Random Proportional Weibull Hazard Model for Predicting Deterioration of Educational Facilities

In asset management of infrastructures, predicting deterioration of structures is one of an essential technique. Especially this study focuses on educational facilities from among social infrastructures. However, as for such kind of the facilities that consist of a large number of structural components, in order to estimate their deterioration process with high accuracy, the heterogeneity of individual components has to be considered because each component possesses different material characteristics and designs and is in unique service under various environmental conditions. This paper addresses the random proportional Weibull hazard model that is possible to consider the heterogeneity of individual components as probability fluctuation in the hazard rate. Specifically, the time-dependent hazard rate is formulated by the Weibull hazard model. The heterogeneity of the hazard rates across the individual characteristics of components is explained by the random proportional Weibull hazard model in which the hazard rates are subject to Gamma distribution. This study also presents the estimation techniques for the proposed model based on the maximum likelihood estimation method. In addition, through an empirical study employing visual inspection data for an actual university facility, with deterioration prediction for components, the validity of the method is verified.