Advanced Soil Mechanics
Expert-defined terms from the Postgraduate Certificate in Geotechnical Engineering & Soil Mechanics course at London School of Planning and Management. Free to read, free to share, paired with a globally recognised certification pathway.
**Active Earth Pressure** #
**Active Earth Pressure**
Active earth pressure is the horizontal force exerted by soil on a retaining str… #
It is the pressure that occurs when the soil is in motion or can move, such as during an earthquake or when the wall is being pushed.
**Atterberg Limits** #
**Atterberg Limits**
Atterberg limits are a set of tests used to determine the critical water content… #
These limits include the liquid limit, plastic limit, and shrinkage limit, and they are used to classify soils and predict their behavior.
**Bearing Capacity** #
**Bearing Capacity**
Bearing capacity is the maximum load that can be supported by the soil without u… #
It is an important consideration in the design of foundations and other structural elements that bear on the soil.
**Consolidation** #
**Consolidation**
Consolidation is the process by which the volume of a soil decreases as the wate… #
This can occur due to the application of a load or the removal of water. Consolidation can take a long time to occur, and it is an important consideration in the design of foundations and other geotechnical structures.
**Darcy's Law** #
**Darcy's Law**
Darcy's law is an equation that describes the flow of water through porous media… #
It states that the flow rate is proportional to the hydraulic gradient and the permeability of the medium.
**Effective Stress** #
**Effective Stress**
Effective stress is the portion of the total stress on a soil that is carried by… #
It is calculated by subtracting the pore water pressure from the total stress. Effective stress is an important concept in soil mechanics because it controls the strength and deformation behavior of soils.
**Factor of Safety** #
**Factor of Safety**
Factor of safety is a measure of the reliability of a design #
It is defined as the ratio of the load-bearing capacity of a soil or structure to the applied load. A factor of safety of 2, for example, means that the soil or structure can support twice the applied load.
**Friction Angle** #
**Friction Angle**
Friction angle is a measure of the strength of a soil due to the friction betwee… #
It is an important parameter in the analysis and design of geotechnical structures such as slopes, embankments, and foundations.
**Permeability** #
**Permeability**
Permeability is a measure of the ability of a soil or rock to allow the flow of… #
It is an important parameter in the analysis and design of hydraulic structures such as dams, levees, and tunnels.
**Passive Earth Pressure** #
**Passive Earth Pressure**
Passive earth pressure is the horizontal force exerted by soil on a retaining st… #
It is the pressure that occurs when the soil is in a stable, unmoving state.
**Pore Water Pressure** #
**Pore Water Pressure**
Pore water pressure is the pressure of the water in the voids or pores of a soil #
It is an important parameter in the analysis and design of geotechnical structures because it affects the effective stress and the stability of the soil.
**Settlement** #
**Settlement**
Settlement is the vertical movement of a soil or structure due to the applicatio… #
It is an important consideration in the design of foundations, pavements, and other geotechnical structures.
**Shear Strength** #
**Shear Strength**
Shear strength is the ability of a soil or rock to withstand shear forces, which… #
It is an important parameter in the analysis and design of slopes, embankments, and other geotechnical structures.
**Slope Stability** #
**Slope Stability**
Slope stability is the ability of a slope to remain stable and resist sliding or… #
It is an important consideration in the design of slopes, embankments, and other geotechnical structures.
**Soil Classification** #
**Soil Classification**
Soil classification is the process of grouping soils based on their physical and… #
It is an important step in the analysis and design of geotechnical structures because it allows engineers to predict the behavior of the soil.
**Soil Modulus** #
**Soil Modulus**
Soil modulus is a measure of the stiffness of a soil #
It is used to predict the deformation of a soil under load. The two most common soil moduli are the Young's modulus and the shear modulus.
**Swelling** #
**Swelling**
Swelling is the increase in volume of a soil due to the absorption of water #
It is an important consideration in the design of foundations, pavements, and other geotechnical structures.
**Tension Crack** #
**Tension Crack**
A tension crack is a crack that forms in a soil or rock due to tension or pullin… #
It is an indicator of potential slope instability.
**Terzaghi's Theory** #
**Terzaghi's Theory**
Terzaghi's theory is a fundamental principle in soil mechanics that relates the… #
It states that the strength of a soil is proportional to the effective stress.
**Undrained Shear Strength** #
**Undrained Shear Strength**
Undrained shear strength is the shear strength of a soil when it is loaded quick… #
It is an important parameter in the analysis and design of quick loading or short-term conditions such as earthquakes and pile driving.
**Unconfined Compressive Strength** #
**Unconfined Compressive Strength**
Unconfined compressive strength is the maximum compressive stress that a soil ca… #
It is an important parameter in the analysis and design of foundations, retaining walls, and other geotechnical structures.
**Zone of Abrasive Wear** #
**Zone of Abrasive Wear**
Zone of abrasive wear is the area of a soil or rock that is subjected to high le… #
It is an important consideration in the design of excavation, tunneling and mining operations.
**Total Stress** #
**Total Stress**
Total stress is the sum of the effective stress and the pore water pressure on a… #
It is used to calculate the stability of slopes and the bearing capacity of foundations.
**Compaction** #
**Compaction**
Compaction is the process of increasing the density of a soil by reducing the vo… #
It is an important step in the construction of foundations, pavements, and other geotechnical structures.
**Earth Pressure Coefficient** #
**Earth Pressure Coefficient**
Earth pressure coefficient is a dimensionless factor used to calculate the horiz… #
It depends on the angle of internal friction of the soil and the angle of the backfill.
**Elasticity** #
**Elasticity**
Elasticity is the property of a material to deform under load and then return to… #
It is an important parameter in the analysis and design of geotechnical structures.
**Factor of Safety Against Sliding** #
**Factor of Safety Against Sliding**
Factor of safety against sliding is a measure of the stability of a slope #
It is defined as the ratio of the available shear strength to the required shear strength to maintain stability.
**Hydraulic Conductivity** #
**Hydraulic Conductivity**
Hydraulic conductivity is a measure of the ability of a soil or rock to conduct… #
It is an important parameter in the analysis and design of hydraulic structures such as dams, levees, and tunnels.
**Piezometric Surface** #
**Piezometric Surface**
Piezometric surface is the surface that represents the pressure head of water in… #
It is used to determine the pore water pressure and the direction of groundwater flow.
**Quick Condition** #
**Quick Condition**
Quick condition is a condition in which the pore water pressure in a soil is hig… #
It is an important consideration in the analysis and design of foundations and other geotechnical structures.
**Seepage** #
**Seepage**
Seepage is the flow of water through a soil or rock #
It is an important consideration in the analysis and design of hydraulic structures such as dams, levees, and tunnels.
**Triaxial Test** #
**Triaxial Test**
Triaxial test is a laboratory test used to determine the strength and deformatio… #
It is an important tool in the analysis and design of geotechnical structures.
**Vane Shear Test** #
**Vane Shear Test**
Vane shear test is a field test used to determine the undrained shear strength o… #
It is an important tool in the analysis and design of foundations and other geotechnical structures.
**Water Table** #
**Water Table**
Water table is the level at which the pore water pressure in a soil is equal to… #
It is an important parameter in the analysis and design of hydraulic structures such as dams, levees, and tunnels.
**Yield Stress** #
**Yield Stress**