The use of fiber reinforced concrete (FRC) in tunnel linings, with or without conventional rebars, has increased in the two last decades, especially in segmental linings. Nowadays there is a growing interest in the scientific community on macro-synthetic fibers for use in underground structures. Within this framework, the present study investigates the possibility of using macro-synthetic fiber reinforcement in precast tunnel segments in a possible combination with conventional rebars. An experimental program based on 3 Point Bending Tests was carried out on FRCs characterized by different fiber contents in order to assess their post-cracking nominal residual stresses. The corresponding stress vs. crack opening laws, representative of the FRCs investigated, were calculated through inverse analysis procedure. Then, a typical tunnel lining having small diameter was adopted as reference to optimize the reinforcement solution (macro-synthetic fibers and conventional rebars, i.e. hybrid solution). Particular attention was devoted to the TBM thrust phase, in which high-concentrated forces are introduced in the linings.

Optimized reinforcement for precast tunnel segments with macro-synthetic fibers

Giuseppe Tiberti;Giovanni Plizzari;Antonio Conforti;TRABUCCHI, IVAN
2018-01-01

Abstract

The use of fiber reinforced concrete (FRC) in tunnel linings, with or without conventional rebars, has increased in the two last decades, especially in segmental linings. Nowadays there is a growing interest in the scientific community on macro-synthetic fibers for use in underground structures. Within this framework, the present study investigates the possibility of using macro-synthetic fiber reinforcement in precast tunnel segments in a possible combination with conventional rebars. An experimental program based on 3 Point Bending Tests was carried out on FRCs characterized by different fiber contents in order to assess their post-cracking nominal residual stresses. The corresponding stress vs. crack opening laws, representative of the FRCs investigated, were calculated through inverse analysis procedure. Then, a typical tunnel lining having small diameter was adopted as reference to optimize the reinforcement solution (macro-synthetic fibers and conventional rebars, i.e. hybrid solution). Particular attention was devoted to the TBM thrust phase, in which high-concentrated forces are introduced in the linings.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11379/507563
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact