Evaluation of Cross-Sectional Stiffness along Axial Direction in Cracked RC Pipes

Abstract

The authors have proposed the Internal Loading Method as a new strength evaluation method for buried pipes. This method is applied to RC pipes in previous studies and its effectiveness has been confirmed. However, these studies used test pipes with grooves to simulate cracks. In this research, damaged RC pipes are prepared by applying various loads with a compression-testing machine, and their stiffness is measured by the Internal Loading Method. In addition, the stiffness of RC pipes by different manufacturers was also examined. As a result, the Internal Loading Method was able to detect the trend of the relationship between the deformation and load on RC pipe. Furthermore, cross-sectional stiffness of joined pipes and a non-joined pipe was almost the same. The constraint of the connecting part on the pipe does not affect the stiffness with deformation of 70 micrometers. Finally, it was found that the relationship between the load and deformation differed by the manufactures of RC pipes.