Project Summary
Formula was selected to deliver the Holt Creek Bridge No. 10543 Replacement project, located along the Cowichan Valley Trail approximately 7 km west of Duncan, BC. This project involved the full replacement of an aging timber trestle with a modern, multi-use bridge, supporting pedestrians, cyclists, and equestrians along the Trans Canada Trail corridor. A primary objective of the new bridge was to provide access for fire fighting trucks and equipment along an otherwise inaccessible trail.
The project scope included the demolition and removal of the existing timber structure and the construction of a new single-span steel plate girder bridge with a timber deck and railings. The bridge spans a deep canyon and required innovative access and erection planning due to the remote location and sensitive environmental setting. One of the most innovative aspects of this project was repurposing the main steel span as a gantry crane to dismantle the existing structure.
Throughout the project Allnorth Consultants provided construction engineering including girder erection and demolition planning of the existing structure.
Scope of Work:
- Demolition and removal of the existing timber trestle bridge
- Construction of a new single-span steel plate girder bridge with timber decking and railings
- Spanning a deep canyon, requiring innovative access planning and erection techniques in a remote, environmentally sensitive area
- Approach trail reconstruction on both sides of the bridge, including:
- Embankment construction
- Granular placement and final surface restoration
- Environmental protection works, including:
- Erosion and sediment control
- Riprap installation for creek protection
- Full compliance with Fisheries and Oceans Canada and provincial environmental approvals
Design-Builder Responsibilities:
- Complete engineering and constructability planning
- Topographic and legal surveying
- Quality management and environmental monitoring
- Traffic control and public safety planning
- Permitting and stakeholder engagement
- Development of tie-in access roads and laydown areas with minimal site disturbance
The Holt Creek project was successfully self-performed by Formula Contractors in a remote, environmentally sensitive, and logistically challenging location. Despite these complexities, the work was completed without any major safety incidents or environmental non-conformances. This project further reinforced Formula’s reputation for technical excellence, environmental stewardship, and reliable, high-quality project execution.
Challenges Overcame:
- Extremely challenging access utilizing existing highway, forestry roads and overland using skid trails and the Cowichan valley Trail.
- Dismantling and removal of the very old truss with extremely limited access and without depositing any hazardous materials into the Holt creek.
Successes:
- Completed on time and on budget with 0 time losses due accidents and injuries and no reportable environmental incidents.
- Innovative method of using the existing structure to support the launch of the new steel span and then using the new steel span as an overhead crane to assist with demolition of the existing bridge.