Proposal of Internal Loading Method to Evaluate Remaining Strength of Buried Pipe

— Evaluation of its applicability to RC pipes —

Abstract

The authors have proposed the Internal Loading Method as a new strength evaluation method for buried pipes. Previous studies have demonstrated the applicability of the Internal Loading Method to flexible PVC pipes. This paper reports on the result of applying this method for non-flexible RC pipes. Experiments were performed with RC pipes with a kerf on them. As a result, the Internal Loading Method can detect a kerf on the inner surface and on the outer surface as well. It was also possible to evaluate the depth. The possibility of damage by the application of this method is examined considering the load-deformation relationship and the amount of deformation residuals. The results showed that little damage is liable to occur as far as the load and deformation are controlled properly. Finally, this method was concluded to be applicable to both of PVC and RC pipes, because it can measure ring stiffness of pipes in wide range.