Evaluation of Interlocking Joint Mechanism Used in Auger Boring Pipe Casings

摘要

Pipe interlocking joints are commonly used in auger boring operations as they have proven to be cost effective by reducing installation time and labor (Toloui et.al., 2009 and Wallin and Bennett, 2016). Although, the trenchless technology industry is very familiar with such joints, relatively little is understood about the joining process from a mechanical standpoint.This paper provides key experimental results of the engagement and disengagement forces during auger boring installation of steel pipe casings and discusses how the geometry of the male and female ends of an interlocking joint interact during joining. Experimental tests were conducted on four sets of 36-inch diameter steel pipes with 7-inch long notched male and female bands welded to the ends. Each band had four notches machined into the bands over a 3-inch length. All four sets were tested to determine the engage and disengage forces.Finite Element Analysis (FEA) was implemented to study and understand the mechanics of the joint while engaging and disengaging. Insights gained from the FEA of the joint are presented, including a contour plot of stress on a deflected joint during engagement. Ongoing research work that could lead to an optimized pipe joint for auger boring casings is highlighted.