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Maple Leaf Foods Stunning Pit Shoring

Maple Leaf Foods Stunning Pit Shoring
Date: 2015

In the expansion of the Maple Leaf Foods pork processing plant in Brandon, Manitoba, AGRA Foundations Limited was contracted by Epstein Construction Inc. for the construction of two concrete pits in an approximately 15 m x 6 m x 10 m deep excavation. The work area was surrounded on three sides by existing buildings with footings that could not be undermined , leaving only a narrow access to the construction zone. The excavation was made in moist, loose sand that became wet below 3 m depth and extended to about 4.5 m deep, underlain by 10.5 m of stiff to very stiff clay till that offered medium plasticity with intermediate sand and gravel layers that ranged from very stiff to hard, starting at 10 m depth.

Solution:

The AGRA team presented a complete solution involving the design and construction of 78 each 750 mm dia. x 12 m secant piles complete with temporary steel waler system to effectively retain the soils surrounding the concrete pit. 22 secant piles, each 610 mm in diameter and 7.5 m deep, also designed and constructed by AGRA for supplemental shoring, allowed for the realignment of an existing sewer line that previously obstructed the work area. The crew mobilized one drill rig with 750 mm and 880 mm segmental casing. The AGRA crew successfully completed the project despite icy temperatures of -30 degrees Celsius.