P.E. Abstract Beginning in 1943 more than 28,000 miles of large diameter prestressed concrete pipelines have been placed in service, principally as water transmission mains, operating at pressures as high as 250 psi. Although the pipes have generally performed well, over 500 failures due to exterior corrosion have occurred since 1955.
Ruptures are often catastrophic causing considerable damage as well as loss of service.
Almost all of these pipelines are buried under varied depths and conditions making internal inspection the most practical method for detection of distress and prevention of bursts. These indications of incipient failure are discernible by internal inspection. Delaminations are detected by continuous sounding of the lining with a length of small diameter steel pipe. Characteristically the signature cracks appear longitudinally disposed on the side quadrants of the lining and are outlined with surface deposits of carbonate. To develop a procedure for locating distressed pipe sections before they burst, it is necessary to hypothesize the sequence of events which will likely take place before rupture.