Economical design is a buzz word in today’s engineering community, and since the performance of a structure relies on a stable foundation, foundations have historically been conservatively designed. Conservative foundation design typically results from poor or limited subsurface exploration, variable site conditions, uncertainty in static modeling and/or aversion of risk. Conservatism, however, can be reduced by confirming the capacity of a foundation element prior to or during construction. Field verification of axial capacity generally results in reduced factors of safety or increased resistance factors depending on the design methodology.
Static load testing has been the long-time standard for deep foundation capacity verification but is generally limited to a single test or a few wide-spaced tests due to cost. High-strain dynamic load testing (DLT) is a proven and economical alternative for estimating the static axial capacity of a foundation element. DLT is commonly used on driven piles but can also be used to estimate the static axial capacity of auger-cast piles and drilled shafts using modified pile hammers or custom drop hammers. Additional benefits for driven piles include measuring pile stresses and hammer performance during driving.
Geotechnology owns three Pile Driving Analyzers (PDA) and has been providing DLT services to the Midcontinent since the mid-1990s. Our DLT related services include:
- Foundation design recommendations including appropriate factors of safety or resistance factors
- Drivability analyses using GRLWEAP software (i.e. preconstruction wave equation analysis modeling)
- Testing program recommendations and planning (i.e. locations, number of tests, etc.)
- DLT specification development
- High-strain dynamic testing
- Signal matching analyses using CAse Pile Wave Analysis Program (CAPWAP)
Please email Craig Kaibel, P.E. for more information or call 314-997-7440.