Design, Analysis, and Full-Scale Testing of the Rolled Groove Gasket Joint System in AWWA C303 Bar-Wrapped, Steel-Cylinder Concrete Pressure Pipe

摘要

This paper presents full-scale testing results of a 1,370-mm (54-in.) nominal diameter prototype rolled groove joint incorporated into a bar-wrapped concrete pressure pipe manufactured to American Water Works Association (AWWA) standard C303 specifications. The acceptance criteria for the prototype were no leakage or deformation at 1 MPa (150 psi) working pressure and 1.6 MPa (225 psi) transient pressure. The joint was also required to be watertight at 2 MPa (300 psi), which represented a factor of safety of 2 over working pressure. A 25.4-mm (1-in.) pull was used in the full-scale test to reflect the worst case scenario of an angularly deflected joint in the field to assess its ability to tolerate unsymmetrical fit. The test pipe was loaded in excess of its circumferential elastic limit, without any visible leakage at the joint. The three-dimensional (3D) nonlinear numerical simulation of the pipe joint was created by using software, resulting in acceptable comparisons with the experimental data. Data collection instrumentation included strain gauges, cable displacement transducers, and acoustic emissions (AE) technology. Joint design included an optimal stab depth for the spigot and appropriate rod-wrap termination design in both the bell and spigot to provide sufficient stiffness. The strain in the internal and external cement mortar layers remained below the ultimate strain of 0.2% up to 1.7 MPa (250 psi). A steel cylinder with complete-penetration helical butt welded seams, which will allow a groove to be roll-formed on the cylinder, with a minimum cylinder thickness of 3.4 mm (10 GA/0.135 in.), are noted as minimum requirements for the joint.