Title: Design of FRC tunnel segments considering the ductility requirements of the fib Model Code 2010: Application to the Barcelona Metro Line 9

Author(s): Albert de la Fuente; Liao Lin; Sergio Cavalaro; Antonio Aguado

Publication: Symposium Paper

Volume: 310

Issue:

Appears on pages(s): 471-480

Keywords: Cracking bending moment, design, ductility, FRC, precast segments.

DOI:

Date: 3/17/2017

Abstract:
In tunnels built by means of a tunnel boring machine, the use of fibre-reinforced concrete (FRC) in the precast segmental linings lead to several advantages. On one hand, FRC improves the mechanical behaviour of the segments during construction, reducing the incidence of damages. On the other hand, it contributes to a decrease of the global costs by reducing the amount of conventional passive reinforcement required. The objective of this paper is to present a real experience regarding the use of fibres as the main reinforcement in precast segmental linings in the metropolitan area of Barcelona. First, the design approach presented in the fib Model Code for Concrete Structures 2010 for fibre-reinforced concrete is adapted taking into account the mechanical requirements of the precast segments. Then, this methodology is used to assess the minimum fibre content for this application, estimated in 60 kg/m³. These results are compared with the obtained in an experimental program performed with real-scale segments simulating the critical load condition found during the most critical transient stage (stocking). The study shows an example of optimized design of FRC tunnel segments that might be useful for future tunnels.