The Benefits of Uncertainty and Risk Assessment Studies on the M5 Metro Line (Istanbul - Turkey)

Abstract

Uncertainty is often the most significant source of risk associated with a project in tunnel and underground construction. Unforeseen uncertainties can lead to significant construction problems leading to reduced tunnel advances and delays, cost increases, damage to existing infrastructure and/or damage to building equipment. The M5 metro line, which is the subject of the study, is located in Uskudar – Umraniye - Cekmekoy - Sancaktepe district on the Asian side of Istanbul. The line is approximately 17.5 km long and has 16 cut and cover stations. M5 metro line was used the four earth pressure balance (EPB) tunnel boring machines. The effect of uncertainty on risk assessment and decision-making is increasingly given priority, particularly for large infrastructure projects such as tunnels where uncertainty is often the primary source of risk. This article is intended to explain the tangible benefits of underground uncertainty and risk assessment of the M5 metro construction for underground project stakeholders, local authorities, designers, practitioners and researchers.