NDOT US-385

Extremely weak soils (CBR < 0.5%) were encountered during construction of a highway embankment. Additionally, the subgrade soils consisted of saturated silty clay with a high water table, and the site was located a long distance from a high quality aggregate source. Designs consisting of 42"+ of imported material with multiple layers of geosynthetics and geogrids were proposed.

Tensar engineers used Tensar+ design software to produce a design consisting of 35" of clean sand placed over top of one layer of Tensar NX850™ geogrid. Using the on-site borrow material saved the customer from having to import aggregate from far off-site, and total savings numbered several millions of dollars.