JACKING OF A FOUR-LANE ROAD TUNNEL CONSISTING OF A REINFORCED CONCRETE BOX SECTION UNDER THE MAIN LINE OF THE GERMAN FEDERAL RAILWAYS AS PART OF THE "WEST TANGENT" OF THE BOCHUM MOTORWAY. SECOND INTERNATIONAL TUNNELLING SYMPOSIUM, MUNICH, 12 APRIL 1989

This article describes the construction of the reinforced concrete box section of a 4 lane road tunnel under a main railway line using a pipe jacking method. This method enabled the tunnelling to be carried out without impeding rail traffic, even through cover was only about 4 m in depth. (loosely laid embankment, clay or loose and solid rock.) the tunnel structure was built on sliding tracks next to the railway embankment. Extensions of these tracks were laid manually in the railway embankment during construction. The roof and sides of the tunnel were surrounded with plates which could be driven forward from the rear by 4 compression mountings. The height of the face front was divided by an intermediate scaffold, which was supported by partitions in the middle of each tube so that the face in front of each tube was divided into 4 separate sections. During construction the structure was moved on 3 ground tables which not only supported the weight of the overhead traffic and of the tunnel itself, but also transmitted the feed forces. The feed forces were diverted under the structure by shearing forces between the ground tables and the ground itself. The German title of this paper is as follows: durchpressung einer bundesbahnhauptstrecke im bochum mit einem vierspurigen strassentunnel im zuge der westtangente. For the covering abstract of the conference see IRRD 824157.