Using Controlled Global Buckling to Improve Buried Pipelines Performance Under Large Compressive Ground Displacements

Abstract

This paper presents the basic concept and verification tests results of a novel method designed to prevent failures of buried pipelines subjected to compressive deformations which are usually caused by ground movements. In this method the boundary conditions of the buried pipes are modified by installing soft elements next to the pipe before backfilling. With the new boundary conditions, the pipe response under large compressive forces will be in form of a stable global buckling mode with a predefined deformed shape. This behavior prevents rapid increase in the compressive axial force that causes local buckling, wrinkling, and subsequent softening, and strain localization. By using this method, pipes can have an extended compressive hardening response that absorbs large compressive displacements. The evaluation of this concept and its performance level were studied through a series of lab tests on 4-1/2 inch pipe specimens under simulated field conditions. The test results confirmed the anticipated performance of this technique which can evolve into a design method.