Evaluating Welded and Mechanical Pipe Joint Strength for Seismic Design: Part 1—Testing Protocol

The evaluation of welded steel pipe and pipe joint strength for resisting seismic forces is essential to establishing the design basis for today’s conveyance infrastructure. Unfortunately, little information is available for large diameter, thin wall, spiral welded steel pipe which is commonly used in the water and wastewater industry. As a result, pipeline designers will often use information tailored to other industries such as steel buildings and off-shore drilling structures which may not be relevant to welded steel water pipe and the use of this information could lead to unconservative results with questionable seismic resilience. The effects of internal pressure are known to augment the strength of welded steel pipe and joints however accurate test data suitable for design use is currently unavailable. This paper describes a planned testing program that will include physical tests to evaluate the strength of welded steel pipe, field welded joints, and mechanical joints under pressurized and non-pressurized conditions. The goal is to develop an understanding of how typical, large diameter steel pipe will perform when subjected to bending, tension, and compressive forces which are the basis of seismic resilience.