Abstract

This paper describes an experimental and analytical research consisting of a real scale in situ test of SFRC (Steel Fiber Reinforced Concrete) segmental lining of the subway Line 9 (L9) in Barcelona. The research was aimed at providing experimental evidence of the real behavior of SFRC segmental tunnel linings. The project of L9 is a 12 m diameter TBM-excavated tunnel of about 40 km length. For research purposes, an experimental section of 15 rings was built using concrete with 60 kg/m3 of steel fibers as unique reinforcement. It was decided to carry out an in situ loading test on one ring of that experimental section. Two hydraulic flat jacks embedded at the extrados of the ring and located close to the tunnel crown were used to apply the loads (max 3000 kN). A complete set of internal and external instruments were placed in the tested rings. Material properties of the SFRC were controlled during construction using compression tests, 4 point beam tests and double punch tests (Barcelona test). Results from the experiment and its numerical simulation (2D and 3D) are presented and discussed.