1. Scope
Covers all operations related to:
- Excavation, filling, and disposal of soil, rock, and other materials.
- Dewatering during earthworks.
- Preparation of foundations, trenches, pits, and embankments.
- Compaction and replacement of unsuitable material.
- Special works such as cofferdams, cuttings, and borrow pits.
2. Definitions
- Excavation → Removal of soil, rock, or other ground material by digging, blasting, ripping, or dredging.
- Foundation excavation → Excavation for building or structural foundations, usually below ground level.
- Trench excavation → Excavation for pipelines, cables, drains, or small strip foundations.
- Cutting → Large-scale excavation to form road/rail platforms.
- Embankment → Formation built up with excavated or borrowed material.
- Filling/backfilling → Replacing excavated spaces with selected material.
- Borrow pits → Places from where fill material is taken for embankments.
- Over-excavation → Excavation deeper/wider than required, usually backfilled with concrete or approved fill.
- Dewatering → Pumping/removing groundwater to keep excavation dry.
3. General Principles of Measurement
- Excavation measured in cubic meters (m³).
- Disposal (within site or off-site) measured separately in m³ with lead (distance).
- Fill/backfill/compaction measured in m³.
- Trenches measured in m³ but classified by width/depth bands.
- Cuttings (roads, canals, railways) measured in m³.
- Topsoil stripping measured in m² or m³ with specified depth.
- Dewatering measured in m³ of water removed or as item/lump sum if continuous pumping.
- Classification of material (soft soil, hard soil, soft rock, hard rock) must be stated in BOQ or defined in contract.
4. Subdivision of Work Items
Earthworks are divided into distinct measurable operations:
A) Excavation
- Topsoil stripping (to a specified depth).
- General excavation (site levelling, foundation pits, trenches).
- Excavation in cuttings (roads, railways, canals).
- Excavation in cofferdams or below water table.
- Excavation for structures (foundations, basements, retaining walls, wells, shafts).
Units: m³
B) Filling and Embankment
- Filling in foundations, plinths, behind walls.
- Filling in road/rail embankments or canals.
- Borrow material brought from outside sources.
- Layering and compaction included unless otherwise stated.
Units: m³
C) Disposal of Excavated Material
- Disposal on site (spreading, levelling).
- Disposal to spoil heaps (measured with lead).
- Disposal off-site to approved dump area.
- Leads classified in ranges (e.g., up to 50 m, 50–200 m, 200–500 m, >1 km).
Units: m³
D) Special Earthworks
- Dewatering (pumping, well-point systems).
- Groundwater cutoff walls (if included).
- Cofferdams, caissons.
- Replacement of unsuitable material.
Units: m³ or item (lump sum)
5. Information Required in Item Descriptions
Every BOQ item must clearly mention:
- Type of material (soft soil, hard soil, rock, mixed).
- Excavation method (mechanical, manual, blasting, dredging).
- Depth/width ranges (e.g., trench excavation not exceeding 1.5 m deep, 1.5–3.0 m deep).
- Location (below water table, dry excavation, confined space).
- Disposal requirements (within site, stacked, carted away with distance).
- Compaction details (layer thickness, required density).
6. Examples of CESMM4 BOQ Items (Class E)
- Excavation in ordinary soil for foundation trenches up to 1.5 m depth including disposal within 50 m – measured in m³.
- Excavation in hard rock (blasting prohibited) for basement up to 3 m depth – measured in m³.
- Stripping of topsoil 300 mm thick – measured in m².
- Dewatering of foundation pit (10 m × 10 m × 3 m deep) by pumping – measured as item.
- Backfilling with approved soil in layers not exceeding 200 mm, compacted to 95% Proctor density – measured in m³.
- Construction of embankment from borrow pits with compaction – measured in m³.
- Disposal of surplus excavated material to dumping ground 2 km away – measured in m³.
- Excavation below water table using cofferdam and pumping – measured as item or in m³ depending on contract.
7. Practical Notes
- Classification disputes (soft soil vs. rock) are common → clear definitions in contract avoid disputes.
- Separate items should be provided for different strata, excavation methods, and depth ranges.
- Overbreak/extra excavation → measured only if instructed by Engineer.
- Compaction testing costs usually included in BOQ preliminaries, unless measured separately.
- Safety: Proper shoring, benching, or strutting for deep excavations must be considered in method but not separately measured unless specified.
- Water table conditions greatly affect cost → BOQ should clearly mention if below/above water table.
✅ Summary:
Class E (Earthworks) in CESMM4 provides a structured system to measure all excavation, filling, disposal, and related operations. Proper classification of soil/rock, depth ranges, and disposal requirements ensures fair pricing and avoids disputes.
