STUDY OF THE MECHANICAL PROPERTIES OF A HEXAGONAL GEOGRID USING THE DIGITAL IMAGE CORRELATION METHOD

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7105-99-5 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 12, 809-816 pp, DOI: 10.5593/sgem2017/12/S02.103

ABSTRACT

One of the common applications of geosynthetics is their use as reinforcement for aggregate and soil layers. Geosynthetics improve the mechanical properties of the reinforced layers, which are originally, due to various reasons, insufficiently protected. Therefore, the use of geosynthetics allows for bearing heavier loads thanks to the soil-reinforcement system and an extended material durability.
This article describes the laboratory tests of mechanical properties of a hexagonal geogrid made of polypropylene used for the reinforcement of soil and aggregate layers. The tests made use of a modern non-contact method for measuring the deformation of the specimen in the direct tensile test. The digital image correlation (DIC) method was implemented. Based on the conducted tests and numerical evaluation of the results, mechanical parameters for the hexagonal grid were determined with particular emphasis on the stiffness of the nodes. One of the conclusions emerging from the tests and analyses is the finding that the DIC method allows for the determination of displacements and strains of geosynthetic samples at any point and in any direction with the solution of the issue of principal values and principal directions. It is unattainable by means of traditional measurement methods using a strain gauge technique.

Keywords: geosynthetics, hexagonal geogrid, digital image correlation, strength tests, wide-width tensile test