Building Technology 1: Sitework and Earthworks

Earthworks

• Acronyms:

  • AASHTO: American Association of State Highway and Transportation Officials
  • ANSI: American Nurserymen’s Specifications Institute
  • ASTM: American Society for Testing Materials
  • DPWH: Department of Public Works and Highways (Philippines)
  • USCS: Unified Soil Classification System

• Definitions and Standard Tests:

  • AASHTO Soil Classification System classifies inorganic soils for subgrade suitability based on drainage and bearing capacity.
  • Particle sizes defined by AASHTO include:
    • Boulders: > 75 mm
    • Gravel: 75 mm to No.10 sieve
    • Coarse Sand: No.10 to No.40 sieve
    • Fine Sand: No.40 to No.200 sieve
    • Silt-Clay: passing No.200 sieve

• Atterberg Limits:

  • Tests on soils passing No.40 sieve determine:
    • Liquid Limit (LL): moisture content where soil transitions from liquid to plastic state.
    • Plastic Limit (PL): water content at which soil starts to crumble when rolled to 3.2 mm.
    • Plasticity Index (PI): PI = LL - PL, indicating the moisture range over which soil behaves plastically.

• Fill Materials:

  • Used to elevate grades or as compacted deposits, include soil, crushed stone, and sand.
  • Classified under USCS as GW, GM, GP (gravels) and SW, SM (sands).

• Borrow Fill:

  • Selected laboratory-approved pit-run gravel or similar materials with < 35% passing the No.200 sieve.

Termite and Bukbok Proofing

• Methods:
  • Physical Barrier: Allows for moisture management.
  • Chemical Barrier: Provides treatment to deter termites.
  • Bait System: Attracts and eliminates termites from the area.

Roads and Parking

• Subgrade and Base Course Materials:
  • Ensures stability and support for surfaces.
• Surface Paving Material:
  • Final layer material that interacts with vehicle traffic and weather.

Riprap (Rock Lining)

• Defined as layered stone used to prevent erosion and scouring of structures or embankments.
• Subject to considerable energy, must be sound and free of defects.
• Gradation ranges from 2 inches to 42 inches in diameter to resist displacement from moving water.

Gabion System

• Composed of wire-enclosed riprap; constructed from wire mesh filled with small riprap.
• Used to reinforce slopes and protect areas from erosion.