• Use of Geogrids for Limiting Longitudinal Cracking in Roads on Permafrost

      Savage, Bonnie Mae (1991-05)
      Longitudinal cracking of road embankments results from lateral movement of the subbase which creates a subsurface void space. The void spaces propogate to the surface causing cracks and voids. This is hazardous to motorists and expensive to repair. This thesis examines the use of geogrids to limit lateral spreading thereby preserving safe and useable road surfaces. A field experiment, a full-scale laboratory experiment, a soil arching experiment, and behavioral and theoretical analyses are presented. Soil arching forces are quantified and developed using an experiment based on work done by Terzaghi and Kienzl. A theoretical analysis for quantifying the shear force redistribution to be used for geosynthetic embankment systems, was derived from the Soil Arching Experiment. Relationships of load, embankment resistance, deflection and geometric factors are presented. A comparison of geogrid performance to a geotextile performance for the given relationship is presented as well.