Upheaval buckling of buried pipelines

Abstract

This thesis is divided into two parts. The first part consists of an introduction to theory and design aspects regarding the subject of thermal buckling with main focus on buried pipelines. The second part introduces the reader to the experiments performed in this thesis, including the analytical tests performed in ANSYS followed by a presentation of the derived results. Analysis of the results, conclusions and recommendations for further work is presented in the final chapter. A lifting experiment was performed to detect and analyze the resistance provided by different soils. Upheaval buckling experiments were performed to detect a general behavior of a pipe in different upheaval buckling scenarios. Several scenarios regarding upheaval buckling were tested including; - Upheaval buckling over an imperfection with gravel, sand and clay as cover respectively - Upheaval buckling with a trenched pipe without cover in granular soils - Creep scenario simulating a pipeline going in and out of service while buried in clay - Upheaval buckling with various imperfection heights while buried in clay Most of the experiments provided interesting results, and some unforeseen happenings with the experiments in clay led to tough challenges. This also made some of the intended objectives for the thesis hard to fulfill. All performed experiments are presented graphically in the appendix. A CD with videos from the experiments, analytical calculation summaries and measured data is attached to this thesis available for external overview and verification. It is recommended that you watch the video before reading.