In late fall of 2005, the Zachry Construction Corporation contracted with TXI to position 24,000 cubic yards of 3/8 x #10 of ES&C on the south end of the iconic Pennybacker (or 360) bridge embankment, while the north end received regular fill dirt or limestone screenings. Not surprisingly, in June of 2006, experts from the University of Texas-Arlington's Engineering Department, under the direction of the Texas Department of Transportation's Fort Worth office, installed inclinometers to measure the amount of settlement on both the north and south ends of the bridge. After 9 months, the north end of the embankment (regular fill) had settled approximately 1.5 inches while the south end of the embankment (expanded shale) has remained settlement free.
In this photo of the finished bridge, the view is from south to north. The embankment that contains the expanded shale is on the left.
The vertical inclinometer data is also available.
