semi-analyticalapproach in which the Helmholtz decomposition is used for the separation of wave motion andthe solutions of wave equations are written using the Bessel-Fourier serie expansion method inthe Laplace domain. The inversion of the Laplace transforms are performed numerically by us-ing the Durbin algorithm. An imperfect contact is used to take into account the discontinuitiesat the interfaces between the different media. The results of hoop stress and radial displacementon the outer boundary of the tunnel are presented.