Evaluation of the effect of using fiber reinforcement in tunnel linings for metro projects

Abstract

Metro (subway) is an advanced public transport infrastructure system in urban areas with high capacity. The traffic operation of a metro is not affected by other vehicle traffic thanks to underground tunnels. With these benefits metro lines are preferred to solve the traffic problem in urbanized cities such as Istanbul, which is the focus of this study. Metro projects require huge amounts of budgets to be built. Putting these projects into service in targeted time is of great importance. The objective of this study is to minimize total metro construction project time by utilizing fiber reinforcement in tunnel linings. In this research, using fiber reinforcement to construct primary (initial) tunnel linings and secondary (final) tunnel linings of the metro projects are analyzed in terms of project duration. After comparison of two railway tunnel projects, evaluations and observations of a completed metro project revealed that using fiber reinforcement for either the primary lining or the final lining of tunnels reduces construction time of metro station tunnels by 25%. In addition, using fiber reinforcement to construct both the final lining and the primary lining of tunnels reduces construction time of the metro station tunnels and the whole metro project by 47% and 22%, respectively. The results of this study can be useful for completing challenging metro projects and putting it into service within the targeted time.