Experimental response of a fusible PVC pipe with service connections to axial pullout

Abstract

This paper investigates the axial pullout response of a fusible polyvinyl chloride (FPVC) main pipe with two service connections. A large-scale pullout experiment in dense sand was conducted to investigate the behaviour of service lines to axial pullout of the main pipe and the impact of service connections on the main pipe’s axial pullout resistance, axial force distribution, and moment distribution. The study assesses the response of both crosslinked polyethylene (PEX) and copper service lines as well as the role of goosenecks. Distributed fibre optic sensors (DFOS) have provided insight into the strain distributions along the main pipe and service lines. The experimental results have shown that service connections significantly increase the axial pullout resistance of the main pipe when compared to a previous test on an identical pipe without service connections. The movement of the service connections was found to reduce the earth pressure in a region behind the service connection. Hinging of the service saddles was observed to result in single curvature bending of the service lines. DFOS data along the main pipe has been used to approximate the individual load-displacement responses of the PEX and copper service connections.