CAREER: Advanced and Uncertainty-Informed Site Investigation

Portland State University, Portland OR

Investigators

Abstract

Research funded by this Faculty Early Career Development (CAREER) award plans to advance the capability of geotechnical site investigation by exploring fundamental soil relationships and the uncertainty associated with subsurface data interpretation. Geotechnical site investigation is critical to safe, cost-efficient, and resilient civil infrastructure. However, it remains a challenge for civil engineering practice. Insufficient site investigation is a primary reason for project budget and timeline overruns or insurance claims on construction projects. The cone penetration test collects subsurface data and is used throughout geotechnical and environmental engineering practice. Engineers use cone penetration test data cautiously when soils and conditions vary from the standard soils that data interpretation methods were developed and validated with. Findings from this research are intended to provide engineers with a more capable framework for site investigation by (1) estimating advanced engineering parameters from cone penetration test data for standard and non-standard soil types, therefore allowing engineers to do more with the data, and (2) quantifying uncertainties associated with site investigation data for both standard and non-standard soils, therefore enabling engineers to propagate uncertainties to predicted performance of infrastructure, and evaluate the value of additional data. This project integrates research with an education and outreach program for community college transfer students that aims to increase the number of students who successfully transfer to and graduate from four-year Civil Engineering programs. The project will support outreach events at local community colleges, organization of an annual transfer student workshop, including research lab tours and outreach demonstrations, and hosting undergraduate community college transfer students in research intern positions. This research will advance site investigation methods by examining fundamental soil-load interactions during cone penetration testing and characterizing uncertainties stemming from soil parameter estimation. The objectives of this research are to (i) investigate relationships between soil type, soil properties, initial conditions, critical state line position and shape, and cone penetration test data, (ii) investigate uncertainty quantification for cone penetration test-based soil parameter interpretation in standard and non-standard soils, and (iii) explore uncertainty quantification and data assimilation in the broader context of site investigation. An integrated program of advanced laboratory testing, a system-level computational cone penetration model, and physical cone penetration tests will characterize the fundamental role of the soil critical state line and initial state on cone penetration test data. The anticipated outcome of this investigation is a critical state line-based interpretation approach for cone penetration test data that will be developed and validated across a range of standard and non-standard soils. A large dataset of soil properties and site investigation information will be used to investigate uncertainty associated with soil parameter estimation from site investigation data. This assessment will enable a framework for uncertainty-informed site investigation that will propagate uncertainties from site tests to design and predicted performance, enabling engineers to use quantifiable metrics for site investigation decisions alongside their engineering judgment. 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.