MECHANISTIC MODEL FOR TRANSITION-PROBABILITIES

One important input in a pavement-management system is the matrix of t ransition probabilities. A methodology is proposed that employs mechan istic distress submodels for evaluating pavement distresses in terms o f fundamental material behavior and structural response to environment and traffic factors. This approach allows the distress modes to be mo deled individually so that the appropriate measures for correcting def iciencies can be readily identified. The performance submodels are for mulated within a stochastic framework for determining the transition p robabilities. The formulation is based on state-of-the-art structural reliability methods, specifically, the first-order reliability method (FORM), and is applicable to individual and combined modes of distress es. It is able to handle numerous variables with various distribution types and correlations. The multimode distress case is an extension of the individual distress modes incorporating the concept of cut-sets a nd directional simulation. With the proposed methodology, the assumpti on of a time-invariance matrix of transition probabilities, as adopted in existing pavement-management systems, is no longer necessary.