Behaviour of bell and spigot joints in buried reinforced concrete pipelines

Abstract

Joint behaviour in reinforced concrete pipes when buried and subjected to service live loading needs to be assessed to define the expected response of these elements, as excessive rotation and (or) shear across the joint could generate structural damage or leakage and subsequent loss in soil support that can bring the system to its serviceability or resistance limits. Two reinforced concrete pipelines with bell and spigot joints, one 600 mm (24 in.) and the other 1200 mm (48 in.) in diameter, were buried and subjected to the maximum service live loading for a simulated wheel pair at three independent locations above the pipeline. The smaller specimen was also tested with the protruding bells placed directly on the stiff foundation. Each pipeline was then tested up to and beyond the fully factored load at shallow cover and with the load applied directly over the central joint. The response of a single joint within the pipe system can be conservatively evaluated considering two rigid pipes connected by a hinge, and considering a single wheel pair (not axle loads), the most severe surface load condition. Neglecting leakage that was not studied, the joint strength was controlled by the circumferential response of the bells.