MG 221 - REINFORCED EARTH AND GEOTEXTILES

Faculty: Samirsinh .P.ParmarDepartment of Civil EngineeringFaculty of Technology, Dharmasinh Desai University,NadiadMail Add: samirddu@gmail.com

REINFORCED EARTH Basic introduction to the elements of ground

engineering characteristics of reinforcing materials, definition of reinforced and advantage of RE, Soil reinforcement interaction.

Behavior of reinforced earth walls, basis of wall design, the coulomb force method, the Rankin force method, internal and external stability condition, field application of RE.

Randomly reinforced earth and analysis of reinforced soils, testing of soil reinforcements.

GEOTEXTILES Definitions, functions, properties and

application of geotextiles, design of geotextile applications.

Definitions, functions, properties and application of geo membranes, design of geo membranes applications, geo textiles associated with geo membranes.

Testing on geo textiles, environmental efforts, ageing and weathering.

ROUGH IDEA !

HISTORY

CONCEPT OF REINFORCED EARTH ??? Soils which have little if any tensile strength can

also be strengthened by the inclusion of materials with high tensile strength.

This mobilisation of tensile strength is obtained by surface interaction between the soil and the reinforcement through friction and adhesion.

The reinforced soil is obtained by placing extensible or inextensible materials such as metallic strips or polymeric reinforcement within the soil to obtain the requisite properties.

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HISTORY This kind of principle is also used in building parts

of Great Wall of China and the Babylonian ziggurats i.e. temples.

Textile material was perhaps first used in road construction in South Carolina in the early 1930s.

The first use of woven synthetic fabrics for erosion control was made in 1958 by Barrett.

WHY SOIL REINFORCED?? Improves soil bearing capacity, reduce

settlement. Reduce liquefaction behaviour of soil. Improves Mechanical Properties of soil. More economical then conventional methods.

MECHANISM OF REINFORCED EARTH Soils which have little if any tensile strength

can also be strengthened by the inclusion of materials with high tensile strength.

This mobilisation of tensile strength is obtained by surface interaction between the soil and the reinforcement through friction and adhesion.

The reinforced soil is obtained by placing extensible or inextensible materials such as metallic strips or polymeric reinforcement within the soil to obtain the requisite properties.

MECHANISM OF REINFORCED EARTH Soil reinforcement through metallic strips,

grids or meshes and polymeric strips sheets is now a well developed and widely accepted technique of earth improvement.

Anchoring and soil nailing is also adopted to improve the soil properties.

TYPES OF GEO-MATERIALS (GEOSYNTHETICS FAMILY)1. Geotextile.2. Geogrid.3. Geonet.4. Geo Membrane5. GeoComposites6. Geofoam7. Geocell8. Geomat9. Geomesh10. Geopipe11. Geospacer

1. GEOTEXTILE

Woven

Knitted

Non Woven

2.GEO GRID

(i) Uniaxial (ii) Biaxial

(iii) Bonded (iv) Woven

3. GEONET.

4. GEO MEMBRANE

5. GEOCOMPOSITES

Combination of one or more type of geosynthtics for modified function.

6.GEOFOAM

Foam like material, provided for functions mentioned below:

Moisture retention. Erosion protection. Generally gives temporary solution of the

problem.

7.GEOCELL

GEO CELL(a) Geocell – (i) site assembled, (ii) factory produced (A) collapsed form, (B) expanded form

8.GEOMAT

9.GEOMESH

10.GEOPIPE

11.GEOSPACER

TYPES OF GEOSYNTHETICS & THEIR SYMBOLS

POLYMERS COMMONLY USED FOR THE MANUFACTURE OF GEOSYNTHETICS

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