Intelligent Soil Compaction Systems

Project Details
STATUS

Completed

START DATE

07/01/06

END DATE

10/31/10

RESEARCH CENTERS InTrans, CEER, CTRE
SPONSORS

Ammann Construction Equipment
Bomag Americas, Inc.
Case Construction Equipment
Caterpillar
Dynapac
National Cooperative Highway Research Program 21-09
Sakai Heavy Industries Ltd.
State DOT Partners: MN, NC, FL, MD, CO
Transportation Research Board
Trimble Navigation

Researchers
Principal Investigator
Michael Mooney
Co-Principal Investigator
David White

Geotechnical Engineer

Student Researcher(s)
Robert Rinehart
Normal Facas
Mark Thompson
Pavana Vennapusa
Odon Musimbi

About the research

The NCHRP Project 21-09, “Intelligent Soil Compaction Systems,” was undertaken to investigate intelligent soil compaction (IC) systems and to develop generic specifications for the application of IC in quality assurance (QA) of soil and aggregate base material compaction. The term intelligent soil compaction systems was defined to include (1) continuous assessment of mechanistic soil properties (e.g., stiffness, modulus) through roller vibration monitoring; (2) automatic feedback control of vibration amplitude and frequency; and (3) an integrated global positioning system to provide a complete geographic information system-based record of the earthwork site. An equally important term is roller-integrated continuous compaction control—defined by IC components (1) and (3).

Roller-integrated continuous compaction control (CCC) technology was initiated in Europe in the 1970s and has been used in European practice for nearly 20 years. The first European specification for roller integrated CCC was developed in Austria in 1990. Today, four European countries have soil compaction QA specifications using roller-integrated CCC (Austria, Germany, Sweden, and Switzerland) and U.S. states are beginning to implement pilot specifications (e.g., Minnesota). In European specifications the use of automatic feedback control IC rollers is permitted during compaction but not during QA because the roller measurement values (MVs) can be strongly influenced by varying amplitude and frequency. The dependence of roller MVs on frequency and amplitude in particular was verified in this study and further determined to be quite complex and difficult to predict. Accordingly, the recommended specifications developed here allow IC during compaction but do not permit the use of automatic feedback control IC during roller-based QA.

The following are the key items covered in this project:

Recommended Specifications for Roller Integrated CCC in Earthwork QA

Fundamentals of Roller Measurement Systems

Relationship Between Roller-Measured Stiffness and In Situ Stress-Strain-Modulus Behavior

Evaluation of Automatic Feedback Control-Based Intelligent Compaction

Correlation of Roller Measurement Values to Spot-Test Measurements

Case Study Implementations of Recommended Specifications

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