Volume 35, N. 1

January-April 2012

Evaluation of Direct Shear Tests on Geogrid Reinforced Soil

Article

Volume 35, N. 1, January-April 2012 | DOWNLOAD PDF (16 downloads)

Abstract

This paper presents a program of direct shear tests in soil reinforced with geogrids, carried out with large-scale equipment. A woven geogrid was placed in sandy soil and positioned with different inclinations inside the shear box. The strength parameters of the soil-geogrid interface were obtained from shear tests with the geogrid positioned horizontally in the sand. The direct shear tests with inclined reinforcement revealed the strength differences related to the reinforcement inclination, seeking to define the most favorable positioning of the geogrid for construction works in reinforced slopes. An analysis of the deformed configuration of the geogrid is presented, based on the measured position of the grid at the end of the shear tests. Finally, numerical simulations of the direct shear tests were carried out, allowing an assessment of the tensile forces acting on the inclined reinforcement. These studies allowed a clear definition of the soil region that is not distorted during the direct shear test, being subject to a simple translation only. The geogrid’s displacements were found to be anti-symmetrical in relation to the failure plane. Shearing was concentrated at the central region of the specimen’s height, with the upper and lower regions being simply subjected to translation, with no distortion. The inclination of the reinforcement within the soil has a significant influence, with the maximum strength occurring when the geogrid was positioned at 60° angle in relation to the failure plane.

Keywords: Reinforced soil, Geogrids, Direct shear tests, Numerical analyses,


Submitted on December 02, 2010.
Final Acceptance on April 03, 2012.
Discussion open until September 30, 2012.
DOI: 10.28927/SR.351065