Evaluation of slope soundness using state space models based on expressway inspection data

Abstract

In this study, based on number of damaged places and their damage degree data which are obtained from slope inspection of expressway, two time-series models were developed using state space model to estimate soundness index of slopes for each expressway route. The soundness index of slopes was defined as three latent states: occurrence rate of the damaged places, the number of occurred damaged place, and the occurrence probabilities of damage degrees. The developed models were fitted using inspection data from three expressway routes in Akita Prefecture. The estimation of soundness index was performed using the Markov chain Monte Carlo method. Based on the estimation results, a discussion on the temporal variations of these latent states is presented.