Predictive Modeling of Multiple Helical Lead Section Configurations through a Helical Pile Test-PPT Presentation

PPT Presentation

Pdf Summary

The presentation explains how measured installation torque from a helical pile can be used to model soil strength and improve construction decisions.<br /><br />During installation, the pile’s helix flights and shaft encounter soil resistance as equipment applies torque and downward force. Because torque generally increases with depth, piles are advanced until they reach a specified target. Accurate, in-line torque measurement is emphasized: different lead-section configurations can reach the same target torque at different depths, so torque records help determine whether soil conditions or pile geometry explain the difference.<br /><br />Helical pile capacity is empirically related to installation torque through a torque factor, Kt. The presentation proposes using this relationship to infer soil strength from a test pile. First, install a pile with a known lead configuration while recording torque by depth. Build a soil model in HeliCAP using site boring information, including soil types and groundwater conditions. Then adjust parameters such as N-values, cohesion, friction angle, and unit weight until modeled torque aligns with measured field torque. Cohesive and granular soils may develop capacity differently and should be represented accordingly.<br /><br />Once the model matches the test pile, use it to predict how alternative lead configurations will perform and help select an appropriate configuration and pile length for project loads. The approach can support more accurate construction-phase changes than relying on target torque alone.<br /><br />Key takeaways are to measure torque for every pile, understand the interaction between pile geometry and soil, and use field-test data to estimate soil strength and inform decisions.

Keywords

helical pile

installation torque

soil strength

pile capacity

torque factor

HeliCAP

soil model

lead configuration

construction decisions

groundwater conditions