Experimental verification of tunnel linings effect

Project title: Experimental verification of tunnel linings effect (I and II)
Submitter: Czech Science Foundation (GAČR)
Project number: 103/05/2231 (I); č. 103/08/1691 (II)
Project leader: Czech Concrete Society ČSSI ( I); Professional society for science, research and consultancy ČSSI (II)
Main researcher: Prof. Ing. Jan L. Vítek, CSc. (ČVUT, METROSTAV, a. s.)
Researcher: Ing. Pavel Šourek (SATRA, spol. s r. o.)
Co-Researcher: Ing. František Polák, (SATRA, spol. s r. o.)
Period: 01.2005-12.2007 (I); 01.2008-12.2010 (etapa II)

Annotation

The number of tunnels under construction and tunnels which will be constructed in the furure keeps on increasing. Their importance is essential for road and railway transport and it is impossible to allow unnecessary traffi c closures or other traffic restrictions.

Designing of the final tunnels lining is a comparatively complicated process. The static effect depends on the tunnel lining interaction with the rock massif and the loading depends on many factors: the lining rigidity, stope size, geotechnical conditions, construction progress and last but not least, on climatic conditions. The structure evaluated is often statically indefi nite and it is impossible to apply directly the designing methods according to the limit values in a form that is standard in case of surface structures. Therefore, the lining design must be safe, economical and simultaneously, it must fulfill the highest requirements on utility characteristics for the entire lifetime of the Work. Experience with longterm functions and real stress vary all over the world and it is essential to verify the relevant experience in Czech conditions.

The research is supported by GACR also performed a number of measurements at both the implementation and the operation for which document the actual stresses, respectively, the real burden of tunnel lining. As part of this grant is all about measurement of strain (relative deformation) tunnel lining using a pre-loaded vibrating a weed strain gauges.

Using strain gauges are monitored so today in the Czech Republic such as these tunnels:

  • Valík tunnel, Highway D5 (Plzeň region)
  • Panenská tunnel, Highway D8 (Ústí region)
  • Libouchec tunnel, Highway D8 (Ústí region)
  • Klimkovice tunnel, Highway D1 (Moravian-Silesian region)
  • Mrázovka tunnel, Urban Ring (Prague)
  • Blanka tunnel complex, Urban Ring (Prague)
  • Vítkov railway tunnels, New Connection (Prague)
  • Cable tunnel Vltava (Prague)

The measured values ​​are compared with the results of numerical calculations for verifying the accuracy of static calculation assumptions and approaches of the designer, which can be highly subjective. The result of the project will be: a) Assessment of the extant measurement tunnels built in the Czech Republic, b) Verification of the assumptions of static analysis and action reveal the construction and operation of tunnels.