What earthworks include and how volume is calculated

The line items of earthworks

• Clearing: removal of topsoil or unsuitable material (clay, loose fill) down to competent ground.
• Cut or excavation: removal of material to bring the ground down to design level; in urban areas it includes basement excavation.
• Fill or embankment: placing material in layers to raise the ground to design level.
• Compaction: densifying each layer with controlled moisture to the percentage specified by the design.
• Hauling: transport of surplus material to authorized disposal or borrow material to the site.
• Grading and fine grading: final shaping of the pad and roads with a motor grader.
• Sub-base or breaker layer: granular layer that receives the floor or pavement.

How volume is quantified

Everything starts with a topographic survey of natural ground and the design levels. With both, cross sections are drawn at regular intervals or a digital terrain model is built; the difference between the existing and design surfaces, integrated across the site (average end-area or prism method), gives the cubic meters of cut and fill.

Volume changes state: material in bank (compact in the ground) swells when excavated, occupies more loose in the truck and shrinks again when compacted. That is why a serious quote specifies whether m³ are measured in bank, loose or compacted, and uses swell factors by soil type.

What the lab checks

• Proctor test: defines the maximum density and optimum moisture of the fill material.
• Field density: verifies on each layer that the design compaction percentage was reached.
• Material classification: gradation and plasticity to decide whether site material is suitable for fill.
• Layer thickness: compacting in thin, uniform layers is what guarantees the result; thickness is set by the design and the equipment.

What the contractor should deliver

That is how we built the pads at Capithal Park, Centro Logístico de Jalisco and the Ubika plazas: with prior quantities, lab testing on every layer and handover with verified levels.

• Quantities with cross sections or digital model and the measurement criterion (bank, loose, compacted).
• Schedule by work front and weekly report of executed m³.
• Lab tests per layer and final levels verified by survey.
• Disposal receipts for hauled material.