Seismic Performance of PVC-U Pipe and Design Prediction Tool

Investigations made following the 2010-2011 Canterbury Earthquake Sequence (CES) show that the underground pipes have signature failure modes that were unique to the pipe material and some types of pipes, such as those made of PVC, underwent multiple failure modes. Moreover, the damage to pipe joints appeared to show that adding axial joint load to the tests already mandated by NZ standards would greatly enhance the seismic design of pipes. For this purpose, an experimental investigation is conducted on PVC-U pipe joints to ascertain the serviceability and ultimate limit state allowable loads when a pipe joint is subjected to axial seismic-simulated actions. The results are able to replicate the observed earthquake damage by incorporating forces simulating peak ground accelerations in both the horizontal and vertical directions in the testing. From the results, a theoretical framework is developed to illustrate how seismically induced axial forces can be generated in the pipe joint.