ABSTRACT

Shotcrete is widely used as rock support and can support the load from blocks either by bonding to the rock or by bending between rock bolts. By introducing fibres, the ductility of the shotcrete will increase and the crack widths decrease. Predictions of the structural behaviour for fibre reinforced shotcrete (FRS) are however complicated due to the large scatter normally seen in test results. The reason is mainly related to the non-uniform distribution and orientation of the fibres which could lead to uncertainties regarding the quality of in-situ shotcrete. The aim with this paper is therefore to investigate if a probabilistic material model for FRS can be used to capture the scatter in the results. An isotropic damage model that combines an exponential softening curve for unreinforced shotcrete and a bi-linear curve to account for the effect of fibres were used. Suitable distributions for each of the parameters in the model have been proposed based on fitting of experimental results. Thereafter, Monte Carlo simulations were used to produce results for a large number of lab tests. Results show that the model together with the proposed distributions was able to capture the scatter in test results.