Geogrids are open polymer structures formed by bonding polymer strips at cross points. They are commonly made of materials like polyester, polyvinyl alcohol, and polypropylene. The major function of geogrids is to reinforce soils and resist tensile forces. The first geogrids were invented in the UK in 1982 and brought to North America by Tensar Corporation. Geogrids are now used to reinforce road bases, retaining walls, bridges, and reinforced soil slopes due to their ability to increase construction speed and provide proper reinforcement at a lower cost.

1. GEOGRID AS A SOIL
REINFORCEMENT
 PRESENTED BY :
 - PRATYUSHA
 BANDYOPADHYAY
 CIVIL-204
 CALCUTTA INSTITUTE
OF ENGINEERING AND MANAGEMENT
 GUIDED BY :
 - SSI SIR

2. INTRODUCTION
Geogrids are nothing but
the open structures
formed by bonding
polymer strips at their
cross point. Commonly
made of polymer
materials, the major
function of the
geogrids is in the area
of reinforcement to
resist the tensile force.

3. HISTORICAL EVOLUTION
 The first and original geogrids ( called unitized or
homogeneous types) were invented by Dr. Frank Brian
Mercer in the United Kingdom at Nelton Ltd. and were
brought in 1982 to North America by the Tensar
Corporation.
 The second category of geogrids are more flexible geogrids
using bundles of polyethylene-coated polyester fibres were
first developed by ICI Linear Composites LTD. in the United
Kingdom around 1980.
 The third category of geogrids are made by laser or
ultrasonically bonding together polyester or polypropylene
rods in a grid like pattern.

4. OF ROADWAY BASES
GEOGRIDS USED AS REINFORCEMENT

5. TYPES OF GEOGRID
WOVEN NONWOVEN
MICRO ONE-WAY BIAXIAL MULTI LAYERED
WELDED-STRIP

6. TYPES OF GEOGRIDS

7. COMPOSITION
 1. POLYESTER
 2. POLY VINYL ALCHOHOL
 3. POLY VINYL CHLORIDE
 4. POLY PROPYLENE

8. INSTALLATION GUIDELINES
 1. MATERIAL IDENTIFICATION
 2. MATERIAL HANDLING
 3. GEOGRID PLACEMENT
 4. PLACEMENT OF FILLING
MATERIAL

9. APPLICATIONS OF GEOGRIDS
 1. RETAINING WALLS
 2. BRIDGE/ RAILWAY ABUTMENTS
 3. REINFORCED SOIL SLOPES
 4. REINFORCED FOUNDATIONS OVER
PILES
 5. REINFORCED EMBANKMENTS
OVER SOFT FOUNDATIONS

10. GEOGRID REINFORCEMENT

11. ADVANTAGES
 1. It is cost saving material.
 2. It increases construction
speed.
 3. Proper reinforcement is
achieved.
 4. Improved quality.

12. REFERENCES
 1. http://en.wikipedia.org/wiki/Geogrid
 2. Müller, W. W.; Saathoff, F. (2015).
"Geosynthetics in geoenvironmental
engineering". Science and Technology of
Advanced Materials 16 (3):
034605. doi:10.1088/1468-
6996/16/3/034605. edit
 3. Ward, I. M. (1984) “The Orientation of
Polymers to Produce High Performance
Materials” Proceedings of the Symposium on
Polymer Grid Reinforcement in Civil
Engineering,Institution of Civil Engineers, UK.

13. THANK YOU