Soils Final Exam Review

Front 1

Define Soils Summary

Back 1

• Natural Material
• Mineral or organic particles weakly or un cemented
• Made up of (solid,Air,Water)

Front 2

Define Rock

Back 2

• Natural Aggregate connected by strong permanent cohesive forces

Front 3

What is a Rock Cycle

Back 3

• Consolidated particles turn into rock over Time, under weight of overlying material or other geological processes

Front 4

How can Rocks be Formed?

Back 4

• Solidify from melt
• precipitate from solutions
• metamorphosed from other rock types

Front 5

What are the 3 Inner layers of earth?

Back 5

• Crust
• Mantle
• Core

Front 6

What were the first Rocks Formed?

Back 6

Igneous

Front 7

How are Igneous Rocks formed?

Back 7

From the cooling of molten material on the surface

Front 8

3 Rock types?

Back 8

• Igneous
• Sedimentary
• Metamorphic

Front 9

Igneous Rock Characteristics

Back 9

• Coarse or Fine Grain
• Slow Cooling (Below Crust) (intrusive)
• Rapid Cooling ( reaches surface)(extrusive)
• Hard & good bearing capacity`

Front 10

Sedimentary Rocks

Back 10

• Minerals are transported by wind, water, ice...
• deposited in layers and form sediments
• not as strong as igneous

Front 11

Metamorphic Rocks

Back 11

• Igneous and Sedimentary Rocks are metamorphosed under high pressure or heat
  

Front 12

How Rock Weathering Occurs?

Back 12

• Mechanical
• Chemical

Front 13

Chemical Weathering is....

Back 13

Processes such as

• Oxidation
• solution
• carbonation
• leaching
• hydrolysis

Front 14

Soils produced by rock weathering can be categorized by

Back 14

its relative location of the parent rock

• Residual
• Transidual

Front 15

Residual Soils

Back 15

Soils Remain where they were formed

Front 16

4 Common transporting agents

Back 16

• Gravity
• Running Water
• Wind
• Glaciers

Front 17

How Soils types can be Defined

Back 17

1. Based on Nature - Mineral or Organic
2. Particle Size - Coarse or Fine Grained
3. Behavior - Cohesive (clay )or Cohesionless (cobble,sand)

Front 18

Grain Size analysis is used for...

Back 18

Grain size distribution of sample

Front 19

Grain Size analysis is made up of 2 parts

Back 19

1. Sieve Analysis: Coarse Grain >= 75 micro
2. Hydrometer analysis: Fine Grain <75 micro

Front 20

Whats D10 on grain size distribution?

Back 20

The diameter that 10% of the sample will be finer than.

Front 21

Atterberg Limits includes:

Back 21

• Liquid Limit
• Plastic Limit
• Shrinkage Limit

Front 22

Liquid Limit is

Back 22

The water content which soil will Flow

can be determined by Casagrande Apparatus

Front 23

Plastic Limit is

Back 23

Moisture Content when soil can no longer be rolled into 3.2 mm diameter without breaking in segments of 3-10 mm

Front 24

Shrinkage Limit is

Back 24

Moisture Content at which soil is completely saturated

• Below SL, any MC change will not change volume
• Above SL, MC change will change volume

Front 25

Site investigation is

Back 25

Exploration if the ground conditions, to enable geotechs to make informed design decisions

Front 26

6 Steps of Site Investigation (SI)

Back 26

1. Desk Study
2. Site Recon
3. Planning Field Program
4. Execute Field Program
5. Lab Testing
6. Reporting

Front 27

Desk Study includes...

Back 27

• Location and topographical maps
• Government land use regulations
• Aerial photos
• Geological maps

Front 28

Site Reconnaissance

Back 28

• Geo-tech visits site
• Validate desk study
• Observe land features
• Take photos

Front 29

Develop a Field program specifying...

Back 29

• SI methods & number of bore holes or test-pits
• Depths of SI
• Sampling Methods & frequency
• Testing methods

Front 30

Info from field program include...

Back 30

• Types of Soils
• Thickness of soils
• Groundwater condition
• Soil Samples for testing
• In Situ test results

Front 31

Methods of SI (2)

Back 31

• Intrusive
• Non-Intrusive

Front 32

Intrusive SI methods includes (2):

Back 32

• Boreholes
• Test Pits

Front 33

Drill Boreholes SI include:

Back 33

• Auger Drilling
• Hammer Drilling
• Rotary Drilling
• Sonic Drilling
• Cone Penetration
• Direct Push

Front 34

Common Auger Drilling Methods

Back 34

• Solid Stem
• Hollow Stem

Front 35

Test Pits are:

Back 35

• Excavations to show soil profile
  
• usually not more than 3m deep
• can be inspected visually
• limited to groundwater level

Front 36

During Borehole you should (3).

Back 36

1. Field logging is a must
2. In situ testing
3. Sample collection

Front 37

Common Situ testing

Back 37

the standard penetration test (SPT)

Front 38

SPT # (N value)

Back 38

the number of blows required to penetrate each 6in increment.

The N-Value is the number of blows required to penetrate the last to increments of 6in each (12in)

Front 39

Ground water elevation is...

Back 39

the level which the water rises in an open borehole

Front 40

Typical data in a borehole log are:

Back 40

• Depth
  
• Sample type and location
• Soil description
• In situ testing results
• Moisture Content
• Groundwater level

Front 41

Compaction mean

Back 41

Densification of soils by reducing the air voids

Front 42

3 important effects of comaction

Back 42

• Increase Shear Strength
• Decrease further settlement
• Decrease permeability

Front 43

The degree of compaction is measure by

Back 43

Dry Unit Weight

Front 44

Compaction effort means

Back 44

The energy delivered by mechanical mean

Front 45

The optimal Moisture Content is:

Back 45

The max dry unit weight and associated moisture content

Front 46

The " Zero Air Void" (ZAV) line shows

Back 46

Theoretical dry unit weight when soil is fully saturated

Front 47

Standard Proctor Density (SPD)

Back 47

The laboratory determined max dry density

Front 48

The 3 factors affecting soil compaction are

Back 48

1. Moisture Content
2. Compactive Effort
3. Soil Type

Front 49

Compaction is affected by

Back 49

• Grain size distribution
• Shape
• Specific gravity
• type and amount of clay

Front 50

Which minerals cannot be compacted well

Back 50

• uniformly graded sands
• high plastic clays
• organic clays and silts

Front 51

Common variety of roller compactors

Back 51

• smooth wheel roller
• sheep foot roller
• pneumatic roller
• vibratory roller

Front 52

Compaction aims at

Back 52

• Increasing shear strength
• Decreasing further settlement
• Reducing permeability

Front 53

Soil Stabilization can be achieved by

Back 53

• Compaction
• Preloading
• Mechanical Stabilization
• Chemical Stabilization
• Using GeoSynthetics

Front 54

4 common Geosythetics

Back 54

• Geotextile
• Geonets
• GeoGrids
• Geomembranes

Front 55

Non Destructive field unit weight (density) tests

Back 55

• Nuclear moisture-density
• Non-nuclear gauge

Front 56

Destructive field unit weight

Back 56

• Drive cylinder
• Rubber Balloon
• Sand cone

Front 57

Pre Loading

Back 57

• adding a load to a potential construction site prior to structure being built
  
• works best with soft silty clays

Front 58

Geo synthetics

Back 58

• used to stabilize and reinforce soil masses

Front 59

Geo textiles

Back 59

• woven fabric
• used for soil reinforcement, drainage,filtration

Front 60

Geo grids

Back 60

• Larger openings than geotextiles
• used on poor soil that will be paved over
• improves slope stability

Front 61

Geonets

Back 61

• similar to geogrids but have intersecting ribs
• used for drainage

Front 62

Geomembranes

Back 62

• plastic sheets
• restrict movement of water or liquids
• ex. landfill liners

Front 63

Drive Cylinder

Back 63

• Density test
• used for cohesive soils
• a thin-walled cylinder is driven into the soil to remove sample

Front 64

Rubber Ballon

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• Density test
• Core a hole into the compacted fill and measure the mass of soil removed
• Place a rubber balloon over the empty hole with water in the apparatus

Front 65

define Water TABLE

Back 65

the locus points in the saturated zone in the subsurface where water pressure is zero

Front 66

Lab shear tests include

Back 66

• Unconfined compression test (cohesive soils)
• Direct shear test
• Triaxial test

Front 67

Capilarity

Back 67

the tendency of a liquid in a capillary tube to rise or fall as a result of surface tension

Front 68

Frost Heave

Back 68

vertical expansion of soil caused by freezing water

Front 69

List the Lab tests for finding the coefficient of permeability (k)

Back 69

• Constant Head (granular)
• Falling head ( fine & coarse)

Front 70

List Field tests for finding k

Back 70

Slug test

pumping test

tracer tests

Front 71

Aquifer

Back 71

a saturated permeable geological unit that can transmit a significant amount of water

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Aquiclude

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Opposite of aquifer. Cannot transmit water

Front 73

Aquitard

Back 73

a less permeable bed in a geological sequence

Front 74

Unconfined Aquifer

Back 74

a aquifer with its top exposed

Front 75

Confined aquifer

Back 75

An aquifer sandwiched between two aquitards

Front 76

Soil Strength is

Back 76

the capability of soil to resist forced induced by its self weight and applied loads

Front 77

Soil strength is primarily developed from its

Back 77

• shear strength
• shear resistance

Front 78

Mohrs Circle usage

Back 78

• can be used to represent the stress state of a soil element
• Find stress at a different orientation
• find max shear stress
• locate the orientation of the theoretical failure plane