Concrete Stabilization Technologies, Inc. (CST) completed a high profile in-situ compaction and water control project at the Layland Canyon Phosphate Mine in western Wyoming. The Layland Canyon Mine area is an abandoned mountainside phosphate mine located in Lincoln County, near Cokeville, Wyoming. The mass grading and reconstruction of the slope area of the mine was being completed as part of the State of Wyoming’s reclamation of abandoned mine land. Concrete Stabilization Technologies, Inc. sub-contracted with Oftedal Construction, Inc. to perform the injection of Expanding Structural Polymer into areas of the high wall face area of the mine, in order to help steer water off the zone next to the face by compacting the soils and mitigating the settlement and water inflow into the backfill and rock interface. With topsoil being placed over this area, a desired shingle effect was created beneath to divert water, and help stabilize and control future erosion of the reconstructed area.
Concrete Stabilization Technologies, Inc. Regional Engineer Roy Mathis worked with Chris Walla, P.E., of RESPEC Consulting to develop the procedure and specification for injection of Expanding Structural Polymer (ESP) that was successfully used on this project. Crews joined Oftedal Construction, Inc. for a site-specific safety meeting, and then drove to the injection location to begin placing probes and prepping the CST injection equipment. After a field adjustment by AVI’s Field Engineer the first set of injections were placed on the north end of the high wall, 11 feet south of Station 17+70, 59 feet north of the original plan. Due to wider top bench, injection points were moved 30 to 40 feet north of the original injection plan. ESP design was adjusted from three injection rows, to two rows. The second row was adjusted with increased material per injection location in order to ensure good compaction and the material spread between injections into the backfill and against the high wall. Injections were made at three foot and 10 foot depths.
CST crews were highly efficient in completing the project and devising the best solution based on actual field conditions once the work began. In consideration of water runoff, adjustments were made to meet the goal of shedding water away from the high wall. Slope changes were taken into account and injection points altered from the original 2 foot area to 4 foot along the slope and wall in order to provide maximum effect from the stabilization of the soil. Adjustments to compensate for blowout were also made at the 10 foot level.
The CST ESP was injected into the high wall area of the mine site, successfully compacting, stabilizing and providing erosion protection for the abandoned area. Even as inclement weather rolled in, the work was completed in three days. A total of 1100 lineal feet of compaction and water control was completed at the interface of the high wall and fill material to assure stabilization of the soils and provide excellent results for the successfully reclaimed mining site.