COSC 354 - Chapter 2 Notes Exam Questions and Answers Already Passed Latest Update
2025-2026
Geotechnical Report - Answers A tool used to communicate the site conditions and
construction recommendations to the site-design, building design, and construction personnel.
Test Boring - Answers The actual method used to perform the subsurface exploration for
geotechnical reports.
Soil Samples - Answers Soil samples are taken back to the lab for further testing.
Moisture Testing - Answers Each soil sample is weighted, then dried, then weighed again.
Atterberg Limits - Answers The moisture content at which the soil changes state, typically
determined by the plastic limit and the liquid limit of the soil.
Plastic Limit - Answers The moisture content at which fine grained soil can no longer be
remolded without cracking.
Liquid Limit - Answers The moisture content where the soil starts to behave as liquid.
Plasticity Index - Answers Liquid limit - plastic limit (PI is an important value when determining
soil types).
Sieve Analysis - Answers This is how to determine the USCS (Unified Soil Classification System).
Permeability - Answers The capacity of the soil to allow water to pass through it.
High Permeability - Answers Good drainage, typically seen in sandy soils; clay soils have low
permeability.
Stiffness - Answers The resistance of the material to stress induced deformation.
Well Graded Soil - Answers Good mixture of a bunch of different sizes of soils.
Poorly Graded Soil - Answers All mediums and all smalls (but no larges), poorly graded because
it is not going to compact.
Uniformly Graded - Answers All smalls, all mediums, or all larges.
Gap Graded - Answers Larges and smalls, large gaps between particles.
Well Sorted - Answers All smalls.
Poorly Sorted - Answers Large range of sizes in the soils.
Groundwater - Answers Defined by any water below the ground surface.
Water Table - Answers Elevation at which soil is fully saturated.
, Hydrostatic Pressure - Answers The pressure that water exerts on a surface when its standing
still
Excavation - Answers Excavation is needed to reach undisturbed adequately firm soils
Excavation Safety - Answers When attempting to perform excavations, something must be put
in place to support the sides of the excavation to prevent soils from collapsing
Benching - Answers Typically a 1:1 ratio
Sloping - Answers Requires a larger area, so the soil does not slide back into the hole, this angle
is called the angle of repose
Shoring - Answers Supporting the sides of an excavation with an external system
2, 3, 4, 5, 25 Rule - Answers A set of guidelines for excavation safety
2 Rule - Answers Keep spoils 2' back from the excavation, so there is not a chance for the spoils
to fall back in
3 Rule - Answers Make sure your means of egress (typically a ladder) extends 3' past the top of
the excavation
4 Rule - Answers At 4', a ladder or stairs will be required for exit and egress
5 Rule - Answers At 5' depth, a trench must have a protective system in place (sloping, benching,
shoring, trench box)
25 Rule - Answers At 25' deep, all excavations must have an engineered shoring system
Benching Method - Answers A method of protecting employees from cave ins by excavating the
sides of an excavation to form one or a series of horizontal levels or steps, usually with vertical
or near vertical surfaces between levels
Sloping Method - Answers A method of protecting employees from cave ins by excavating to
form sides of an excavation that are inclined away from the excavation
Shoring Provision - Answers The provision of a support system for trench faces used to prevent
movement of soil, underground utilities, roadways, and foundations
Shoring or Shielding - Answers Used when the location or depth of the cut makes sloping back
to the maximum allowable slope impractical
Shore Box - Answers For smaller excavations, a shore box is typically used
Soldier Beams and Lagging - Answers Driven H piles with wood lagged infilled
Contiguous Piers - Answers Cylindrical concrete piers spaced closely enough that they form a
2025-2026
Geotechnical Report - Answers A tool used to communicate the site conditions and
construction recommendations to the site-design, building design, and construction personnel.
Test Boring - Answers The actual method used to perform the subsurface exploration for
geotechnical reports.
Soil Samples - Answers Soil samples are taken back to the lab for further testing.
Moisture Testing - Answers Each soil sample is weighted, then dried, then weighed again.
Atterberg Limits - Answers The moisture content at which the soil changes state, typically
determined by the plastic limit and the liquid limit of the soil.
Plastic Limit - Answers The moisture content at which fine grained soil can no longer be
remolded without cracking.
Liquid Limit - Answers The moisture content where the soil starts to behave as liquid.
Plasticity Index - Answers Liquid limit - plastic limit (PI is an important value when determining
soil types).
Sieve Analysis - Answers This is how to determine the USCS (Unified Soil Classification System).
Permeability - Answers The capacity of the soil to allow water to pass through it.
High Permeability - Answers Good drainage, typically seen in sandy soils; clay soils have low
permeability.
Stiffness - Answers The resistance of the material to stress induced deformation.
Well Graded Soil - Answers Good mixture of a bunch of different sizes of soils.
Poorly Graded Soil - Answers All mediums and all smalls (but no larges), poorly graded because
it is not going to compact.
Uniformly Graded - Answers All smalls, all mediums, or all larges.
Gap Graded - Answers Larges and smalls, large gaps between particles.
Well Sorted - Answers All smalls.
Poorly Sorted - Answers Large range of sizes in the soils.
Groundwater - Answers Defined by any water below the ground surface.
Water Table - Answers Elevation at which soil is fully saturated.
, Hydrostatic Pressure - Answers The pressure that water exerts on a surface when its standing
still
Excavation - Answers Excavation is needed to reach undisturbed adequately firm soils
Excavation Safety - Answers When attempting to perform excavations, something must be put
in place to support the sides of the excavation to prevent soils from collapsing
Benching - Answers Typically a 1:1 ratio
Sloping - Answers Requires a larger area, so the soil does not slide back into the hole, this angle
is called the angle of repose
Shoring - Answers Supporting the sides of an excavation with an external system
2, 3, 4, 5, 25 Rule - Answers A set of guidelines for excavation safety
2 Rule - Answers Keep spoils 2' back from the excavation, so there is not a chance for the spoils
to fall back in
3 Rule - Answers Make sure your means of egress (typically a ladder) extends 3' past the top of
the excavation
4 Rule - Answers At 4', a ladder or stairs will be required for exit and egress
5 Rule - Answers At 5' depth, a trench must have a protective system in place (sloping, benching,
shoring, trench box)
25 Rule - Answers At 25' deep, all excavations must have an engineered shoring system
Benching Method - Answers A method of protecting employees from cave ins by excavating the
sides of an excavation to form one or a series of horizontal levels or steps, usually with vertical
or near vertical surfaces between levels
Sloping Method - Answers A method of protecting employees from cave ins by excavating to
form sides of an excavation that are inclined away from the excavation
Shoring Provision - Answers The provision of a support system for trench faces used to prevent
movement of soil, underground utilities, roadways, and foundations
Shoring or Shielding - Answers Used when the location or depth of the cut makes sloping back
to the maximum allowable slope impractical
Shore Box - Answers For smaller excavations, a shore box is typically used
Soldier Beams and Lagging - Answers Driven H piles with wood lagged infilled
Contiguous Piers - Answers Cylindrical concrete piers spaced closely enough that they form a
