Developments in design for fibre-reinforced concrete tunnel segments
Mehdi Bakhshi; Verya Nasri
Appears on pages(s):
Design, fibre, lining, segment, tunnel.
Precast fibre-reinforced concrete (FRC) segments are increasingly being adopted in tunnel boring machine (TBM) tunnels to take advantage of their potential for production cost saving, improved handling robustness and long-term durability benefits. This paper presents a procedure for the structural design of FRC segments. The procedure includes design of FRC
lining for production and transitional load cases of demolding, storage, transportation and handling. In addition, construction load cases of TBM thrust jack forces and grouting pressure
are discussed. Ground and groundwater loads and force transfer in joints in the final service stage are presented as critical load cases. The proposed design approach is applied to the case of mid-size tunnel. Results show that when the design forces are not relatively large in comparison with the segment cross-section dimension, the use of fibres can lead to
elimination or a significant reduction of the steel bars, which in turn results in significant construction cost saving.