Bend Strain Estimation Method to Verify the Structural Safety of Buried Pipeline

Abstract

Recently agricultural pipelines used longer than their durable years are increasing. Appropriate evaluations of the structural safety of buried pipeline are required for effective preservation of aging pipelines to prevent failures by the deterioration. However, it is difficult to quantitatively evaluate the structural safety with a conventional method that measures pipe deflection which denotes simple cross-sectional deformation. Thus a new verification method is required to quantitatively evaluate structural safety. Therefore, a new method that estimates the bending strains by measuring changes in the curvature of pipes was developed. Experiments with a welded steel pipe were conducted to estimate the accuracy of the method. Results of the experiments show that structural safety can quantitatively and easily be evaluated with this method and its accuracy is more than 80 percent with strains greater than 1,000μ bending strains.