Evaluation and Monitoring of Geotechnical Hazards Using UAV Based Digital Photogrammetry

Unmanned aerial vehicles (UAV), also known as drones, have become a very reliable and convenient tool to many engineering applications. Pipeline corridors are often exposed to geotechnical risk that may interrupt proper service. The risk sources vary, and range from steep hills to many site conditions such as ancient landslides, changes on phreatic water level, creeping soils, or geomorphological changes on the environment. Knowing and understanding the level of risk is highly dependent on identifying any geotechnical hazard in due time, before it materializes. Pipeline corridors are measured in kilometers, and the area that may adversely affect the corridor can vary from a few meters to several hundred on each side of the corridor. This paper presents an application of UAV based digital photogrammetry to evaluate and monitor the hazard and evolution of the site PK 469 OCENSA km 149 ODC. The site is maintained by Oleoducto Central S.A. (OCENSA), and the paper describes the different geotechnical studies and works carried out to maintain uninterrupted service of the pipeline. The paper includes technical information supporting the processing and characteristics of the photogrammetry based evaluation and monitoring method, to highlight the efficiency and accuracy of the proposed method.