Client: City of Ottawa
Location: Ottawa, Ontario
Year Completed: 2015
The 3.6 m x 2.4 m concrete box culvert conveying Barrhaven Creek under Prince of Wales Drive, in the south end of the City of Ottawa (City), was a reinforced concrete frame culvert that required renewal due to insufficient hydraulic capacity and severe structural deterioration. The new culvert had to be designed to meet current hydraulic design requirements and was to be lengthened substantially to accommodate a future widening of Prince of Wales Drive. J.L. Richards & Associates Limited (JLR) was the Prime Consultant and provided complete structural and civil engineering consulting services, management of subconsultants, complete contract administration and full-time inspection services. Specific services provided by JLR included all preliminary and detailed design, hydraulic analysis and design to size the new bridge culvert and the upstream cast-in-place transition section; structural analysis and design to CHBDC; construction staging and sequencing and traffic considerations; consultation and stakeholder engagement; approvals; drainage design; road safety assessment and guide rail design; slope stabilization and erosion/sediment control measures; flow management design including sizing for gravity by-pass pipes; utility coordination; tender document preparation; contract administration and inspection. closure.
Built in stages between the early 1940s and 1960s, the existing culvert structure conveying Nepean Creek under Prince of Wales Drive (at Fisher) to the Rideau Canal was a composite section consisting of a structural plate corrugated steel pipe (SPCSP) culvert and a concrete frame culvert. Erosion and deterioration of the structure had caused collapse of the northeast wingwall and a slope failure in the east (downstream) embankment. Due to the significant depth of the structure, open cut renewal of the composite culvert would have triggered a complete and extended closure of the roadway, unacceptable due to the high traffic volumes. JLR developed an innovative renewal approach not considered in the functional design options review that included driving a new concrete pipe tunnel then lining the existing structure with a new concrete pipe. This option provided the advantages of a long expected service life, reasonable capital cost, and flexibility in construction staging, such that flows in the watercourse could be conveyed through the existing culvert during tunneling, then through the newly constructed tunnel during slip-lining. JLR carried out the hydraulic design to size both the new tunnel and the slip-lined pipe. A complex structural design for the cast-in-place upstream and downstream headwalls and wingwalls was required, given the embankment height and the preexisting slope failure on the downstream side. Relocation of a major vital gas transmission main was required prior to construction.