Fuzzy-Based Method to Evaluate Soil Corrosivity for Prediction of Water Main Deterioration

Abstract

A fuzzy-based method is proposed to evaluate soil corrosivity from soil properties such as soil resistivity, pH, redox potential, sulfide content, and soil type. The fuzzy-based method considers three levels of soil corrosivity, noncorrosive, moderately corrosive, and corrosive. This is in contrast to the commonly used 10-point scoring (10-P) method that has only two classes, corrosive and noncorrosive. Membership functions for each of the soil properties are used to quantify their affinity to the level of soil corrosivity. These membership values form an evaluation matrix from which a weighted vector is developed using pair-wise soil property comparisons. The final classification is determined from the cross product of the weighted vector and the evaluation matrix. Two case studies are examined to validate the application of the proposed fuzzy-based method to predict soil corrosivity, and the results are compared to the 10-P method. Both case studies showed that the fuzzy-based method outperformed the 10-P method.