Finished levels would be marked on temporary pegs fixed outside the limit of spreading. Filling would be started after the approval of the Engineer. Transport of material to the required location from the stock pile would be carried out by Dump Trucks and loading would be done using a back hoe loader.
• Where the embankment fill is more than 500mm and less than 3.0m, the top 500mm of the embankment would be filled by the embankment type 1 material and the embankment fill is less than 500mm, the lower layers would be filled by embankment type 2 material.
• If the materials are too wet, it would be dried using aeration. I.e. Spread and exposed to sun if required to be scarified using a back hoe loader or manually. In case the material is too dry, water would be added manually before leveling and mixed with the use of loader shovel or by manual means depending on the space available. Water would be supplied by the water tanker and stocked at site using the barrels for wetting embankment material.
• Embankment filling material types would be selected as follows:
Type I – maximum dry density under standard compaction not less than 1600 kg/m3. (For top 500mm); and
Type II – maximum dry density under standard compaction not less than 1500 kg/m3. (For lower layers below 500mm)
• Method of rolling – depending on the site conditions, 5 ton roller or an 8-10 ton roller would be applied in rolling the embankment material.
Rolling would be done from lower edge to center except for lower edge to higher edge on super-elevated sections.
• Horizontal alignment would be checked by the SE/TO with reference to the level pegs. Compaction would be done using 8-10 ton roller or 5 ton roller depending on the site condition. The required no of passes of the roller would be checked by the supervisor to achieve the specified compaction.
• If any water is collected during the construction, it would be drained out using a water pump, by bailing out or by making a natural drain out method (provide a drain in the natural slope).
5.3 Placing & Compaction of Embankment Material.
• The top 500mm of the embankment would be constructed using type I material as given in sub section 1708.1 and the lower layers of the embankment would be constructed using type II material as given in sub section 1708.1 unless otherwise specified.
• The material placed on the road bed would be thoroughly broken down throughout the layer by means of a motor grader.
• During such processing the layer would be frequently bladed using the grader to bring oversize material to the surface to facilitate breaking down. The embankment material would be firmly spread in layers not more than 225mm.
• Material would be placed in successive layers whose planes are parallel to the final road surface, wherever this is practicable and each successive layer shall be placed only after the previous layer has been tested and found satisfactory as specified.
• Any water required before material is compacted would be added to the materials in successive applications by means of water bowsers fitted with sprinkler bars or by means of pressure distributors. The water would be thoroughly mixed with the material to be compacted by means of a motor grader. Mixing would be continued until the required amount of water has been added and until a uniform mixture is obtained.
• Excess material would be trimmed according to the given line and level either manually or by mechanical means.
Compaction trials would be carried out to ascertain the number of passes for 8 – 10 ton roller and 5 ton roller required to achieve the specified compaction and to confirm the proposed layer thickness.
• Vibrating roller would be applied for the purpose of compaction and the top 500mm of the embankment would be compacted to a density not less then 95% of the maximum dry density and the lower layers of embankment and the foundation would be compacted to a density not less than 93% of the maximum dry density.
• The alternative the degree of compaction would be assessed by the number of passes of the roller.
• If the result of any test shows that the density is less then what is required, further compaction would be carried out to obtain the required density.