ABSTRACT
An improved method of analysis based on bi-axial compressive membrane action has been developed to assess the peak load and stiffness of flat unbonded Fibre Reinforced Shotcrete (FRS) linings. The predictions of this method are verified against full scale tests conducted on macro-synthetic FRS linings in an underground coal mine. The method of analysis is then used to perform a series of parametric analyses to determine the relative influence of lining thickness, bolt span, radial stiffness, compressive strength of the concrete, and residual tensile strength of the FRS, on peak load and stiffness. The results indicate that thickness and radial stiffness appear to dominate the load resistance of flat unbonded linings acting in bending, largely due to compressive dome action between the point of loading and the perimeter. Compressive strength of the concrete has a more pronounced influence on peak load resistance than the tensile strength of the FRS.
