UNDERGROUND EXCAVATION DESIGN AND CONSTRUCTION OF SUBWAY TUNNELS THROUGH RAILWAY BOX CULVERTS

Underground excavation of the subway tunnels through is the normal operation of five railway box culverts. According to the control standard of railway deformation in safe operation, a special design was made for the tunnels excavation under railway box culverts. The big pipes shed+pre-grouting small tubes were used in advance support. The initial support of the tunnel was made of steel grille+shotcrete, and the temporary inverted arch was set. In order to facilitate the construction and operation of the big pipe shed, the operation room support of the pipe shed was designed. According to the positioning and guiding design of the large pipe shed, the positioning and guiding scheme were compared and reinforced concrete guide wall was adopted. The construction technology and grouting parameters of large pipe shed and pre-grouting small tubes were designed. The steel grille+shotcrete and the temporary reverse arch were used to support surrounding rocks in tunnels. The emergency plan was designed for the construction. At present, the project was safely completed, this paper will provide reference for those subway tunnels excavation under railway box culverts.