The design of precast tunnel segment under service load condition is mostly based on the axial force and bending moment (P-M) interaction diagram. This diagram is usually derived using flexural or tensile parameters obtained from short-term testing procedure. Considering the fact that the tunnel segments are subjected to prolonged loading, the effect of the long-term loading rate on these structures needs to be incorporated. In this paper, the assumption and model used for deriving the P-M diagram is discussed and then the procedure to include the rate-dependent tensile constitutive model in the design is presented. The rate-dependence of the P-M interaction diagram of the tunnel segment with conventional reinforcement and different type and dosage of fibres is discussed. © 2021, RILEM.