STEP 2: Helical Pile Design

July 10, 2026

STEP 2: Helical Pile Design Parameters

Using Chance Helical Pier Methodology: Enter your design requirements below. The system will calculate bearing capacity using the equation Qh = Ah × (9c + q×Nq) and recommend an optimal pile configuration.

Soil Data from STEP 1:

Boring Log: 1

Location: 1602 South 2nd Avenue, Marshalltown, IA

Soil Layers: 4 layers

Groundwater: 10.0 ft

View Full Soil Data

Design Requirements

AI-Powered Design: Our AI will analyze your soil conditions and automatically recommend the optimal shaft system, depth range, and multiple design alternatives. Just specify your load requirements below.

Design Load (kips) *

Required allowable load (1 kip = 1000 lbs)

Safety Factor *

Typical: 2.0 (conservative: 2.5-3.0)

Note: Leave these blank to let AI recommend optimal values based on soil conditions.

Force Specific Shaft System (Optional)

Override Minimum Depth (ft)

Override Maximum Depth (ft)

Back to Step 1 Data

Design Methodology Reference

Bearing Capacity Equation:

Qh = Ah × (9c + q×Nq) ≤ Qs

Where:

Qh = Individual helix bearing capacity
Ah = Projected helix area (sq. ft.)
c = Soil cohesion (ksf) - zero for sand
q = Effective overburden pressure (ksf)
Nq = Bearing capacity factor (from friction angle)
Qs = Mechanical strength limit

Design Principles:

Deep foundation mode: Top helix at 5D or 5 ft depth (whichever is deeper)
Helix spacing: 3 × diameter of lower helix
Total capacity: Sum of individual helix capacities
14-inch helices: 20% capacity reduction per code