Technical Specification for Earthwork | Highway Construction

Technical Specification for Earthwork as per MORTH 5^th Revision Section 300

These Technical specification shall apply to the construction of embankment including sub grades, earthen shoulder and miscellaneous backfills.

1. In Backfilling the compacted thickness of each layer shall not be more than 150 mm.
2. The compacted thickness of each layer for embankment shall not be more than 250 mm when vibratory roller is used and not more than 200 mm when 80-100 kn static roller is used.
3. The maximum size of material should not exceed 75mm for embankment and 50mm for Subgrade, In  such cases it shall not more than two third of the compacted layer thickness.
4. The minimum density requirement for embankment material is – 1.52 gm/cc for upto 3m heigh and 1.60 gm/cc for more than 3m height.
5. The minimum density requirement for subgrade/ Earthen shoulder / Backfill material is 1.75 gm/cc
6. The materials “liquid limit” and “plasticity index” should not exceed 50% and 25%.
7. The materials “free swell index” should not more than 50%.
8. The maximum depth of the Borrow pit should not exceed 1.5m.
9. The minimum compaction requirement- for Subgrade/ shoulders is 97% and for embankment 95% min.
10. The moisture content of each layer at the time of compaction test is acceptable in range of 1% above to 2% below of OMC (from MDD).

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