Geo-synthetics and Reinforced Structures Semester 8 (BE Fourth Year) BE Civil Engineering University of Mumbai Topics and Syllabus

• Definition of geosynthetics.
• The terminology includes natural fibre materials such as coir, jute and hemp.

• Different types of geosynthetics (nonwoven and woven geotextiles, geogrids, geonets etc) and their exclusive functions and applications.

• Polymersfor geotextiles- Basis of polymers and resins, classification and types, brief manufacturing (PP/PE/PET (Polyester)/PA (Nylon) etc.),
• property comparison (physical, mechanical and weatherability etc.) and applications, influence of UV rays and stabilization.
• a. Environmental implications of use of these materials, recyclability and life cycle analysis.

• Geosynthetic types: Geotextiles, geogrids (knitted, woven, extruded), geonets, geomembranes, geosynthetics clay liners, geopipe, geofoam, geocomposites and geocells.
• Filter type, yarn types and mechanical properties:Manmade and natural (jute/coir), monofilament, multifilament, staple fiber yarn, flat tape yarn and fibrillated tape yarn, stress-strain curves and linear density of yarns.
• Geotextile types and their mechanical and functional properties: woven fabrics, nonwoven fabrics- staple fibre, spun bonded, thermal bonded; knitted and braided fabrics, functional properties of different fabrics.

• Various international bodies that have come up with testing codes,
• standards and guidelines (BIS, ASTM, ISO, etc.).
• What is followed in India and why?

A brief on testing techniques(index and performance tests) for each of the following parameters and their application based significances:

a.Basic physical properties including (but not limited to):

1. Constituents of the material
2. Unit weight
3. Thickness, etc.
4. Apparent Opening Size

b. Mechanical properties including

1. Various strength characteristics, including significance of peak strengths, residual strengths as applicable
2. Elongations at break for tensile strengths
3. Tension module
4. Fatigue resistance
5. Seam strengths
6. Puncture resistance
7. Tear resistance
8. Wetting and drying stability
9. Burst strength

c.Connection tests for reinforced soil walls (RSW)

d.Direct shear box

1. Modified direct shear box
2. ASTM type

e.Pull-out tests for RSW

f.In-soil strength test

g. Hydraulic properties

1. Permittivity
2. Transmissivity

h.Tests related to various reduction factors in design

1. Installation damage
2. Durability from environmental considerations (chemical and biological)
3. Durability from exposure to UV considerations
4. Creep, including the conventional concept of timetemperature superposition and the Stepped Isothermal Method (SIM)

• Elements of a reinforced soil wall and function of each element, selection of each element, limit state approach, design principles, external and internal stability, codal provisions, FHWA and BS 8006, construction of RS walls, causes of failures, numerical example.

• Geosynthetics in unpaved roads – Giroud and Noiray approach (1981).

• Geosynthetics in paved roads – Milligan, Houlbsy and others approach (1989-90).

• Type of landfills, their functions and related environmental issues
• a. Municipal garbage landfills
• b. Construction debris fills
• c. Industrial landfills
• d. Ash ponds, slag dumps, etc.
• e. Ore tailings, such as copper, zinc, aluminum ores
• f. Specialty waste landfills including for toxic and biohazardous sold materials
• g. River and harbor dredging fills
• h. Radioactive waste dumps

• The physical and chemical characteristics of solids, liquids (leachates) and gases generated by such landfills over time including toxicity, pH etc

• Identify the various components of landfills and the scope for use of geosynthetics and geocomposites for each of such functions.These could include but not be limited to:
• a. Slope stabilization including use of reinforced soil
• b. Providing an impervious blanket and its protection, containment systems
• c. Filtration
• d. Separation of various layers
• e. Erosion protection
• f. Reinforcement of above geosynthetics systems
• g. Chemical reaction of material of geosynthetics with the solid, liquid and gaseous products of the land fill, deterioration of various systems with time.