Middle wall is an important structure of a double-arch tunnel. To prevent harmful influence by unsymmetrical pressure on middle-wall has become the key problem during double-arch tunnel construction because of its complicated stress and deformation rule. Based on the construction of eccentrically compressed entrance of Fuxi highway double-arch tunnel with heavily jointed soft rock mass

the deformation and internal stress distribution behaviors of the middle wall is analyzed by the three-dimensional numerical simulation in the course of construction. It can be concluded from the result that the top of middle wall moved towards shallow side effected by partial load induced by terrain

and the middle wall also moved backwards and forwards with excavation of left and right tunnel differently. If the top clearance of middle wall is not filled immediately

the displacement and internal stress state of middle wall can be improved effectively. According to the conclusions above some suggestions are made for construction of Fuxi tunnel.