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.

Evaluation of Geogrid in Unpaved Road Constructed on Sand Subgrade under Cyclic Loading

“…6 shows the effect of position of one geogrid reinforcement layer on the relation between the rut depth and the number of load cycles, test series II. The results concluded that the optimum position of one geogrid reinforcement layer is at the upper quarter of the base course layer and not at the interface as previously showed by Barksdale et al, (1989), Chan et al, (1989), Degroot (1986), McGown and Andrawes (1977) and Rowshanzamir and Karimian (2016).…”

Evaluation of creep behavior of high density polyethylene and polyethylene-terephthalate geogrids

“…The onset of the secondary creep stage is detected at approximately 10% of creep strain. It should note that the 10% of creep strain has been reported as ''performance limit strain'' for the HDPE geogrid by Den-Hoedt (1986), Ingold et al (1994) and McGown et al (1995). The onset of tertiary creep stage is observed at approximately 60% of creep strain, which then leads to creep rupture.…”

The role of geosynthetic stiffness in soil reinforcement applications

“…The earliest attempt to characterize the load-strain time behaviour of extensible geosynthetic sheet reinforcement products under constant tensile load can be traced to the seminal work of McGown et al [1,2]. They introduced the concept of isochronous load-strain curves.…”