The South Dakota Department of Highways has attempted to correct landslide problems on I90 by constructing a stable fill over a descending draw. The area is composed of what is called "Pierre shale" which has a high liquid content and easily loses strengh because of the amount of moisture in the faults and joints. Corrective measures taken were: 1) the evaluation of roadbed grade was lowered five feet; 2) subsurface drains were installed; 3) alluvial soil was removed down to watertight soil; 4) surface drainage pipes were installed in the bottom of each side draw; 5) subdrain pipe and porous granular material was installed to remove see page water; 6) embankment slopes were flattened and extended; 7) surface of the berms and fill-slopes were protected by contour drainage dikes and ditches; and 8) application of a watertight asphalt membrane to control entrance of surface water. At the present time it appears that the landslide problem has been solved by the corrections, but only time will tell, and a research study is slated for 1976-1978 to evaluate the performance of these methods.

  • Corporate Authors:

    Scranton Publishing Company

    434 South Wabash Avenue
    Chicago, IL  United States  60605
  • Authors:
    • Potter, A
  • Publication Date: 1976-5

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Filing Info

  • Accession Number: 00141300
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Oct 26 1976 12:00AM