Experimental and Numerical Study Regarding the Behavior of HDPE Pipes under Quasi-Static Point Loads

Abstract

High-density polyethylene (HDPE) buried pipes are flexible structures, subjected to particular loading conditions. In different statistical data such as the United Kingdom Onshore Pipeline Operators’ Association (UKOPA) and European Gas Pipeline Incident Data Group (EGIG) databases it was observed that the main cause of their failure is the excavation damage. Therefore, it is important to determine the connection between the maximum force and the bearing capacity of the pipes during practical working conditions to avoid the pipe damage risk under external loads such as third-party intervention by means of excavating equipment. This paper analyzes the mechanical behavior of HDPE pipes under the excavation loads that may accidentally occur. For this purpose, numerical and experimental investigations were performed, considering the influence of different factors, such as the pipe diameter, pipe wall thickness, internal pressure, and the dimensions of the active element of the heavy excavation equipment. In the present study, a good correlation between the experimental tests and the numerical analysis was obtained (3.70% for the loads applied and 7.25% for displacement), both for the maximum force that can be applied and the corresponding deformation in the pipe wall. This study can be used to identify if the operation of a certain type of excavator near a HDPE pipe is safe, taking into account the puncture loads in quasi-static conditions.