GEOTECHENGG PRELIMS-MIDTERMS

Soil particles smaller than 0.001 mm sieve

Colloids

Soil transported and deposited by wind.

Aeolian

Molten rock located deep inside the Earth

Magma

Transitions from a solid to a semi-solid

Shrinkage Limit

Relative compactness of natural cohesionless soil

Density Index (Relative Density)

Density Index

Relative Density

Transitions from a plastic to a liquid

Liquid Limit

The ratio of the plasticity index to the flow index

Toughness Index

The ratio of the volume of voids to the volume of solids

Void Ratio

Ratio of weight of water to weight of solids

Water Content

The geological process in which earthen materials are worn away and transported by natural forces such as wind or water

Erosion

The largest earth dam in the world

Oroville Dam

Space no occupied by soil

Voids

The process of changing the composition and texture of rocks (without melting) by heat, pressure

Metamorphism

Particles passing 0.002 mm sieve but larger than 0.001 mm

Clay

Particles passing 0.075 mm (No. 200) sieve but are larger than 0.002 mm

Silt

Relative compactness of both cohesive and cohesionless soil

Relative Compaction

Father of modern soil mechanics

Karl Terzaghi

Ratio of volume of voids to the volume total

Porosity

Process of breaking down rocks by mechanical and
chemical processes into small pieces

Weathering

Refers to the ability of soil or rock to allow fluids to pass through its pores or fractures

Permeability

The tendency of soil to increase in volume when it absorbs water, critical for soils like clays

Swell Potential

A laboratory test to find the optimum moisture content at which soil can be compacted to its maximum density

Proctor Test

The soil's resistance to shearing forces, which cause layers to slide past one another

Shear Strength

A graph that shows the relationship between water content and dry density of soil

Compaction Curve

A law which governs the flow of fluid through porous media

Darcy's Law

A test that measures the mechanical properties of soil, including its strength and cohesion, under different conditions

Triaxial Test

Layers of sedimentary rock or soil with consistent characteristics that distinguish them from layers above or below

Strata

A ground improvement technique that densifies loose, granular soils by using a vibrating probe

Vibroflotation

Material used to refill an excavation, usually to support a structure or restore the original ground level

Backfill

The controlled use of explosives to break up rock or soil, commonly used in mining and construction to create foundations or tunnels

Blasting

The volume of fluid passing through a given area per unit time

Flow Rate

The process by which soils decrease in volume over time under sustained load, primarily due to the expulsion of water from pore spaces.

Consolidation

The ratio of the volume of voids to the volume of solids in a soil sample

Void Ratio

The proportion of different-sized particles in a soil sample

Grain Size Distribution

A test to determine the size distribution of fine-grained soils by measuring their settling velocity in water

Hydrometer Analysis

The ability of an aquifer to transmit water horizontally, depending on the permeability of the material and the thickness of the aquifer

Transmissivity

An empirical equation used to estimate the hydraulic conductivity of soils based on grain size distribution

Hazen's Formula

Fluid movement in parallel layers, with minimal mixing between the layers

Laminar Flow

A procedure used to determine the liquid limit of soils, which helps classify soil types and predict their behavior under load

Casagrande Method

Transitions from a semi-solid to a plastic state

Plastic Limit