Drilled Shafts
Drilled shafts support heavy structural and civil projects where high loads, rock, groundwater, casing, reinforcement, or difficult ground conditions demand specialized drilling equipment and tooling.
Pacific Foundation executes complex drilled shaft foundations for major infrastructure across the West. Clients turn to Pacific when difficult ground and demanding structural requirements call for experience and quality in the field.
Large Diameter Drilled Shafts
Pacific Foundation executes large-diameter drilled shafts for major infrastructure where the design demands deep axial capacity and substantial lateral resistance. These reinforced concrete foundations transfer structural loads into competent material when shallow systems or smaller piles cannot meet the project requirements.
Where groundwater or unstable ground threatens the excavation, Pacific develops the casing or slurry approach needed to maintain control through concrete placement. Pacific establishes that execution strategy early, keeping the project plan tied to how the shaft will actually be built.
Choosing The Right Deep Foundation Approach
Use drilled shafts where a structure needs high axial or lateral capacity from a large reinforced-concrete foundation. They can also form rock sockets and reduce installation vibration compared with driven piles.
Driven Piles
Driven piles may fit where pile type, driveability, vibration limits, testing requirements, and access support a driven system. Drilled shafts may fit better where the project needs larger reinforced concrete elements, rock sockets, lower vibration, or more excavation control.
Micropiles
Micropiles are often considered for retrofit, underpinning, low-headroom, or tight-access work. Drilled shafts are usually considered where larger equipment can reach the work and the design benefits from a larger-diameter foundation element.
Auger Cast / CFA Piles
CFA and auger cast piles can fit repetitive pile layouts where continuous installation, spoil handling, low vibration, and inspection requirements align with the soil profile. They are not interchangeable with drilled shafts.
Displacement CFA Piles
Displacement CFA piles may fit where reduced spoils and lateral soil displacement are useful and the ground can accept the installation method. They should not be treated as conventional CFA piles or drilled shafts.
Ground Improvement / Rigid Inclusions
Ground improvement or rigid inclusions may be more appropriate when the goal is settlement control or composite ground behavior rather than a fully pile-supported foundation system.
Equipment Matched to the Work
Successful drilled shaft construction starts with the right equipment and tooling for the conditions on site. Shaft diameter, depth, subsurface conditions, access, working platform capacity, reinforcement, and concrete placement all influence how the work is executed.
Pacific matches equipment, tooling, and drilling methods to the conditions below grade. Soil profile, shaft geometry, groundwater, access constraints, and production requirements all influence the equipment used to complete the work safely and efficiently.
Those decisions carry through estimating, planning, and field execution, helping reduce surprises once drilling begins.
Bauer BG 33 H
Heavy vertical drill rig used for CFA tooling, drilled foundation work, and production pile installation where pile size, access, and sequencing need coordinated field control.
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Bauer BG 40 V
The Bauer BG 40 V is a large vertical drill rig built for deep and large-diameter foundation drilling.
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Bauer BG55
The Bauer BG55 is a heavy vertical drill rig used for large-diameter and deep-drilling foundation work.
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Bauer BG 24 H #2026
The Bauer BG 24 H is a hydraulic foundation drill rig in the mid-size shaft-drilling class.
View equipmentFeatured Drilled Shaft Projects
Published drilled shaft work includes bridge, water-infrastructure, dam, industrial, utility, and public projects where ground conditions, access, reinforcement, concrete placement, and inspection shaped execution.
Ridgefield, WA / Bridges & Transportation River S Bridge Replacement
Pacific Foundation supported the River S Bridge replacement with 10-foot and 5-foot diameter drilled shafts installed from a barge using a Bauer BG55.
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Portland, OR / Commercial & Mixed-Use Foss Maritime Dock
Pacific Foundation pre-bored pile locations from a barge-mounted Bauer BG 24 H, using 36-inch temporary casing and grout to support installation of the permanent dock piles.
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Pullman, WA / Electric Power Lower Granite Dam
Pacific Foundation installed 32 drilled shafts, each 54 inches in diameter, with 48-inch-diameter rock sockets. The shafts were installed over water through overburden and hard bedrock.
View projectDrilled Shaft Planning Questions
When are drilled shafts preferred?
Drilled shafts are often considered where the structure needs larger reinforced concrete foundation elements, deep axial or lateral capacity, rock sockets, lower vibration than driven piles, or a foundation system that can be planned around controlled excavation and concrete placement.
What site conditions affect drilled shaft construction?
Groundwater, caving soils, cobbles, boulders, rock, access, work platform stability, reinforcement congestion, concrete delivery, inspection requirements, testing, and adjacent work can all affect the drilled shaft plan.
When is casing required?
Casing may be required when the excavation needs support, groundwater or unstable soils affect shaft stability, or the specifications call for a casing method. The casing assumption should be reviewed against the geotechnical report and expected drilling conditions.
When is slurry required?
Slurry may be considered when a wet or unstable excavation needs support before reinforcement and concrete placement. Slurry assumptions affect cleanout, inspection, concrete placement, documentation, and sequencing.
How do drilled shafts differ from CFA / auger cast piles?
Drilled shafts are excavated large-diameter elements that are reinforced and concreted according to the shaft plan. CFA / auger cast piles are installed with a continuous auger process and are not interchangeable with drilled shafts. Method selection depends on loads, soil profile, diameter, access, spoils, testing, reinforcement, and production requirements.
What does Pacific need to review a drilled shaft scope?
Send structural drawings, specifications, geotechnical report, shaft schedule, load information, access constraints, work platform assumptions, groundwater information, reinforcement details, inspection/testing requirements, and schedule constraints.
Discuss Your Drilled Shaft Scope
For early review or defined-scope estimating, send the drawings, specifications, geotechnical report, shaft schedule, load requirements, access constraints, work platform assumptions, groundwater information, reinforcement details, concrete requirements, inspection criteria, testing requirements, known obstructions, bid date, and schedule constraints.
If the foundation method is still being evaluated, Pacific can review the drilled shaft scope against driven piles, micropiles, CFA / auger cast piles, displacement CFA piles, rigid inclusions, or ground improvement so the project team can align the method with the site conditions and structural requirements.