In Las Vegas, the shallow geology is deceptive. You see fill, caliche, and desert alluvium, but below that, many sites have loose silty sands and soft clays that collapse when wet. Standard SPT samples get disturbed — you lose the true structure. That is why we use undisturbed sampling (Shelby tube) to extract intact cores for consolidation and shear tests. Without it, settlement estimates for strip malls or multi-story buildings along the Strip become guesswork. We combine this with a placa de carga to verify modulus values on site.
Shelby tube sampling preserves the soil fabric that SPT destroys — essential for collapse and consolidation analysis in Las Vegas alluvium.
Service characteristics in Las Vegas
- Advance borehole to target depth
- Clean out cuttings
- Push Shelby tube hydraulically
- Seal and transport vertically
Demonstration video
Critical ground factors in Las Vegas
Las Vegas expanded fast from the 1980s onward. Many residential subdivisions sit on fill that was never properly engineered. Undisturbed sampling (Shelby tube) in those fills reveals whether they are loose or collapsible. If you skip this step, you risk differential settlement of slabs and foundations. We have seen houses in Summerlin and Green Valley crack because the fill settled unevenly after a wet winter. A single Shelby tube boring can save tens of thousands in repairs.
Our services
We offer two types of undisturbed sampling in Las Vegas tailored to project scale and soil type.
Conventional Shelby Tube Sampling
For routine projects — residential, commercial pads, retaining walls. 3-inch tubes pushed in 5-ft increments. Lab includes consolidation and collapse index.
Fixed-Piston Shelby Tube Sampling
For soft clays and loose silts where cohesion is low. A piston inside the tube prevents sample loss during withdrawal. Used on the Strip for deep foundations near the water table.
Frequently asked questions
What is the difference between SPT and Shelby tube sampling?
SPT (ASTM D1586) gives a disturbed sample and blow count for relative density. Shelby tube gives an undisturbed core for lab tests like consolidation, collapse, and undrained shear. For settlement analysis in Las Vegas alluvium, you need the tube sample.
How much does Shelby tube sampling cost in Las Vegas?
Typical cost ranges between US$440 and US$960 per tube, depending on depth, soil conditions, and whether you need fixed-piston tubes. Price includes field push, sealing, transport, and lab testing for one sample.
Can Shelby tubes be used in gravelly soils?
Not reliably. If the soil contains gravel larger than 1/4 inch, the tube edge can bend or the sample gets disturbed. In those cases we use block sampling or large-diameter coring. The site conditions dictate the method.
How long does it take to get results from undisturbed sampling?
Field work takes one day per boring. Lab testing — consolidation and collapse — takes 7 to 14 days depending on the number of load increments. We provide interim field logs within 48 hours.