Drilled Shafts

Drilled shafts, also known as caissons or drilled piers, are a deep foundation solution used when high load-bearing capacity and minimal settlement are critical. At Pacific Foundation, we install drilled shafts across a wide range of project types—from transportation and energy infrastructure to industrial facilities and marine structures.

While every drilled shaft design is tailored to project-specific requirements such as diameter, depth, cage design, and load type, the construction process remains consistent and precise.

How We Build

Using a vertical drill rig—typically a Bauer BG series or similar—we advance a steel casing into the ground, either partially or full-depth, depending on soil conditions and design requirements. We then excavate the shaft using a drilling tool like a core barrel or bucket, often employing slurry or casing to maintain borehole stability in soft or unstable soils.

Once the shaft reaches target depth, we clean the base to ensure strong bearing capacity. A reinforcing steel cage is carefully lowered into the excavation, and concrete is placed via tremie or pump, displacing the slurry and forming a solid, high-strength shaft.

For rock sockets or shafts requiring extreme depth or capacity, we employ specialized tooling and monitoring to ensure precision in every phase of the build.

Why Drilled Shafts?

Compared to driven piles or other deep foundations, drilled shafts offer:

• High Load Capacity — Ideal for heavy vertical, lateral, and overturning loads

• Minimal Vibration — Suitable for sensitive structures and urban environments

• Deep Penetration — Effective in reaching competent bearing strata or rock

• Custom Geometry — Large diameters (up to 12 ft) and variable depths

• Versatility — Adaptable to changing soils, groundwater, and design needs