2021 Volume 77 Issue 1 Pages 115-134
As deteriorated sewerage pipes are increasing, the efficient renewal of pipes is considered important. Since sewerage pipes are buried and form a complex underground network, it is effective to integrate a certain number of renewal projects and conduct them all at once. Accordingly, in this study, the authors estimate a mixed Markov deterioration hazard model by using the visual inspection data on concrete pipes, and evaluate the deterioration heterogeneity of individual pipes. Furthermore, the authors evaluate the spatial heterogeneity distribution obtained from heterogeneity parameters and the data on pipe locations with the dual Kernel density estimation, carry out the screening of intensive management districts, and propose a methodology for examining policies for renewing pipes. Lastly, the effectiveness of the proposed method is empirically discussed with reference to the cases of application to sewerage pipes managed by Osaka City.
