The ever-growing construction sector is considered as one of the main propellers of economy, especially in developing countries. Tunnels are one of the vastly developed infrastructures in which public and private sectors build and invest for various purposes, e.g. transport, water supply, and so on. In this regard, approaches to increase feasibility and performance of tunnels are developed to meet specific requirements. Introduction and usage of fibrous materials to strengthen mortar matrix, i.e. primarily decrease crack development and propagation, dates back to centuries ago [1]. In modern construction practice, fibers of different materials (steel, carbon, glass, polypropylene, …) are used to increase the post-crack tensile strength and flexural properties of the concrete mortar [1-3], known as Fiber Reinforced Concrete (FRC). The design framework for fiber reinforced concrete structural elements are standardized and introduced in recent design codes and regulations [4][5][6].