Open-ended pipe piles (OEPPs) are often used to support a range of onshore and offshore civil infrastructure systems such as buildings and other structures that are vital to the economy of the United States. However, fundamental understanding of soil-pile interactions during the installation and operation of OEPPs remains limited. This limited understanding has led, in some cases, to disastrous consequences, such as foundation and structural failures and very significant economic losses. In this research, the response of OEPPs will be experimentally characterized and investigated during installation and under complex loading conditions. A series of installation and loading tests will be performed at Purdue University as well as at UniversitÃ© Grenoble Alpes by leveraging international collaborations. The broader impacts of this project are diverse and include developing educational tools on the solution of mathematical problems related to foundation engineering for undergraduate and graduate teaching, developing reliable design methods for OEPPs that can be used by the industry, increasing opportunities for partnerships between academia and industry, and paving the way for a strong and enduring international collaboration.
The objectives of the research are: (1) to develop a fundamental understanding of pile plugging processes during installation of OEPPs; (2) to develop effective methods to predict pile plugging during installation; and (3) to develop methods to account for the soil plugging history on the load response of OEPPs. These goals will be achieved through a comprehensive model pile testing program, using unique instrumentation schemes and advanced image analysis methods: Digital Image Correlation (DIC) and X-Ray Computed Tomography (CT). The experimental program consists of a series of tests involving varying sequences and combinations of installation processes (jacking and driving) and loading processes (axial and lateral, monotonic and cyclic loading) on model pipe piles. The parameters considered in the test plan are the pipe pile diameter, pile surface roughness, sand type, sand relative density and soil layering. The fundamental knowledge that will result from the project research will serve as the basis for the development of reliable methods to predict plug formation and pile installation resistance, as well as design methods for calculation of the resistances of OEPPs accounting for the pile plugging effect. The work is expected to significantly improve the safety and performance of onshore and offshore structures founded on OEPPs.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.