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Research and Development (R&D) Project Sites

Project Information
Project ID:   FHWA-PROJ-07-0025
Project Name:   Development of Soil Stiffness Measuring Device for Pad Foot Roller Compaction
Project Status:   Completed
Start Date:  September 27, 2007
End Date:  December 30, 2010
Contact Information
Last Name:  Adams
First Name:  Michael
Telephone:  202-493-3025
E-mail:  mike.adams@dot.gov
Office:   Office of Infrastructure Research and Development
Team:   Bridge and Foundation Engineering Team [HRDI-40]
Program:   Exploratory Advanced Research
Project detail
Project Description:   This project proposes to develop and test a "smart pad" for pad foot roller compactors, which is very different from vibratory compaction systems. This project will integrate static soil stiffness measurement capabilities with wireless communications and the global positioning system for continuous real-time feedback on soil stiffness for fine-grained and mixed soil types.
Goals:   Improve construction practices through new technology.
Background Information:   This project is a response to an Exploratory Advanced Research Program broad agency announcement in the highway infrastructure focus area.
Related URL(s):   http://wwwcf.fhwa.dot.gov/exit.cfm?link=http://smartgeo.mines.edu/upload/poster_soil.pdf
Project Findings:   Measurement of soil stiffness during compaction of foundations for highway structures is critical to ensuring that design-life specifications are met. In this study, investigators developed a conceptual framework for determining pad–soil contact force and displacement (and thus soil stiffness) from sensors built into the pads and roller, constructed a prototype measurement system, and devised a wireless data acquisition system to enable field-scale testing. They successfully measured plastic and elastic soil deformation during compaction using laser-based distance sensors and pad-strain-based techniques. Laboratory and field testing confirmed the predicted strain field changes. Some elements of the model need further refinement to ensure repeatable and accurate measurement across various soil conditions.
FHWA Topics:   Research/Technologies--FHWA Research and Technology
TRT Terms:   Construction and Maintenance
Wireless Communications Systems
Global Positioning System
FHWA Disciplines:   Geotechnical
Pavement and Materials
Subject Areas:   Geotechnology


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