Semester of Graduation

Fall

Degree

Master of Science in Civil Engineering (MSCE)

Department

Civil and Environmental Engineering

Document Type

Thesis

Abstract

The purpose of this research study is to evaluate the incorporation of pile setup into driven pile foundation designs in Louisiana. Pile setup is the time-dependent increase in bearing capacity of a driven pile. This phenomenon is widely recognized but is not widely incorporated into foundation designs. Setup primarily occurs in clayey soils which are abundant in Louisiana. After foundation piles are driven, their capacity can significantly increase over a period of time. An empirical formula developed to predict this increase in capacity was evaluated using pile load tests within Louisiana. The setup parameter β€œA” in the selected formula was back-calculated from the dataset to determine a setup parameter specific to Louisiana soil conditions. Pile capacities including the setup effect were predicted using the calibrated 𝐴 value and compared with the measured capacities. Using the results of this comparison, the statistics of the prediction model were obtained, and a reliability analysis using the First Order Reliability Method (FORM) was conducted to calibrate a resistance factor corresponding to the additional capacity due to setup for the strength limit state in a Load and Resistance Factor Design (LRFD) format. This calibrated resistance factor can be used in the design of driven piles to account for the additional increase in capacity that can be expected to occur due to setup. To demonstrate how the additional capacity due to setup will allow driven pile foundation to be more economical, a case study was conducted and concluded the number of required piles can be reduced by about 20% from a design using the pile capacity at 24 hours after driving. In addition, a survey was conducted to gauge the current state of practice and the perception practitioners held regarding setup. The survey was distributed to practitioners in the driven pile industry primarily in Louisiana and the Gulf Coast region.

Date

10-23-2018

Committee Chair

Okeil, Ayman

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