Performance assessment of deteriorated RC shield tunnels integrated with stochastic field-based modeling for nonuniform steel corrosion

Abstract

For a corrosion-affected reinforced concrete (RC) shield tunnel, the corrosion of steel reinforcements is always nonuniform and spatially distributed. Ignoring the nonuniformity of steel corrosion shall not accurately estimate the performance of the deteriorated RC shield tunnel due to a drastic simplification of structural corrosion condition. In this study, a novel approach is presented to estimate the structural performance of a deteriorated RC shield tunnel with an emphasize on the spatial correlation and variation of steel corrosion. A random field integrated with Gumbel model is established to simulate the nonuniform steel corrosion in a segment. A random field-based numerical model for the deteriorated RC segmental lining and an analytical model to evaluate the load-bearing capacity of a corroded RC segment are developed. Monte Carlo simulation incorporating with numerical analysis is performed to estimate the failure probability of a deteriorated RC shield tunnel. In an illustrative example, the effects of corrosion degree and nonuniformity of the internal and external steel reinforcements on structural performance of a RC shield tunnel are investigated.