Better Data Equals Better Decisions: New Developments in Multi-Sensor Condition Assessment Technologies

Abstract

This paper describes the development and successful applications of a closed circuit television (CCTV), LIDAR and sonar based pipe inspection system that is robust to gather quantitative data for critical underground pipe condition assessment. The system that can be deployed on a ROV or on a float and produces accurate cross-sectional analysis and sediment volume. This capacity is increasingly critical in large diameter pipes with high level of flow. The system employs a time of flight LIDAR that is accurate to 1/16th of an inch. Results from recent projects are discussed in detail. The Huntington Trunk sewer in Abbotsford, British Columbia, Canada is a critical line in the municipality’s waste-water system. It is a PVC and high density polyethylene (HDPE) pipe that also carries sewage from Sumas, WA. Pipe diameters vary between 10” and 27” with highly variable flow conditions. Hard to access, off street manholes located in a swamp and on a railway right of way created challenges during deployment. The robust, yet modular SewerVUE multi-sensor pipe inspection system (MPIS) was repeatedly reconfigured during the project to accommodate the challenging site conditions. The sonar results provided accurate sediment volumes and cross sectional restrictions. The Quai George Gorse combined sewer in Boulogne-Billancourt, a southerly suburb of Paris, France is a critical interceptor in the SEVESC operated collection system. This 2200 mm wide and 2700 mm high, irregular shaped (“cunette avec banquettes”) reinforced concrete pipe runs parallel to the Seine river and experiences wet weather overflows during extreme rainfall events. The primary objective of the survey was to quantitatively measure sediment volume and distribution within a 1275.8 m long section. This paper presents the methodology and the results of the inspection. Advanced pipe condition assessment technologies, such as the CCTV, LIDAR and sonar system described in this paper are cost-effective, non-destructive methods that are able to help better refine estimated remaining life of an interceptor, accurately determine overall severity of pipe degradation, as well as provide a basis for improved cost allocation and timing of rehabilitation efforts.