Drilled Shafts and Augered Cast-in-Place Piles Testing Methods for Geotechnical Load Bearing Capacity and Structural Integrity Evaluations

PPT Presentation

Pdf Summary

The presentation reviews integrity and load testing methods for deep foundations, including drilled shafts, auger-cast piles, micropiles, barrettes, and diaphragm walls.<br /><br />Integrity testing identifies flaws—deviations from the planned shape or material—and evaluates whether their size or location could reduce a foundation element’s capacity or durability. Low-strain dynamic Pile Integrity Testing (PIT) classifies results as good, defective, or inconclusive based on shaft reflections and toe signals. Cross-hole Sonic Logging (CSL) assesses concrete between access tubes and can produce two- and three-dimensional images of defects. Thermal Integrity Profiling (TIP) uses thermal wires to map cross-sectional dimensions and identify defects, including in micropiles and large wall elements. Compared with CSL, TIP can provide faster, broader cross-section coverage and avoid some access-tube and inconclusive-result issues.<br /><br />Load testing methods covered include conventional static testing, bi-directional static testing, dynamic testing, and rapid load testing. Bi-directional testing can be used to derive an equivalent top-loading curve and has achieved very high test loads. Dynamic load testing measures force and velocity at the pile top to assess bearing capacity, with analytical methods such as CAPWAP used to interpret results. Rapid load testing applies a short-duration compressive pulse, including through cushioned drop-hammer systems; lateral rapid testing is also noted.<br /><br />The presentation emphasizes that reliable integrity information—including TIP-derived area and length profiles—is important for correctly analyzing load-test data and results.

Keywords

deep foundations

integrity testing

load testing

drilled shafts

micropiles

cross-hole sonic logging

thermal integrity profiling

pile integrity testing

bi-directional static testing

dynamic load testing