Unique Strategy Keeps Concrete Dock Operational During Repairs
A Southern refinery for a major oil and gas company had a concrete dock built in 1910 that needed significant repairs. The 3,000-foot-long dock is connected to an intercoastal waterway and serves as the off-load point for crude oil and the on-load point for petroleum products with ships arriving and departing daily.
An investigation of the dock’s structural integrity revealed substantial erosion on the bottom-side. The concrete beams supporting the dock had visible damage – including rebar that was hanging down to the water. Selecting an effective repair method was essential to the continued operation of this facility as a closed dock would preclude the daily traffic to and from the refinery. STRUCTURAL recommended performing the repairs from the dock – an approach that would minimize the disruption of the traffic to and from the refinery.
Careful planning of every detail was required. Using diesel-powered concrete saws, segments measuring 4-foot by 6-foot were cut and connected to an A-frame for removal. From the A-frame, the pieces were removed to a dolly and wheeled to the end of the dock where a small crane hoisted them into trucks. In total, the team removed 1,500 cubic feet of concrete.
Different to traditional projects, the deck to be replaced was completely supported on top of the pile cap structures through the use of coil rods; stay-in-place, fiberglass, corrugated decking that was saltwater-resistant; and 4 by 6 lumber. This system served as a work platform, concrete debris containment mechanism and formwork. A 58-meter concrete boom truck was utilized to place the concrete, but placement was extremely challenging due to a flood protection wall that hindered access. From where the truck was located, the concrete had to be pumped 160 feet.
Crews worked around the clock, seven days a week – completing work in two-and-a-half weeks. The owner was so pleased with the results that the team began repair on another dock section the following week.