By: William G. Handlos, P.E. Research shows that GEOTERRA® and GEOTERRA® GTO structural mats provide a ground-surface reinforcement layer to support heavy loads over soft subgrades. More cost-effective than other reinforcement mat systems, the GEOTERRA mats can be used for temporary or permanent applications and are reusable. Offering high crush and flexural strength, the GEOTERRA mats have demonstrated the ability to handle the forces from some of the heaviest wheeled and tracked vehicles under severe conditions. Scope of Test: The University of Kansas Geotechnical Laboratory tested the performance of the GEOTERRA and GEOTERRA mat systems over weak to intermediate subgrades with CBR values ranging from 1% to 4%. They conducted a total of 12 tests to identify threshold and limit conditions, create a data-set for modeling, and determine the equivalent crushed aggregate base. Testing Procedure: Test sections were subjected to 40 kN (9 kip) cyclic loading on a 300 mm (12 in) diameter plate. Earth pressure cells were placed over of the subgrade to measure vertical interface stress distribution. Loading plate displacements were measured by the displacement transducer inside the actuator. Test Observations: The following conclusions were determined for the GEOTERRA and GEOTERRA GTO Structural Mat Systems: The GEOTERRA mats provide additional… Read more »