Dynamic Load Testing on Helical Piles-PPT Presentation

PPT Presentation

Pdf Summary

The presentation reports on a DFI-funded initiative to evaluate dynamic testing of helical piles. Funding included $27,250 in approved project costs and $95,432 in in-kind support. The work comprised a desk study, field testing, and planned presentation or publication. The presenter notes that relatively few publications address dynamic testing of helical piles.<br /><br />Field tests were conducted at two sites: a sandy-soil site in Denver, Colorado, and a clay-soil site in Centralia, Missouri. Six piles were tested at each site in September 2025. The piles varied in shaft type, helix configuration, installation depth, and torque. Drop tests used impact heights of 6–24 inches in Denver and 6–21 inches in Missouri, with cumulative observed sets varying among piles.<br /><br />The presentation discusses practical testing considerations, including pile instrumentation and preparation, pile-cap design, plywood cushions, lateral restraint, permanent displacement, slack in piles with extensions, signal matching, and modeling soil around the helices.<br /><br />Dynamic testing can allow multiple piles to be tested in one day, assess high loads with relatively little additional effort, and be useful in confined spaces where a reaction beam is impractical. It may also help identify displacement caused by connection gaps closing. However, it cannot evaluate soil creep under sustained loading or directly determine tension capacity. Reliable analysis requires experience and may involve engineering judgment; testing may not be cost-effective for projects with only one load test.

Keywords

helical piles

dynamic testing

DFI-funded initiative

field testing

soil conditions

drop tests

pile instrumentation

signal matching

permanent displacement

engineering judgment