ABSTRACT
A sinkhole located within a municipal solid waste landfill in Missouri was proposed to be covered with a low-permeability composite landfill cap as part of the facility closure approved by the state regulatory agency. Concern over potential vertical settlement resulting from the load imposed by the cap prompted an evaluation of methods for structural support. Design concept options were evaluated and screened. Engineering analyses indicate that a reinforcing system incorporating a 2-layer geogrid will be adequate to protect the landfill cap from damage resulting from settlement. The resulting design was included in the overall landfill closure construction drawings; construction of the reinforcing system occurred in July, 1994. Field measurements to detect potential vertical subsidence at the sinkhole will be performed as part of the landfill post-closure program.
