The U.S. Department of Transportation and the Atchison, Topeka, and Santa Fe Railway Co. (ATSF) are jointly sponsoring a railroad test embankment on the main line of the ATSF system. The test embankment is nearly 2 miles long and is comprised of a minimum thickness of 6 ft of compacted, highly plastic clay. The embankment is divided into nine test sections, each with a unique track support system but having identical embankment instrumentation.
This paper discusses the considerations leading to final design, fabrication, and installation of the embankment instrumentation. The embankment instrumentation was developed to provide quantitative data on embankment performance and response to aid in the comparative evaluation of track structure performance. Emphasis was placed on reliable measurements of dynamic embankment strain. Provisions for measurement of long-term deformations and volume changes in the highly plastic clay embankment were also provided. Each of the nine test sections has one principal instrument array supplemented by additional instruments spaced to verify that the performance at the main arrays is typical for that test section. The main array instrumentation includes vertical extensometers, portable horizontal extensometers which will be inserted in flexible horizontal tubing embedded in the embankment, pressure cells, and moisture-temperature cells. The instrumentation was specifically designed for this project.