Volume 32, N. 1, January-April 2009 | PDF(0 downloads)
This paper presents the results of a comprehensive experimental program for investigating the influence of mechanical damage on the load-displacement behavior of geogrids. Unconfined tension tests, pullout and direct shear tests were carried out on intact and damaged specimens. Natural or artificial damages were produced either by imposing heavy compaction procedures in the laboratory or by simply cutting one or more geogrid elements. It is concluded that natural damage in the geogrid may be more pronounced when aggressive compaction methods are used with coarse grained soils. Fine grained soils did not show a significant strength reduction even when subjected to heavy compaction in the laboratory. Under pullout loading, artificial damage was also noted to be of little significance for fine soil (silty clay). Rupture of the geogrid’s transverse elements led to a significant pullout strength reduction. These transverse elements are responsible for anchoring the geogrid within the soil mass. However, under unconfined tensile load, these transverse elements are responsible only for the grid’s geometrical configuration and their rupture did not induce a significant strength loss. In direct shear, the position of the geogrid relative to the potential failure surface was shown to be an important factor.