Metrolinx, an agency that manages and integrates road and public transport in Ontario, launched a regional transportation plan, “The Big Move,” which is a 25-year, $50 billion plan for a coordinated, integrated transportation and transit system in the Greater Toronto and Hamilton area. Two projects that formed part of The Big Move include the Hurontario (HuLRT) and Hamilton (HaLRT) light rail transit (LRT).
Managing utility relocations typically presents one of the largest risks associated with delivering major capital infrastructure projects. It is important to have accurate, reliable information on subsurface utilities to mitigate and manage utility risk.
Since both routes are located on existing utility-congested road corridors, T2 Utility Engineers (T2ue)* provided Utility Coordination Services and Subsurface Utility Engineering (SUE) investigations following American Society of Civil Engineers (ASCE) 38-02 principles to accurately locate and map the subsurface infrastructure.
To augment the conventional SUE geophysical technologies, T2ue implemented advanced SUE technologies to give greater certainty to the horizontal and vertical locations of the subsurface utility infrastructure, including:
- Multi-channel ground penetrating radar (MCGPR)
- 3D modeling
All utility alignments were surveyed, and the information was extrapolated into a composite utility drawing that showed the existing utilities at the appropriate Quality Levels in accordance with ASCE 38-02, “Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data.”
After compiling the SUE data, T2ue generated 3D models of the existing subsurface utilities for the two LRT projects. The 2D composite plans and 3D composite utility model were utilized by the project Utility Coordinators to create detailed conflict matrices. The matrices allowed the team to select strategic test holes at critical locations to improve the accuracy of the subsurface utility infrastructure locations.
Once all the test hole information was gathered utilizing a vacuum excavation equipment, the composite utility plans/models were updated. Armed with accurate composite utility plans/models T2ue’s utility coordinators performed utility impact analyses that resulted in updated, reliable utility conflict matrices, that could be used by the proponents on the team bidding these P3 projects.
* T2 Utility Engineers is a wholly owned subsidiary of Cardno