Statistical selection of deterioration factors in RC slab of urban expressway

Precedents for statistical selection of deterioration factors in RC slabs of urban expressway have not been accumulated very much. In this study, the authors focus on the deterioration of RC slab in urban expressway and clarify its deterioration process using statistical methods. In this study, the detailed visual inspection data of RC slabs inspected each panel which compose a single RC slab are adopted. The authors employ the Markov deterioration hazard model as a concrete method to select deterioration factors and to estimate the expected lifespan of each panel. Regarding to deterioration factors, 15 kinds of characteristic variables are considered as candidates of the factors, and by comparison of t-value and AIC, the factors having the significant interpretability can be selected. In addition, by estimating the Markov deterioration hazard model, Markov transition probability can be estimated. Then, using the Markov transition probability and Monte Carlo simulation, the expected lifespan of each RC slab can be calculated. By using the result of this study, when we determine the number of panels per a RC slab, the number of construction joint panels and the characteristic variables, expected deterioration path of the RC slab can be obtained.