The total landslide repair project consists of: approximately 450 Cubic Yards of excavation; approximately 350 Cubic Yards of excavation haul off; construction of an approximate 305 Cubic Yard Class I Random Rip Rap Shear Buttress, including subgrade preparation and geotextile installation (estimated 690 Cubic Yards of geotextile installation to encompass shear buttress and wrap drain rock); placement of low permeability Select Granular Fill or Mud Mat to achieve required embedment into bedrock and drainage grades for the bottom of the shear buttress; construction of shear buttress subdrainage, including installation of approximately 40 Lineal Feet of 6-in diameter solid pipe and 105 Lineal Feet of 6-in diameter perforated pipe, with drain rock/pipe bedding material wrapped in geotextile; placement of approximately 110 Cubic Yards of Engineered Fill capping material; placement of approximately 55 Cubic Yards of topsoil, regrading, and seeding with Montana Fish, Wildlife, and Parks (FWP) approved Northern Dryland Seeding Mix for approximate 485 Square Yard repair area; and construction of approximately 85 Square Yards of grouted rip rap drainage chute and grouted rip rap settling basin.
