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421 E. El Segundo Blvd
El Segundo, CA
Tel: +1 310 322 1920
        +1 310 322 1922
Fax: +1 310 322 5146

In 1969, Foundation Mechanics, Inc. was incorporated in the state of California as a subsidiary of Wyle Laboratories. Wyle Laboratories had been a leader in testing and in the design of testing systems for the aerospace and nuclear industry for nearly fifty years. Foundation Mechanics, Inc. (FMI) is now privately held and operates from its world headquarters near the Los Angeles airport in El Segundo, California. FMI has been designing and building dynamic pavement testing systems since its inception. The Road Rater™ was built in 1970, followed by the Pavement Profiler in 1972, and then the JILS-FWD in 1987.
Today, FMI, now known and marketed as JILS, produces dynamic custom-designed pavement and foundation loading and testing systems for state, county, and city departments, private agencies, medical and aerospace applications, and numerous other entities world-wide. All JILS systems are well supported and have earned a strong reputation for performance, accuracy and reliability.
A falling weight deflectometer, or FWD for short, is a testing device used by civil engineers to evaluate the physical properties of a stretch of pavement. This could include (but is not limited to) highways, local roads, and airport runways. The machine is usually contained within a trailer that is driven to a location by another vehicle. At a pre-designated change in distance, the FWD device is deployed. A metal plate on the device is set up to strike the pavement at a given force, and sensors are placed around the plate and in a straight line radiating from the plate. These sensors record the deflections in the pavement (analogous to ripples in a pond) induced by the falling weight, hence the name "falling weight deflectometer".

This device has several practical purposes in determining the properties of pavement. For one, voids or empty spaces can be detected underneath the roadway. Joint testing determines how two abutting slabs of concrete or asphalt are fitting against one another. Other statical analyses determine the general strength of the structure, and can even predict what materials and in what combination were used to build the pavement if such information is unknown.