Pine Creek Mine Foundation Lifting & Voidfill

The Challenge

A 15-Inch settlement with a 38-foot retaining wall cribbing

The project involved stabilizing a commercial building that was settling by as much as 15 inches in one corner—the most severe point of damage. This structural compromise threatened the building’s integrity and functionality. Complicating the project was an extensive underground timber cribbing system, part of a 38-foot retaining wall, which encased the building’s footing. The removal of this timber posed a significant challenge, making access to the footing for pier installation exceptionally difficult.

Key Facts

The Solution

Installing 30 push piers and injecting expanding polyurethane.

30 push piers were installed along the building’s back wall perimeter and partially down the sidewalls to provide robust support. Then expanding polyurethane was injected beneath the concrete slab to fill voids created during the lift and ensure uniform stabilization. This combination of solutions leveraged both mechanical and material innovations to ensure a safe and effective lift.

The Impact

A 10-Inch lift achieved in just one week.

Although the target lift was 15 inches, engineers carefully stopped at a 10-inch elevation to avoid over-tensioning the building’s structural rods. This adjustment preserved the building’s integrity while stabilizing the foundation. The project was completed efficiently within just one week, minimizing disruption for the client and ensuring long-term stability.