Langzeitstabilität von Ausbaumaterialien im Fels-Hohlraumbau

Translated title of the contribution: Long-Term Stability of Support Materials in Tunnel Constructions

Stefan Lorenz

Research output: ThesisDoctoral Thesis

Abstract

In current practice for common dimensioning of the tunnel linings may clients assume that the support elements of the outer lining looses its load bearing capacity and that the entire loadings of the rock are transferred to the inner lining. Observations and measurements on the inner linings of tunnels disagree with the theory and show that there are no loadings applied and therefor the dimensioning concept displays the reality insufficiently. The topic of the dissertation starts with this issue and draws conclusions from investigations of the support materials in tunneling onto the long term behavior. First, the target is to obtain a broad data basis of practical lifetime through examination of materials and components and in a second step to use this data as a foundation for a durability analysis of support materials. Therefore laboratory tests on support elements, which were used in present tunnels for 20-40 years, were made. The support materials were examined on aging with the current guidelines and compared with new material. For the evaluation of the stress state in the tunnel in-situ stress measurements on tunnel linings were made and the operating forces and the load sharing between tunnel linings determined. Therefore several experiments on sheet membranes in conjunction with the shotcrete and the inner lining were performed and the characteristic values for the contact area were defined. In order to confirm the in-situ measurements and to evaluate the load-bearing capacity numerical simulations have been made. With consideration of the obtained parameters the tunnel lining was modelled and calculated in an entire numerical model. The results of the investigations show, that the durability of the supporting elements in the analysed tunnels are guaranteed and that there is no appearing reduction of the stability. With these results some important conclusions can be postulated. The approach of the dimensioning for the loss of stability of the outer lining with simultaneous loss of the load bearing capacity of the examined tunnels can in most parts be refuted. Therefore this work builds the basis for further examination in the field of tunnel constructions.
Translated title of the contributionLong-Term Stability of Support Materials in Tunnel Constructions
Original languageGerman
QualificationDr.mont.
Supervisors/Advisors
  • Galler, Robert, Assessor A (internal)
  • Heck, Detlef, Assessor B (external), External person
Publication statusPublished - 2016

Bibliographical note

embargoed until null

Keywords

  • tunnel
  • long-term
  • support
  • durability

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