Split Spoon Samples

Mobilize. Bore. Sample. Log. On the high plains grading bench.

Consulting Engineering Field Office

Ground Truth, Logged and Certified Before You Build.

BSA Engineers delivers geotechnical investigation, structural review and site development support from a real core shed standard: every borehole is measured, every sample is racked, and every finding is stamped and signed by a responsible professional engineer.

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Depth Ruler

Readings taken to the half foot on a certified logging scale, reconciled against the driller field notes each shift.

Pocketscope

Field grading of recovered cores before transport, so the bin classification agrees with the laboratory report.

4800+Boreholes Logged

1600+Structures Assessed

2900+Reports Issued

The Boring Log

Six Full-Depth Investigation Strata

Read the ground the way a geologist does, in thin horizontal slices from the surface grade down to one hundred feet. Each stratum below belongs to the geotechnical programme BSA Consulting Engineers, PLLC runs for a typical project, with the field stamp of the responsible bore and a note on what the recovered material tells us before foundation work begins.

0 - 6 FT · TOPSOIL

SB-114

Overburden Layer and Topsoil

The uppermost six feet of the soil column is almost always disturbed material, loose fill, turf and weathered detritus. Our field crews log the color change at the top of every bore to identify where natural grade begins. We measure moisture, root penetration and organic content here first because settlement in this loose layer is a leading cause of cracked slabs. We recommend stripping this mixture and replacing it with a compacted structural fill before any footing is placed, and our bore summary records the exact thickness observed so the grading contractor has a target.

Review geotechnical services

6 - 15 FT · FILL

SB-214

Compacted Structural Fill Horizon

From six to fifteen feet we commonly encounter engineered fill placed during earlier site work, or natural clayey sand that can be reworked. This stratum governs bearing support for shallow foundations. Our lab runs standard penetration tests within this band to calculate the allowable soil bearing pressure under your planned loads, and we compare the numbers against the geotechnical recommendation criteria drawn up during design. When the measured blow counts fall below spec, we either deepen the bearing elevation or specify a grid of piers to reach the competent material beneath, documenting every decision.

Bearing and foundation review

15 - 28 FT · SHEAR

SB-314

Undrained Shear and Swell Zone

The fifteen to twenty-eight foot interval often holds the finer-grained clays that react to seasonal moisture change. We extract undisturbed samples from this depth to run triaxial and consolidation tests, measuring undrained shear strength and the swell index that drives expansive soil movement. These numbers set the depth of foundations, the reinforcement schedule for grade beams and the location of moisture barriers that protect the deck edge. A site with a punishing swell record asks for piers sunk below this active zone, and our report gives the design team the exact depth where the reactive clay stops affecting the footing.

Expansive soil mitigation

28 - 45 FT · WATER

SB-414

Groundwater Observation Zone

Between twenty-eight and forty-five feet we watch closely for perched water and seasonal groundwater fluctuations. Piezometer tips installed at the base of selected bores let us record the standing level over several weeks rather than relying on a single driller glimpse. Rising water reduces effective stress and can soften fine-grained soils, so we evaluate dewatering demand, uplift forces on buried structures and the corrosion exposure of steel piling. The observation period feeds directly into the drainage study, telling the civil team where outfalls must sit and how deep the storm infrastructure can trust the surrounding ground to stay dry.

Groundwater and drainage

45 - 70 FT · GRANULAR

SB-514

Granular Bearing Sands and Gravels

The forty-five to seventy foot band frequently marks the arrival of the dense granular material that makes an excellent deep foundation target. Well-graded sands and gravels here carry high allowable capacities and drain freely, which makes them ideal for drilled shaft termination. We log blow counts across this interval and select the stratum resistance used to size the tip of each pier. If the planned load is heavy, we may specify a foundation pile that locks into this granular layer, giving the structure a rigid seat that is unaffected by the softer clays rising above it. Each shaft is proof-tested against the design value we publish.

Deep foundation selection

70 - 100 FT · ROCKLINE

SB-614

Rockline and Refusal Elevation

Below seventy feet we hunt for the rockline or the dense refusal horizon that terminates driven and bored elements. Shelby tube samples and rock roller bits confirm where auger refusal occurs, and we record the core length and penetration to characterize the transition. This deepest stratum anchors the heaviest structures, from silos to commercial towers, and gives the certification that no softer material continues at depth. Once refusal is logged and the report is stamped, the foundation can be closed out with confidence that the full soil column has been inspected to a defensible engineering standard.

Foundation certification

A bore is only as good as the log that walks it home.

5200 FT

BSA Engineers has logged more than five thousand two hundred linear feet of core across the fields we serve. Every inch is measured on a depth ruler, every split-spoon sample is racked in a numbered core box, and every finding is transcribed onto a permanent record that is stamped and signed by a licensed professional engineer before it ever reaches a foundation design.

The Logging Run

From Mobilization to Certified Report

Our field-to-report sequence mirrors the discipline of a core shed: each phase is a separate station on the logging line, and nothing advances to the next until the responsible engineer signs off the recovered record. The final stick on the rack means your report has been issued.

Mobilize

We confirm access, secure utility clearances and set the drill rig on grade. Site orientation and the bore layout are checked against the survey before the first hole is collared.

Field note: rig set at top of grade.

Bore

Auger string turns to target depths while the geologist records rate of advance, color, odor and any refusal. Split-spoon blows are counted per half foot on the certified handle.

Depth target confirmed at the collar.

Sample

Recovered cores and grab samples are placed into linear wood boxes with sealed lids and labeled depths. Disturbed samples go to clean jars for the laboratory run.

Each tube logged in the tray.

Test

Moisture, Atterberg and strength tests run under controlled conditions. The pocketscope grade is reconciled with the lab to produce a defensible classification column.

Field grade matched to laboratory.

Certify

Results are compiled, the boring log is drafted on the depth ruler scale, and the report is stamped and signed. The issued record carries the responsible engineer seal.

Report Issued after sign-off.

Drill Slots Open for This Mobilization Window

BSA Consulting Engineers, PLLC is booking field crews for the coming construction season. Tell us your site, and we will hold a rig date around your schedule.

Proposals Live

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