Stresses in Rigid Pipe

In 1930 Marston theorized that earth pressures on a rigid pipe would assume bulb-shaped patterns. The theory was confirmed in experiments carried out at Iowa Engineering Experiment Station. In 1938 the theory was used to design the Salt Lake Aqueduct by Bureau of Reclamation personnel utilizing the latest work method. Subsequently, in 1950 the Bureau of Reclamation published Engineering Nonmograph No. 6 written by Olander and Entitled Stress Analysis of Concrete Pipe. This nomograph has led to a rather wide acceptance of the bulb-shaped bedding that is frequently referred to as Olander's Bedding. Unfortunately, this development, based on integral calculus methods, was somewhat limited in that only45°, 90°, 120° and 180° bedding were analyzed and because the point of maximum moment at the side was approximated.