To determine soil bearing capacity for helical pier installation, we use a multi-layered approach that combines theoretical engineering, real-time field measurements, and specialized testing. Our process ensures that structural loads are transferred past weak surface soils—such as the expansive clay frequently found in the Centennial and Denver areas—down to competent, load-bearing strata.

We determine capacity using these primary methods:

• Geotechnical Investigation: We analyze soil borings and laboratory samples to identify soil types (such as dense sand or stiff clay), moisture content, and strength parameters like cohesion and friction angles.
• Torque Correlation: During installation, we monitor the rotational force (torque) required to advance the pier. Using the empirical formula Q = Kt x T, we convert this real-time data into an estimate of the soil’s ultimate capacity. This is our primary tool for field verification.
• Theoretical Calculations: Our engineers use bearing capacity equations (such as Terzaghi or Meyerhof) to calculate how much pressure the soil can support before failure, applying a safety factor (typically 2.0 to 3.0) to establish the allowable working load.
• Field Load Testing: For critical structures or high-risk sites, we may perform compression or tension tests (following ASTM standards) to measure exactly how much a pier settles under specific increments of weight.

Because subsurface conditions can change rapidly even across a single job site, these methods allow us to adjust pier depth or helix configuration immediately to ensure long-term stability.

Let us help you get your project started. Please note that estimates are preliminary and subject to change after site inspection and a full scope review. Project outcomes and timelines may vary based on site conditions, permitting, material availability, and unforeseen issues. We recommend you consult a licensed contractor for definitive advice and verify licensure with the Colorado Department of Regulatory Agencies (DORA).

• Soil Bearing Capacity for Helical Piers: A Guide for Centennial