test cell

Soil Stabilization for Test Cell Excavation

Case description

A multinational equipment manufacturing company required a deep foundation to be excavated through granular soils with a high water table for installation of a new test cell within an existing plant facility, without disrupting adjacent equipment operations or causing settlement of building structures. Due to space constraints and ongoing equipment operations, conventional deep foundation shoring systems could not be utilized within the existing manufacturing plant.

Solution

A sleeve pipe grouting plan was designed and implemented by our grouting engineers to consolidate perimeter walls around the proposed deep excavation using water-activated polyurethane resin.

Where possible, sleeve pipes were installed at a spacing of 18 inches apart to a depth of 10 feet around the perimeter of the proposed excavation. At locations where various obstructions precluded sleeve pipe installation, conventional open drill holes were systematically drilled and injected using down stage techniques to complete soil stabilization around the perimeter of the excavation.

Water-activated, low-viscosity polyurethane resin with low accelerator dosage was systematically injected by our grouting specialists at a flow rate of 1/2 gallon per minute through each sleeve pipe port and drill hole to effectively permeate and stabilize the surrounding soil.

Upon completion of soil stabilization grouting work, the general contractor was able to proceed with test cell excavation and foundation construction as planned without encountering any delays or problems.

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deep shaft construction jobsite toronto

Deep Shaft Construction through Quicksand Soil Conditions

Case description

Construction of a deep shaft for repair of the Coxwell Trunk Sewer encountered ultra-fine quicksand soil conditions at the interface between the original tunnel lining and shaft excavation that could not be dewatered using conventional well points.

Shaft wall construction consisted of secant piles down to the top of existing sewer tunnel, with subsequent jet grouting to close residual areas surrounding and beneath the existing sewer tunnel. Due to complex geometry at the shaft lining to tunnel lining interface, residual layers of ultra-fine soils remained under high hydrostatic water pressure that flowed into the shaft excavation and delayed construction work.

Solution

Based upon past experience with other similar projects, Peter White developed a drilling and grouting plan involving sodium silicate injection, in conjunction with the use of water-activated polyurethane resin, to systematically consolidate and stabilize water-bearing, ultra-fine soils so that shaft excavation could proceed in a safe and controlled manner.

Shaft excavation crews, with assistance from Peter White’s¬†technical personnel, were able to successfully stabilize quicksand conditions and proceed with the remaining excavation work required to complete construction of the Coxwell Trunk Sewer Bypass.

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