Questions and Answers
Sheet Piles Must be deep enough in the soil to hold the load.
Borrow Pit Method 1- Find Elevations and Cut of soils
2- Fill in chart with the cut of the soils
3- Find H1, H2, H4 from chart (H1 is corners, H2 is outside of chart besides corners, and H4 is
the middles)
4- Use formula A(1(h1)+2(h2)+4(h4))/(4)(27) for A use 1 GRID size
Average Height Method 1- Find Elevations and Cut of soils
2- Fill in chart with the cut of the soils
3- Find H1, H2, H4 from chart (H1 is corners, H2 is outside of chart besides corners, and H4 is
the middles)
4- Use formula A*h(avg.)/27 for A use full LOT size, for h add H1, H2, and H4 and divide by
number of grid boxes
Frost Heaves - Water freezes during winter and produces a lens of ice beneath the particles
because the particles conduct the cold. The cold, ice expands by 9% and pushes outwards.
-Prevent with better drainage, new soil, or heating of the soil
Plastic Limit Moisture content at which soil starts to crumble
Special Numbers Mile = 5280ft
Acre = 43,560sf
Section = 640 acres
Water weight = 62.4 lbs/cf
Plastic Index Numerical difference between liquid and plastic limits
Liquid Limit Expressed as a % of dry weight
Point at which soil will start to flow and not compact
Dripline Minimum protection around a tree
Trench Safety Slope, Shore, Shield
5' deep requires shoring
4' deep required egress every 25' (ladder, stairs, board)
If using ladder, must go 3' above hole
Spoil pile 2' back from edge of hole
, Proctor Test Evaluates soil moisture density in relation under compaction effort
Modified Test
Used for high density loads
Determines max dry unit weight
Optimum Moisture Content The moisture content at which the maximum dry unit weight
of soil is attained
Moistures greatest influence on compaction
Greatest densification with least amount of work
Sheep's Foot Roller Best for a colloidal soil condition
Used exclusively with cohesive soils to allow for deep compaction of the materials
Used on clays or cohesive soils to push moisture out
200 Sieve A sieve that has 200 holes per inch
Materials that pass through are considered fine materials
Clays and Silts
Submation Total of the last two tests done on a soil boring log
Soil Requirements - ability to carry load
- stable
- withstand freeze, thaw
Soil Consist of Solids, Liquids, and Gasses
Weathering Processes Mechanical - physically breaking down of soil through weather
Chemical - chemically breaking down of soil through temperature changes, atmosphere, water,
chemicals
Engineering properties of soil Strength and Compressibility
Bearing Capacities
Soil Settlement and Slope Stability
Soils are made of various sizes and shapes True
Size and Shape affect soils capabilities and behaviors True
3 Soil Groups Non-Cohesive - Granular, Sands and Gravels
Cohesive - Fine, Clay and Silts
Organic - Peat, Fibrous
Classification Tests Determine determine size, shape, and % of particles in each soil
sample