Integrity and Load Testing Auger Cast-in-Place (ACIP) Piles : A Combined Approach Using Thermal Integrity Profiling (TIP) and Dynamic Load Testing-PPT Presentation

PPT Presentation

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The presentation describes combining Dynamic Load Testing (DLT), a load transducer, and Thermal Integrity Profiling (TIP) to assess auger cast-in-place (ACIP) piles. ACIP piles are quick to install and produce little noise or vibration, but their as-built shape, concrete properties, integrity, and load performance can be uncertain.<br /><br />DLT can estimate pile capacity, stresses, and potential integrity issues, but testing cast-in-place piles is complicated by variable geometry and material stiffness. A steel load transducer provides a known cross-section and material properties for strain gauges, improving force measurements and reducing dependence on concrete quality and pile-head preparation. TIP uses heat from cement hydration to assess the pile along its length, helping identify shaft dimensions, cage alignment, and potential defects. With suitable casting records, it can also support estimates of the as-built pile profile.<br /><br />A Melbourne case study tested 25 ACIP piles, with three comparison piles assessed using both conventional pile-head gauges and a load transducer. TIP data helped inform the pile model used in CAPWAP analysis, but interpretations were affected by an assumption that the steel liner at the pile head was unbonded to the concrete. Treating the liner as bonded and using composite section properties produced a better match to measured data. The load transducer initially read about 10% higher than pile-head measurements; investigation indicated that the conventional analysis had used an incorrect wave speed. Revising the assumed pile modulus brought the results into agreement.<br /><br />The presentation concludes that TIP and load transducers reduce uncertainty and improve pile modelling and capacity analysis. Engineers should carefully assess liner bonding and wave-speed assumptions, since incorrect assumptions can distort the inferred pile profile and capacity distribution.

Keywords

Dynamic Load Testing

DLT

Thermal Integrity Profiling

TIP

auger cast-in-place piles

ACIP piles

load transducer

pile capacity analysis

CAPWAP

pile integrity assessment