Evaluation of Interaction Properties of Geosynthetics in Cohesive Soils: Lab and Field Pullout Tests;Final rept. Jul 97-Dec 03

摘要

The considerable increase of using geosynthetics in mechanically stabilized earth (MSE) walls has raised the need to evaluate their interface shear strength and pullout properties in various types of backfills. This report investigates the use of a marginal silty-clay soil of medium plasticity as a suitable backfill in MSE walls. The interface parameters between the geosynthetics and the soil were evaluated in pullout tests. The testing program included performing laboratory and field pullout tests on four types of geogrids and three types of geotextiles. Laboratory pullout tests were carried out using the large pullout testing equipment at the Louisiana Transportation Research Center (LTRC). Field pullout tests were performed in a test section of the LTRC full-scale reinforced test wall. The pullout test section contained geogrid and geotextile specimens at various wall elevations. The testing program evaluated the effect of reinforcement type, length, and confining pressure on the pullout resistance. Laboratory and field tests were performed using the same type of soil at a similar density and moisture content. Laboratory and field results compared well for the extensible reinforcements of medium to low stiffness modulus.