This Faculty Early Career Development (CAREER) award will explore the relationship between soil piping and rainfall-induced landslides in unsaturated soils. Piping occurs when flowing water erodes soil forming a conduit, or pipe, below the ground surface. Piping is one of the leading causes of failures of levees and dams, a major source of soil erosion worldwide, and can lead to the development of voids and sinkholes that may damage overlying infrastructure. The mechanics of piping remain poorly understood, hindering the development of methods to detect and monitor piping and methods to prevent failure or repair piping once it has begun. This project will develop a physics-based framework for assessing the development, progression, and consequences of soil piping through a multiscale program of experiments and numerical simulations. Improving the ability of engineers to detect and evaluate piping features will increase the resiliency of civil infrastructure to landslides and sinkholes, and help to reduce degradation of agricultural land and soil loss in hillslopes. This research will be integrated with an education and outreach program that seeks to increase interest and retention among traditionally underrepresented students in civil engineering. This will be accomplished through the creation of formal and informal educational activities, including educational modules for undergraduate and 7th-12th grade students and a citizen science-driven database of sinkholes and piping features. This project will also create a new course to train graduate students to effectively communicate their research to diverse audiences.

The process of soil piping involves complex hydro-mechanical interactions that occur across multiple length scales. Researchers in various disciplines have studied different aspects of soil piping, but there is a need for a convergent research approach to bridge the current knowledge gaps. This project will fill this need by identifying the hydro-mechanical properties and interactions that control subsurface erosion in unsaturated soils. X-ray micro-CT imaging will be used to understand how the soil microstructure influences erosion rates and large-scale experiments will be performed to examine pipe progression and collapse at the mesoscale. Non-destructive geophysical imaging will be integrated with measurements of suction, water pressure, and surface deformations to understand the interactions between the pipe and surrounding soil over time. These experiments will provide the data needed to develop and validate coupled hydro-mechanical simulations of soil piping and its influence on stability of slopes. The analysis framework developed in this study will be applicable to many other piping-related problems across a variety of disciplines.

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.

Project Start
Project End
Budget Start
2021-08-01
Budget End
2026-07-31
Support Year
Fiscal Year
2020
Total Cost
$531,818
Indirect Cost
Name
Auburn University
Department
Type
DUNS #
City
Auburn
State
AL
Country
United States
Zip Code
36832