Strain Behaviour of Polymeric Geogrids Subjected to Sustained and Repeated Loading in Air and in Soil

Abstract

The stress transfer mechanism in uniaxially and biaxially stretched polymeric geogrids are largely dependent on the interlocking mechanism between the soil and reinforcement. Over the years, this mechanism which may be termed the static interlock mechanism, has been researched and gained wide recognition. When pre-stretched polymeric geogrids are subjected to repeated loading cycles such as compaction forces, a second mechanism which may be termed the dynamic interlock mechanism is developed. In this paper, the existence of this mechanism is established through a series of in-air and in-soil static and dynamic tensile load tests using uniaxially pre-stretched HDPE geogrid specimens. The series of tests also identifies the importance of proper positioning of strain measuring instruments along reinforcements used in reinforced soil structures.