Remaining Life Determination and Risk Management Decision Support for Wastewater Pipes with External Inspections

Factors affecting the performance of infrastructure systems vary depending on the geographical, operation, maintenance, and socioeconomic factors. The key to an efficient infrastructure program is to understand these factors and identify proper inspection, condition assessment, and risk assessment strategies to provide effective decision support for infrastructure asset management. AECOM’s San Antonio Asset Management Team had been tasked to provide asset management services for a Department of Defense (DoD) installation in Northern Alaska. The assessed system is a closed loop system where the gravity and force main pipes are located inside the utility tunnels to protect utilities from harsh environmental conditions. The presence of the utility lines in the utilidors creates insufficient internal access to the wastewater pipes for inspections. The team conducted 96,000 linear feet of utility tunnel assessments and 49,000 linear feet of pipe inspections. This inspection data was used with the combination of other structural, environmental, and operational factors with the help of deterministic logical decision tree algorithms to assess the condition of utility tunnels and wastewater pipes. Statistical prediction models were then used to determine the remaining life of the assets inspected.