Beaver Creek/ Twin Creek/ Sawdust Slide- M.P. 55.1 Highway 28

Construction of Sawdust Fill

 

The Beaver Creek area has been actively moving for several years. In 1971, movement was detected above the highway but was not interfering with the highway at that time. During a 1982 geotechnical investigation for a proposed highway realignment, the potential slide area was mapped more accurately. The proposed realignment construction began in 1985, however the Beaver Creek slide failed during construction, forcing a quick fix. The area was stabilized using a toe berm constructed of dirt and large boulders. Unfortunately, movement at the site continued through 1986, prompting WYDOT to find another solution.
It was decided to use lightweight fill and a drainage gallery to stabilize the slide area. The lightweight fill, or sawdust, was readily available at the time from a local saw mill. Construction was completed in 1988. Highway 28 showed only minimal problems for the next 10 years. However,  pavement cracks did develop, compelling WYDOT to perform another geotechnical investigation.
Several inclinometers were installed over the next several years which provided slide depths and limits. Ground Penetrating Radar (GPR) was also employed, as were water monitoring wells, to further aid in the investigation. It was determined that the sawdust fill from the 1988 construction was saturated and deteriorating. A lightweight fill replacement was needed but all local sawmills had closed. It was decided to use tire bales. The tires were available to WYDOT from a contractor in Gillette Wyoming (approximately 350 miles away). Through a special program the tires and the delivery of the tire bales were offered to WYDOT at no cost. The tire bales were 2.5’ (h) x 4.0’ (w) x 5.5’ (l) or approximately 2 C.Y. and weighed approximately 2000 lbs. The sawdust from the 1988 construction was removed from the site and replaced with the tire bales. The tire bales were stacked like blocks and then wrapped with a non-woven geotextile. Construction began in the spring of 2008 and was completed in the summer / early fall of 2008.  Below is a sequential view during construction of the Beaver Creek Slide area.



Construction finished!!