DFI Announces Winners of 2019 Student Paper Competition 

November 7, 2019, Hawthorne N.J.:

Abigail H. Bateman and Jamie J. Crispin, from the University of Bristol, Bristol, U.K., are the 2019 Student Paper Competition winners. Their winning paper, “Theoretical “t-z” Curves for Piles in Radially Inhomogeneous Soil,” described the development and evaluated the use of a radial inhomogeneity correction factor for selected constitutive models. 

The paper considers the installation of a pile foundation, which results in a radially variable shear modulus distribution in the surrounding soil. For a simplified framework, theoretical “t-z” curves can be derived by substituting an attenuation function, which describes the variation of shear stress with distance from the pile, into a soil constitutive model, which relates shear strain to shear stress. The settlement at the pile circumference due to an applied shear stress can be determined by integrating expressions in the constitutive model with respect to distance. Only a limited amount of analytical “t-z” curves are available in the literature (e.g., linear-elastic, power-law and hyperbolic constitutive models), which use a concentric cylinder model to define an attenuation function. However, radially homogeneous soil is usually assumed, which ignores the effects of pile installation resulting in unconservative calculations of pile settlement. 

DFI and the DFI Educational Trust annually hold the Student Paper Competition as a means to bridge the gap among practice, studies and research. 

The award was presented at the DFI 44th Annual Conference on Deep Foundations, October 15-19, in Chicago, where Bateman and Crispin were invited to present the winning paper to conference attendees. The winning paper will be published in a future issue of the DFI Journal. The award recipients also received a library of up to 20 printed DFI publications and a gratis two-year DFI Individual Membership.

Contact: Emilio S. Fandino, Trust Administrator, (973) 423-4030,

About DFI Educational Trust: The Deep Foundations Institute Educational Trust ( is an independent, 501 (c) (3) nonprofit organization established in 2006 by the Deep Foundations Institute (DFI) as its charitable arm. The mission of the Trust is to support and encourage individuals in the fields of study related to the deep foundation industry by providing scholarships and opportunities to meet and work with deep foundation industry leaders.

About Deep Foundations Institute (DFI)
DFI ( is an international association of contractors, engineers, manufacturers, suppliers, academics and owners in the deep foundations industry. Our multidisciplinary membership creates a consensus voice and a common vision for continual improvement in the planning, design and construction of deep foundations and excavations. We bring together members for networking, education, communication and collaboration. With our members, we promote the advancement of the deep foundations industry through technical committees, educational programs and conferences, publications, research, government relations and outreach. DFI has more than 3,500 members worldwide.

Student Paper Winners: Jamie Crispin and Abigail Bateman with Tracy Brettmann (center), chair of the DFI Educational Trust