A Contribution to the Design of Tunnels Supported by a Pipe Roof

The increased use of pipe roof umbrella systems as a pre-support method necessitates the need for a standardized
approach to determine the basic design parameters during design. The knowledge gained by in situ measurements using in place inclinometer chains were used to identify key influencing factors and guide 3-D numerical investigations. These simulations acknowledged and advanced the geotechnical model based on the in situ measurement data. Due to this it is possible to calculate the estimated deformations and to determine the design parameters of a pipe roof umbrella system with numerical simulations. To control the estimated ground – support interaction and adapt the support to the actual rock mass quality the developed measurement system can be additionally used in sections that are very sensitive to subsidence. Using this knowledge an appropriate modeling scheme allows the determination of the required support. With a continuous adaptation of the support system to the encountered ground behavior during construction a safe end economical construction process is assured.