Common questions about drilled piers, foundation design, and the drilling process — answered by 30+ years of field experience.
What is a drilled pier and how does it differ from a driven pile?▼
A drilled pier (also called a drilled shaft or caisson) is a deep foundation element formed by drilling a cylindrical hole into the ground, placing reinforcing steel, and filling with concrete. Unlike driven piles which are hammered into place, drilled piers are cast in place — eliminating noise and vibration concerns, and allowing for inspection of the bearing stratum before pouring. They're the preferred solution for high-load structures, sites near sensitive existing structures, and projects requiring rock socketing.
What diameter and depth can you drill?▼
We drill any diameter your project requires — from compact micropiles up to large-diameter caissons and beyond. Depths routinely reach 120+ feet, and we have the equipment and experience to go deeper when project conditions call for it. There's no hard upper limit on what we can engineer a solution for.
What is rock socketing and when is it required?▼
A rock socket is a portion of the drilled shaft that extends into the underlying rock to develop additional bearing and side friction. Rock socketing is typically required when surface soils can't develop the load capacity needed, when structural design requires a known bearing stratum, or when uplift resistance is critical. Socket lengths typically run 1.0–3.0× the shaft diameter depending on rock quality and load demands.
What field problems can affect drilled pier construction?▼
The most common challenges include caving soils (loose sands or saturated clays sloughing into the hole), groundwater inflow requiring casing or drilling fluids, obstructions like buried debris or boulders, and differing site conditions where actual soil profiles vary from soil reports. Our crews are trained to identify these conditions early and adjust methods — temporary casing, polymer slurry, or alternate drilling techniques — to maintain shaft integrity.
When should I use micropiles instead of drilled piers?▼
Micropiles are the right choice when access is limited (low headroom, tight footprint), when underpinning an existing structure, when subsurface conditions include obstructions, or when high capacity is needed in a small diameter. Typical applications include retrofits, seismic upgrades, foundation repair, and tieback systems. They install with minimal vibration and disturbance.
How do tie-back anchors work?▼
Tie-back anchors are drilled and grouted tendons (steel strands or threaded bars) that resist lateral earth pressures by transferring loads back to a competent soil or rock zone behind the active failure wedge. They're standard for retention walls, soldier pile shoring, and slope stabilization. Each anchor is proof-tested to verify capacity before being locked off.
What documentation do you provide?▼
Every shaft we install gets a complete drill log: pier number, diameter, total depth, top of rock and rock socket length, casing depth, concrete volume placed, soil and rock conditions encountered, rebar cage details, and the inspector/operator on duty. These logs are submitted daily and compiled into a final as-built record at project closeout — ready for your project file or any agency review.
Do you handle spoils disposal?▼
By default, spoils removal and disposal is the GC's responsibility — we stockpile spoils at a designated location on-site. If your project requires us to handle disposal, we'll quote that as a separate line item based on volume, distance to dump, and any hazardous classification. Contact us to discuss scope.
