The Port of Hamilton, located in Hamilton Harbour, at the far western end of Lake Ontario, is connected to the Great Lakes-St. Lawrence Seaway shipping network. The port handles over 12 million tons of cargo and sees upwards of 700 vessels each year. It is ranked as the busiest of all Canadian Great Lakes ports.
The Hamilton Port Authority retained GHD Engineering Services (GHD) of Quebec to conduct a conditional assessment of Pier 12 West, originally constructed in 1948 using deep arch type sheet piling that was 16m in length. GHD found the wharf to be in very poor condition and beginning to fail. The decision was made to reconstruct the entire west half of the pier in three phases.
Pier 12 is one of the busiest piers at the Port, with over 700,000 tons of cargo handled there each year. The new dock structure is designed for an increased surcharge load capacity of 1,000 pounds per square foot, doubling the original dock’s capacity of 500 pounds per square foot. The new structure is also designed to allow for future maintenance dredging of the adjacent Emerald Street Slip to ensure access by Seaway-draft vessels.
Phase I consisted of rebuilding a 208m long section of the southern half of the pier’s west-facing wall along the Emerald Street Slip. For Phase 1, the Hamilton Port Authority pre-purchased the steel sheet piling, AZ 38-700N, from Nucor Skyline. The purpose of the pre-order was to expedite the delivery through the St. Lawrence Seaway before the closure for winter.
Phase 2 involved rebuilding a 168m long section of the northern half of the west-facing wall, as well as the western half of the north-facing wall of Pier 12. Nucor Skyline supplied the AZ 38-700N sheet pile for this phase of construction.
The next and last phase of the reconstruction of Pier 12, Phase 3, 162m of steel sheet pile was driven into place to complete the new reinforcement of Pier 12. Overall, there was a total of 330m of new steel sheet pile, walers, anchor piles, tie rods, and concrete cope wall. Nucor Skyline supplied 131 pairs of 19.8m long AZ 38-700N sheet piles, as well as 131 #20 Grade 80 tie rods for the last two phases of the project.
The Port of Hamilton sits on reclaimed land that has had mixed-use for the last 50 years. The conditions at the site range from loose silt, down to very hard clay till at the tip of the driven sheets. And, the conditions of the site varied from the west side of the pier to the east side. Dean Construction utilized the newly purchased 500 HPSI vibratory hammer to take the 17.8m to 19.8m long AZ 38-700 sheet pile down to the design toe of 10m into the lake bed. At each phase of construction, the new sheet pile walls were driven within 1m of the existing sheet pile wall.
For more information on using steel sheet piles in marine construction, visit www.nucorskyine.com.