Adjacent Top-Loaded Bi-Directional Test And Conventional Bi-Directional Load Test Results

Video Transcription

Video Summary

The presentation compares a conventional bidirectional pile test with a top-loaded bidirectional test, which places the jack and instrumentation above ground and uses bars to transfer load to the shaft and base bearing plates. At a site in Solon, Ohio, a 2021 top-loaded test on a 3-foot-diameter, 30-foot shaft was compared with a conventional test conducted nearby in 2017, with both tests’ break planes at the same depth.<br /><br />The load–displacement results were broadly comparable, supporting the top-loaded method. The top-loaded test reached higher loads, partly because it had greater jack travel and encountered stronger end-bearing response. Additional instrumentation showed generally uniform load distribution, although one base mobilizer bar carried less load than the others, and bar loads differed from jack and load-cell readings by up to 12%. The presenter noted possible effects from bar alignment, concrete intrusion, and bar movement. The method may reduce costs, especially when multiple tests allow equipment reuse.

Keywords

bidirectional pile test

top-loaded test

load-displacement

end-bearing response

Solon Ohio