Transparent and defensible Assessment Management Strategy prepared for Saskatchewan Association of Rural Municipalities

Structure on Saskatchewan Bridge Inventory

In the last issue of AE Today, we reported that the Saskatchewan
Association of Rural Municipalities in conjunction with Saskatchewan Highways and Transportation (SHT) had retained Associated Engineering to complete a bridge and culvert strategic asset management study on their behalf. The Saskatchewan Association of Rural Municipalities owns and maintains 3900 bridges and culverts located throughout Saskatchewan.

SHT required a strategic asset management plan for managing and maintaining the structures. A key objective of the study was to develop a unified service level and performance objectives for the structures. In addition, SHT wanted to be able to establish a methodology for prioritizing structural repairs or rehabilitation so that appropriate funding could be determined.

Data Management
To establish an asset management strategy, Associated Engineering first had to assess and document the available structures inventory. SHT maintains one database for each class of structure with a structures inventory and a rehabilitation history for each structure. Information contained in the database included location for some of the stuctures, condition, and rehabilitation and repair history. In addition to SHT information, AE also needed to cross reference the following data:

• Saskatchewan Highways and Rural Municipal Road Network
• Provincial Hydrology such as creeks and rivers
• Populations by Area and R.M.
• Truck and Blended Average Annual Daily Traffic, (A.A.D.T.) values
• Road Classes
• Posted Grain Haul Routes
• R.M. and Populated Area Boundaries
• Additional Data for Bridge and Culvert Locations
• Rural Section, Township and Range Delineators
• Modeled Grain Haul Routes
• Primary Haul Corridors.

The above information was joined to information on the bridge and culvert structures using advanced spatial Structure Query Language programming. Adjacent information was snapped to each structure based on its proximity to known values. These values were then written back to the project database for evaluation. In addition, structure value, expected lifespan and depreciated value for each structure were developed using industry standard, Saskatchewan-specific replacement costs. This allowed for the construction of a life-cylebased sustainability analysis of all structures. Values generated were then compared to the relative risk and liability associated with each structure. Due to the volume of information, SHT also sought an improved method for data management. With expertise from Asset Management Specialist, David Watt and GIS Specialist, James Burn, the AE team developed a secure, web-based GIS tool to allow all project partners to view and query the bridge and culvert
inventory during the project. This WEB GIS is a purpose-built, non-proprietary database and decision-making system which
Saskatchewan Highways and Transportation can integrate into its asset management system.

System Verification
To test the accuracy of the bridge inventory database, AE staff conducted six bridge assessments. The bridge inspections also
allowed us to determine the current condition of the structures compared to information in the database, as well as load ratings.
Bridges were selected based on diversity of structural type, age, and geographical location. The inspections identified some inconsistencies between the repair history and condition of the existing structures and the documented condition in SHT’s database. Maintenance and repairs were also identified.

Risk and Priority Assessment
The next step in the study involved developing an objective rating system for structures to allow SHT to assess the risk and assign priorities for a structures inspection, maintenance, and replacement program. A secondary consideration at the outset of the study was the examination of the feasibility of the elimination of structures on Class 7 roads based on their respective demands. AE staff in conjunction with the project team developed weighted criteria, as shown in the table on page 8, for evaluating the structures in relation to public risk and service. (continued on page 8)