Detailed Specification for Providing and Laying CAGE Stone Pitching for Earthen Dam
1. Scope of Work
This specification outlines the requirements for providing and laying CAGE stone pitching with mechanically double twisted galvanized wire mesh for an earthen dam. The work includes:
- Laying stone pitching with wire mesh.
- Provision of murrum bedding.
- Hand packing and trimming.
- Dressing of slopes.
2. Materials
2.1 Stone Pitching
- Type of Stone: Stones should be clean, hard, dense, and durable, free from cracks, organic impurities, and other defects.
- Size of Stone: Stones should have a minimum dimension of 225 mm perpendicular to the face of the pitching. The exposed face of each stone should not be less than 0.02 m² in area.
2.2 Wire Mesh
- Type: Mechanically double twisted and galvanized wire mesh.
- Mesh Size: Mesh openings should not exceed 75x75 mm.
- Wire Specifications: Wire should comply with IS 16014:2018 standards for mechanically woven, double-twisted, hexagonal wire mesh gabions[1].
2.3 Murrum Bedding
- Thickness: 10 cm thick.
- Material: Murrum should be approved by project management consultants and free from organic impurities[2].
3. Construction Methodology
3.1 Preparation of Site
- Site Clearance: Clear the site of all vegetation, roots, and debris. Remove tree roots to a minimum depth of 1.20 meters below ground level.
- Excavation: Excavate to the required depth and dimensions as per the drawings. Over-excavation should be backfilled with compacted gravel or murrum.
3.2 Laying of Murrum Bedding
- Levelling and Spreading: Spread murrum evenly over the prepared surface to a thickness of 10 cm.
- Compaction: Compact the murrum bedding using a vibro roller to achieve a smooth and even surface[2].
3.3 Laying of Stone Pitching
- Placement of Stones: Hand-pack stones tightly together to minimize voids. Place stones with their largest face exposed.
- Wire Mesh Installation: Lay the galvanized wire mesh over the stones and securely tie it. Ensure the mesh is double twisted for stability and durability[1].
3.4 Trimming and Dressing
- Trimming: Trim slopes to the required profile and dimensions as per the drawings.
- Dressing: Dress the finished surface to achieve a neat and uniform appearance.
4. Quality Control
4.1 Material Testing
- Stone: Test stones for hardness, density, and durability.
- Wire Mesh: Test wire mesh for compliance with IS 16014:2018 standards[1].
- Murrum: Test murrum for particle size distribution and compaction properties[2].
4.2 Inspection
- Site Inspection: Conduct regular inspections to ensure compliance with specifications.
- Final Inspection: Perform a final inspection upon completion to ensure all requirements are met.
5. Measurement and Payment
5.1 Measurement
- Measure the work in square meters of the finished surface area of stone pitching.
5.2 Payment
- Payment will be made at the unit rate per square meter as specified in the Bill of Quantities. The rate includes the cost of all materials, labor, equipment, and other incidental expenses required to complete the work as per the specifications.
References
[2] IS 16014 (2012): Mechanically woven, double -twisted, hexagonal Wire ...
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