SYMPOSIA PAPER Published: 29 July 2019
STP161120170165

An Evaluation of High Pile Rebound in Glacial Till

Source

A test pile program was performed for the South Dakota Department of Transportation adjacent to a bridge construction project in eastern South Dakota that consisted of two 16-in. (406-mm) diameter closed-toe steel pipe piles and two HP 10 × 42 (HP 250 × 63) steel H-piles, each driven to differing depths. High-strain dynamic pile testing (HSDPT), along with an instrumented static loading test, were performed on each pile. During installation, the pipe piles unexpectedly experienced extreme “bouncing” behavior consistent with high-rebound conditions. These high-rebound conditions caused the piles to essentially “refuse” during initial driving. Restrike testing after a period of 7 days, however, showed that the piles could then advance with little difficulty. Reliance on driving formulas to determine pile capacity would have indicated an apparent loss of capacity due to the reduced penetration resistance during restrike; however, the HSDPT results showed the opposite, with increasing capacity with time even with the decrease in penetration resistance. These results were also confirmed by the results of the static loading tests. A seismic piezocone sounding test (CPTu) advanced at the site found very high penetration pore pressures within the glacial till soils that were causing the high-rebound driving conditions. A literature review indicated that other sites in the Southeastern United States exhibited high CPTu penetration pore pressures where similar high-rebound conditions occurred within the coastal and marine soils of that region. The data from this test pile program suggest that CPTu performed during the initial exploration and design phase can also aid in predicting high pile rebound conditions within glacial till soils of the Upper Midwest. The American Association of State Highway and Transportation Officials and many state department of transportation agencies have approved the use of pile-driving formulas for evaluating pile resistance; however, pile-driving formulas can overpredict pile resistance when driven into high pile rebound soils, and the data from this test site show that HSDPT can provide a more realistic capacity assessment in high-rebound conditions.

Author Information

Reuter, Gregory, R.
American Engineering Testing, Inc., St. Paul, MN, US
Price: $25.00
Contact Sales
Related
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Details
Developed by Committee: D18
Pages: 664–680
DOI: 10.1520/STP161120170165
ISBN-EB: 978-0-8031-7668-3
ISBN-13: 978-0-8031-7667-6