Towards Solid Ground: Integrated Components of Landslide Threat Management

Abstract As conduits of energy, pipelines convey products from a point of origin to end-users. On the way, each pipeline inevitably traverses natural geographical landforms, including slopes and waterways, which can impart stresses to the pipe. Over time, weather-related and outside forces alter the landscape and pipelines may be subject to interacting effects of ground movement, in terms of imparted high axial/longitudinal stresses that may not have been accounted for in the pipeline design. Evaluation of these effects can identify when the operating safety margin of the pipe is threatened and if intervention is required to maintain structural integrity. Different than the steady progression of time dependent corrosion and axial cracking, ground movement is episodic with a trend towards accelerating rates leading to slope failure. Successful management of ground movement therefore requires sufficient lead time to observe early effects and plan intervention. We present herein the integration of three components that form a basis for holistic landslide threat management: a structured tool that estimates probability of failure (POF) for landslides combined with a parameterized tool that evaluates pipe resilience underground movement, and a visual analytics tool for ILI/IMU bending strains, that independently validates the findings of POF and pipe resilience. The POF Calculator for Landslides is a structured tool to calculate probability of failure (POF) using expert judgment supported by known, instrumented or observable conditions and statistics (where available). This tool is augmented with discretized Pipe Vulnerability relative to magnitude of displacement for more accurate characterization of effects due to ground movement, thereby providing a high-level screening for strain-based design and assessment (SBDA) in advance of full evaluation using FEA. We show how analysis of measured bending strains can be used to corroborate findings from the POF Calculator for Landslides, providing assurance that the model is valid. The integration of these components is designed to provide a reliable basis for informing decisions and establishing plans to manage the threat of landslides interacting with pipelines.