Amirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X50220180522Reliability Analysis of Water Leakage Tunnels with Cracked and Uncracked Concrete Using Monte Carlo SimulationReliability Analysis of Water Leakage Tunnels with Cracked and Uncracked Concrete Using Monte Carlo Simulation409418104010.22060/ceej.2017.12415.5210FAA.FirouziDepartment of Construction Engineering and Management, Islamic Azad University, Science and Research Branch, Tehran, IranC.MohammadzadehDepartment of Construction Engineering and Management, Islamic Azad University, Science and Research Branch, Tehran, IranM.FeyziDepartment of Construction Engineering and Management, Islamic Azad University, Science and Research Branch, Tehran, IranJournal Article20170117<span class="fontstyle0">Water leakage from concrete tunnel structures is one of the phenomena which can affect their serviceability with certain problems. In this paper, the limit states of water leakage from cracked and uncracked concrete elements have been introduced whilst uncertainty of governing parameters is modelled as random variables. Using Monte Carlo simulation, failure probability and corresponding reliability index of tunnel sections with cracked concrete have been calculated in three modes, namely constant crack width, self-healing and expanding. The results of this analysis showed that concrete selfhealing does not have signifcant role in reduction of leakage probability. On the other hand, since crack width spreads during the service life of structure, an appropriate crack width increase model with time is necessary in order to determine the remaining life of tunnels. Moreover, for uncracked sections and sections that must be necessarily sealed, probability of leakage initiation has been computed during the service life of tunnel. For such structures, this reliability analysis can be utilized to determine the remaining life corresponding to the acceptable failure risk or in designing the minimum required<br />thickness of element and determining the properties of mix design and permeability of concrete.</span> <br /><br /><span class="fontstyle0">Water leakage from concrete tunnel structures is one of the phenomena which can affect their serviceability with certain problems. In this paper, the limit states of water leakage from cracked and uncracked concrete elements have been introduced whilst uncertainty of governing parameters is modelled as random variables. Using Monte Carlo simulation, failure probability and corresponding reliability index of tunnel sections with cracked concrete have been calculated in three modes, namely constant crack width, self-healing and expanding. The results of this analysis showed that concrete selfhealing does not have signifcant role in reduction of leakage probability. On the other hand, since crack width spreads during the service life of structure, an appropriate crack width increase model with time is necessary in order to determine the remaining life of tunnels. Moreover, for uncracked sections and sections that must be necessarily sealed, probability of leakage initiation has been computed during the service life of tunnel. For such structures, this reliability analysis can be utilized to determine the remaining life corresponding to the acceptable failure risk or in designing the minimum required<br />thickness of element and determining the properties of mix design and permeability of concrete.</span> <br /><br />https://ceej.aut.ac.ir/article_1040_fd9b1ceb563e011e2125ad8a9e1197b1.pdf