内張鋼管を用いたコンクリート円筒の応力解析について

抄録・要旨

For circular siphon barrels under high heads, it is advisable to use steel lining to ensure watertightness. This paper deals with the method for stress analysis of such steel-lined concrete cylinders under high internal pressure.
The principles for the analysis are based upon the assumption that the steel liner and the surrounding concrete would deform alike and work together in resisting internal pressure. Since the steel lining is relatively thin compared with diameter of the cylinder or thickness of the concrete shell, it is treated by using the approximate method as in the design of thin wall pressure pipes. The deformation of the outside concrete cylinder is determined by treating it as a thick-walled cylinder. The methods are extended to the case of a concrete cylinder with hoop reinforcement, considering the deformation of hoops of the reinforcing bar to be compatible with ajoining concrete.
The steel lining has a merit to assure watertightness of the pipe when cracks in concrete would occur. The method of stress analysis is therefore developed for the case in which the concrete portion is incapable of taking circumferential tension.
Numerical computations were carried out to illustrate the variations in stresses with dimensions of the cylinder section or quantities of reinforcement.