(47f) Phenomenological Study of Hazardous Gas Releases from Buried Pipelines

Sudden leaks from underground pipelines can occur mainly due to corrosion and third-party damages, causing the emission of hazardous materials that can potentially escalate and lead to disastrous incidents. Understanding the phenomena accompanying the gas releases is key to mitigating the associated risks. This work aims at identifying the main gap in the literature of underground gas releases and proposing a model and an experimental setup to cover this gap. Three main underground flow regimes are identified: migration of gas though the ground (with diffusion and advection as the main phenomena), ground uplift (with fluidization of the underground bed), and crater formation (with a free jet throughout the ground). The review of the state-of-the-art indicated the lack of a study that covers the entire spectrum of these regimes consecutively. In this work, we propose a mechanistic approach using the transient average soil volume fraction distribution to identify the regime in a computational model. The model indicates that a higher pipeline pressure and lower burial depth promote the formation of a crater. A laboratory scale experimental setup is proposed to visualize and quantify the transient soil behavior across the bed throughout the leak at different regimes.