Experimental and numerical study on the load-bearing behaviour of steel-fibre-reinforced concrete for precast tunnel lining segments under concentrated loads

摘要

To investigate the behaviour of precast tunnel lining segments subjected to concentrated loads on a small scale, laboratory tests on concrete prisms under partial-area loading in conjunction with numerical analyses were performed. Various parameters influencing the load-bearing and fracture behaviour of plain concrete (PC) and steel-fibre-reinforced concrete (SFRC) under concentrated loads are considered, including fibre properties (dimension, aspect ratio, tensile strength), fibre dosage and orientation, area ratio and eccentricity of load. The effects of these parameters on the ultimate bearing capacity, stress-displacement behaviour, failure mode and crack characteristics are analysed and discussed. Parallel to the experimental investigations, numerical simulations using a continuum coupled damage-plasticity model for triaxially loaded cementitious material were performed. It is shown that the numerical analysis is able to realistically capture the structural behaviour and the crack pattern of partially loaded PC and SFRC specimens.