Soils

Soils

1. Soil Analysis

   • Understand geology of the site
     • Soil profile is made
       • Ground survey profile covers the site

2. Micro-Assessment

   • establish nature, character and depth
   • establish mechanical properties
   • establish possibility of phsyical and chemical profile of the site
   • define ground water quality

3. Ground

   • Rocks
     • Igneous
       • granite
     • Sedimentary
       • sandstone / limestone
     • Metamorphic
       • marble
   • Soils
     • 3 elements
       • particles
       • air
       • voids
     • Physical properites
       • permeability
         • void ratio
           • more pockets of air more susceptible soil is to manipulation
             • leads to...
               • inundation
               • soil slippage
               • settlement
               • horizontal/vertical movement
       • particle size
         • fine
           • cohesive
             • clay
         • coarse
           • non-cohesive
             • sand/gravel
         • organic
           • peat

4. Particle Size Distribution

   • Coarse Soils
     • large particles
       • large spaces
   • cohesive soils
     • small pores
       • low permeability

5. Particle Size Classification

   • coarse
     • non - cohesive
       • highly permeable
     • very loose
       • non plastic
     • large pores
       • higher drainage run
     • loosely packed
       • lower strength
   • fine
     • cohesive
       • low permeability
     • very tight
       • plastic
     • small pores
       • lower drainage run
     • tightly packed
       • higher strength

6. Clay

   • irregular flakes of secondary sedimentary minerals
   • higher plasticity - easily moulded
   • lower permeability - as it drains
   • difficult to modify - cant compact or consolidate
   • once modified it reatins shape and is less susceptible to frost heave / erosion
     • shrink and swell still present and seasonal change

7. Treatment

   • Compaction
     • removal of air
   • Consolidation
     • removal of water