METHODOLOGY FOR SLOPE PROTECTION WORKS (SLOPE PITCHING) IN HIGH EMBANKMENTS
(Acceptance criteria: Ref. Sec2500 of MORT&H)
This work will consist of covering the slopes of guide bunds, training works and road embankments with stone, boulders, cement concrete blocks or stones in wire crates over a layer of granular material called filter.
Equipment’s, Tools & Plants Required:
- Hand Tools
- Water tanker
- Wooden Form work
The compacted layers shall be trimmed to the required slope and profile as per the approved drawing using line and pegs. Any depression shall be filled up and compacted thoroughly using wooden rammers.
Placing of filter layer:
Suitable material (approved as filter material) shall be placed manually over prepared base and shall be compacted in uniform layer of 150mm maintaining slope and profile as per the approved drawing.
Dry rubble pitching:
Over the prepared filter layer dry pitching shall be carried out either with stones of specified quality or concrete blocks (of M15 grade) having an average weight of 45 Kg maintaining slope and profile as per the approved drawing. Pitching shall be commenced from bottom of the slope and continued to the top. In case of rubble pitching care shall be taken to minimize void between the stones, which however shall be filled up with spalls of suitable size.
Construction of chute drain:
Chute drain shall be constructed at 25M C/C along the road alignment parallel to the slope of pitching as per the dimension, slope and profile as mentioned in approved drawing. Firstly 100 mm thick levelling course (M15 grade) shall be placed along the embankment slope and shall be extended to the Kerb face. The drain wall shall be constructed with PCC M15 concrete. At junction of chute drain with kerb, the kerb shall be cut to the required dimension.
Construction of stone masonry Toe drain:
Construction of Toe drain shall be done simultaneously with the slope pitching. Soil at toe portion shall be trimmed, leveled and compacted to the required shape and size. Boulder of specified quality shall be laid in CM (1:3) maintaining the dimensions, slope and profile as mentioned in approved drawing.
Curing of concrete shall be continued for 7 days by sprinkling of water.