Role Advanced Technology - Resolve Inherent Dichotomy In High Strain Dynamic Testing

- Organization:
- Deep Foundations Institute
- Pages:
- 12
- File Size:
- 1107 KB
- Publication Date:
- May 1, 2022
Abstract
NCHRP Synthesis 418 (2011) entitled, “Developing Production Pile Driving Criteria from Test Pile
Data” details the occurrence of dichotomy between pile Skin resistance and pile Tip resistance
mobilizations at different times for different hammer blows during pile driving operations. With
increasing usage of High Strain Dynamic Testing (HSDT) the engineering community started paying
more attention to this occurrence of dichotomy resulting in overdriving, pile damage, increased claims,
and loss of time. To overcome the dichotomy limitations of HSDT, NCHRP recommends, “the use of
superposition to combine the back-calculated tip resistance from a blow on initial drive or from redrive
with the back-calculated skin resistance from the early blows at the beginning of restrike”. However,
the current practice of external mounted gauges and signal matching for a single blow are unable to
evaluate independently the Skin resistance and Tip resistance to achieve the goal of determining the
optimum Total Pile Capacity using the superposition. This paper discusses advancements of science
and technology with sensors embedded at the pile top and pile tip, the data collected is analyzed by the
state-of-the-art FDOT Method to determine Skin and Tip resistances independently for every blow.
Independent Tip and Skin resistances each with a Resistance Factor can be summed up to obtain
optimum Total Pile Capacity. Additional benefits of determining independent Skin and Tip resistances
include obtaining lost skin capacity due to scour, due to pre-drilling/preforming and uplift tension
capacity. Furthermore, the benefits of embedded sensors include increased quality control/quality
assurance through 100% testing, accelerated construction, life cycle monitoring and asset management.
Citation
APA:
(2022) Role Advanced Technology - Resolve Inherent Dichotomy In High Strain Dynamic TestingMLA: Role Advanced Technology - Resolve Inherent Dichotomy In High Strain Dynamic Testing. Deep Foundations Institute, 2022.