Roads Construction:

Soil Road Construction Process Description

Soil road construction involves preparing and compacting native or imported soils to create stable, durable access routes, typically used in temporary or low-traffic applications such as solar plant internal roads. Proper grading, drainage, and compaction are critical to road performance and longevity.

  1. Site Clearing and Grubbing
  • Remove vegetation, roots, debris, and topsoil from the designated road alignment.
  • Dispose of cleared material in approved disposal areas.
  • Ensure a minimum clearance width as per project drawings and access requirements.
  1. Stripping and Excavation
  • Strip the top organic soil layer (typically 15–30 cm) to expose firm subgrade.
  • Excavate or cut to the designed road level and cross-section (camber or crown).
  • Fill low areas and backfill depressions using suitable material.
  1. Subgrade Preparation
  • Level and grade the exposed subgrade surface using graders.
  • Moisture condition the subgrade (add water if dry, aerate if wet) to achieve optimal moisture content.
  • Compact the subgrade using a vibratory roller (minimum 95% Modified Proctor density, or as per specification).
  1. Embankment Formation (if required)
  • Place soil in horizontal layers (150–200 mm loose thickness).
  • Compact each layer to the specified density before placing the next.
  • Ensure side slopes are formed and compacted as per design (typically 1:2 or 1:3 slope).
  1. Placement of Selected Fill / Wearing Course
  • Import selected granular material (e.g., well-graded soil, murram, or laterite) for the road surface.
  • Spread the material uniformly using motor graders.
  • Adjust moisture content for compaction.
  • Compact in layers using vibratory rollers to the required density (typically 98% Modified Proctor).
  • Form camber (2–3% cross fall) for surface drainage.
  1. Final Grading and Finishing
  • Final trim and level the road surface using graders.
  • Compact the final surface layer to ensure uniformity and smoothness.
  • Ensure proper side drains or ditches are formed to channel stormwater away from the road.
  1. Drainage and Culverts (if applicable)
  • Construct side drains (V- or trapezoidal-shaped) parallel to the road.
  • Install culverts at designated low points or crossings using concrete or HDPE pipes.
  • Ensure culvert inlets and outlets are protected with headwalls or riprap to prevent erosion.
  1. Quality Control
  • Perform field density tests (e.g., sand cone or nuclear density tests) on subgrade and surface layers.
  • Check longitudinal and transverse gradients, camber, and alignment using survey equipment.
  • Inspect for soft spots or poor compaction and rectify as needed.
  1. Safety and Environmental Considerations
  • Implement dust control measures (e.g., regular water spraying).
  • Ensure operators wear appropriate PPE (helmets, vests, boots).
  • Avoid soil erosion and sediment runoff into adjacent areas by constructing temporary silt traps or berms.