Study of Pile Setup Evaluation Methods

Summary:

To expedite more rapid construction of bridges, it has been customary in many states to ignore setup effects when predicting pile group capacities. End of driving capacities have frequently been used as the design capacity for a pile group. For many soil profiles, setup yields pile groups that have significantly higher capacities after some amount of time when compared to the capacity immediately after driving. In order to meet the immediate capacity requirements, piles are often driven deeper than necessary in order to obtain some desired capacity at the time of pile driving, even though substantial increases in capacity may develop in the days and weeks following driving. Being able to perform in situ or laboratory tests that can predict the magnitude and/or rate of pile setup during the design stage would provide a much more efficient pile design, since the cost of materials and the construction time required to drive the piles would decrease. Piles could be driven to a lower capacity, knowing that after an anticipated amount of time the capacity would increase to the desired target capacity, and restrike analyses could be performed to verify this capacity. This study has investigated the side shear setup phenomenon and various methods of predicting the magnitude and/or rate of setup. This was done by means of conducting a literature review and a survey of transportation agencies. Several methods have been proposed for dealing with the setup phenomenon and these methods are described briefly in the body of this report.

Final Deliverables:

• Report #2009-38

Related Materials:

Related Research:

• Developing a Resistance Factor for Mn/DOT's Pile Driving Formula