Tunnel surveying. Routing, geometry and surveying for the airport underpass of the Stuttgart S-Bahn

Construction of the airport underpass will extend the greater Stuttgart area S-Bahn southwards as far as Filderstadt-Bernhausen. The line is designed for a speed of 80 km/hr. Routing had to take account of geometrical and geological parameters. A uniform tunnel profile, optimized by geometric investigations, was chosen for the single track line. Prior to the construction work, the above-ground base grid was determined using a satellite-assisted method. The underground tunnel driving grid had to be backed up with gyroscopic measurements. Tunneling under the runway entailed a comprehensive program of surface and deformation measurements in the tunnel. Motor lasers were used for the tunnel excavation control and the minimum excavation line was verified using tunnel scanners. The extension of the S-Bahn from the Stuttgart airport to Bernhausen supplements the Integrated Local Transport System for the Greater Stuttgart Region using an about 2.8 km long southern section. The new S-Bahn station of Filderstadt-Bernhausen is built centrally in the city of Filderstadt. The attractive S-Bahn connection can be reached by many inhabitants on foot or by bus. The startup of this S-Bahn stretch is due in the fall of 2001. The discussion covers the selection of route; satellite supported triangulation for construction of the work; geometry of the tunnel cross section and optimization of the tunnel construction coordinate; surface measurement program; analysis calculations of the to be expected tunnel breakthrough error; directional transmissions for tunnel propulsion (instrumentation, underground polygon system, gyro stabilization, and breakthrough error); propulsion control (motor laser, profile control, and construction survey of the inside shell); geotechnical measurements in the tunnel; and responsibilities between the customer and the contractor. Maps, photographs, diagrams, and graphs.