Assessment and extension of the service life of transport structures based on reliability theory under the conditions of Uzbekistan

Abstract

This study presents a comprehensive reliability-based and probabilistic framework for evaluating the service life of transport structures operating under the extreme environmental and seismic conditions of the Republic of Uzbekistan [1, 2, 3]. The proposed methodology integrates time-dependent degradation modeling, reliability index analysis, Monte Carlo simulation, and life-cycle cost (LCC) optimization into a unified assessment approach. Environmental aggressiveness-including high temperature amplitudes, saline groundwater exposure, carbonation, chloride-induced corrosion, and seismic loading-is incorporated into the degradation model through regionally calibrated parameters. The reliability index and probability of failure (Pf) are evaluated as time-dependent functions, allowing for quantitative prediction of structural safety throughout the operational period. Uncertainty in resistance, load effects, and corrosion rate is addressed using probabilistic distributions and stochastic simulation techniques. Furthermore, economic optimization based on discounted life-cycle cost analysis is employed to determine optimal maintenance and strengthening strategies. The integrated framework provides a scientifically substantiated basis for preventive maintenance planning and service life extension, ensuring sustainable, cost-effective, and safe operation of transport infrastructure in Uzbekistan.