CHAPTER : 7.0 GEOSYNTHETICS AND REINFORCED EARTH
|7.1||Sub-Surface Drain with Geotextiles
Construction of sub surface drain 200 mm dia using geotextiles treated with carbon black with physical properties as given in clause 702.2.3 formed in to a stable network and a planar geocomposite structure, joints wrapped with geotextile to prevent ingress of soil, all as per clause 702 and approved drawings including excavation and backfilling.
|7.2||Narrow Filter Sub-Surface Drain
Construction of a narrow filter sub-surface drain consisting of porous or perforated pipe laid in narrow trench surrounded by a geotextile filter fabric, with a minimum of 450 mm overlap of fabric and installed as per clause 702.3 and 309.3.5 including excavation and backfilling.
Laying Paving Fabric Beneath a Pavement Overlay
Providing and laying paving fabric with physical requirements as per table 700-16 over a tack coat of paving grade Bitumen VG 10 penetration, laid at the rate of 1 kg per sqm over thoroughly cleaned and repaired surface to provide a water resistant membrane and crack retarding layer. Paving fabric to be free of wrinkling and folding and to be laid before cooling of tack coat, brooming and rolling of surface with pneumatic roller to maximise paving fabric contact with pavement surface.
Laying Boulder Apron in Crates of Synthetic Geogrids
Providing, preparing and laying of geogrid crated apron 1 m x 5 m, 600 mm thick including excavation and backfilling with baffles at 1 metre interval, made with geogrids having characteristics as per clause 704.2, joining sides with connectors/ring staples, top corners to be tie tensioned, placing of suitable cross interval ties in layers of 300 mm connecting opposite side with lateral braces and tied with polymer braids to avoid bulging, constructed as per clause 704.3. filled with stone with minimum size of 200 mm and specific gravity not less than 2.65, packed with stone spalls, keyed to the foundation recess in case of sloping ground and laid over a layer of geotextile to prevent migration of fines, all as per clause 704 and laid as per clause 2503.3 and approved design.
Reinforced Earth Retaining Wall
Reinforced earth retaining walls have four main components as under: a) Excavation for foundation, foundation concrete and cement concrete grooved seating in the foundation for facing elements (facia material). b) Facia material and its placement. c) Assembling, joining with facing elements and laying of the reinforcing elements. d) Earthfill with specified material as per specification to be retained by the wall. (This will be paid extra as per C below).
|(i) Facing elements of RCC.||sqm||1197.00|
|(ii) Assembling, joining and laying of reinforcing elements.|
A With reinforcing element of steel / Aluminium strips / polymeric strips. 1.Galvanised carbon steel strips.
|Type1||1. Galvanised carbon steel strips.||metre||302.00|
|Type 2||2 .Copper Strips.||metre||291.00|
|Type 3||3. Aluminium Strips.||metre||256.00|
|Type 4||4. Stainless steel strips.||metre||279.00|
|Type 5||5. Glass reinforced polymer/fibre reinforced polymer/ polymeric strips.||metre||362.00|
|B With reinforcing elements of synthetic geogrids.||sqm||188.00|
|C Earth fill with specified specifications.as per