Soil mechanics and engineering properties — Glossary · Advanced Certificate in Engineering Geology and Soil Mechanics

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Advanced Certificate in Engineering Geology and Soil Mechanics #

An educational program that provides students with an in-depth understanding of the principles and practices of engineering geology and soil mechanics. Students learn about the behavior of soil and rock materials under various conditions and how to apply this knowledge to engineering projects.

Angle of Internal Friction #

The angle at which a soil mass can remain stable before it starts to slide. It is a critical parameter in soil mechanics as it determines the shear strength of the soil. The greater the angle of internal friction, the more stable the soil mass.

Atterberg Limits #

A set of tests used to determine the water content at which a soil transitions from one state to another. The Atterberg limits consist of the liquid limit, plastic limit, and shrinkage limit, which are used to classify soils based on their plasticity.

Axis #

In soil mechanics, the term axis refers to a line around which a soil body is symmetrically loaded. Understanding the axis of loading is crucial for determining the stress distribution within a soil mass.

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B

Bearing Capacity #

The maximum load that a soil can support without undergoing excessive settlement or shear failure. Bearing capacity is a critical consideration in the design of foundations to ensure the stability and safety of structures.

Boussinesq's Theory #

A theory in soil mechanics that describes the distribution of stress in a semi-infinite elastic medium due to a concentrated load applied at the surface. Boussinesq's theory is used to analyze the stresses induced by foundations on soils.

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C

Compaction #

The process of increasing the density of soil by applying mechanical energy to reduce voids and improve load-bearing capacity. Compaction is commonly used in construction to ensure the stability of foundations and embankments.

Consolidation #

The process by which soil particles rearrange themselves under a load, causing the soil mass to settle and reduce in volume. Consolidation is a time-dependent phenomenon that can lead to long-term settlement of structures built on compressible soils.

Consolidation Test #

A laboratory test used to determine the consolidation properties of soil, including the coefficient of consolidation and the compression index. The data obtained from a consolidation test is essential for predicting the settlement behavior of soils.

Critical State Soil Mechanics #

A framework in soil mechanics that describes the behavior of soils at their critical state, where the soil reaches a unique state of stress and strain independent of its loading history. Critical state soil mechanics is used to analyze the shear strength and deformation characteristics of soils.

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Deformation #

The change in shape or volume of a soil mass under applied loads. Deformation in soils can be elastic, where the soil returns to its original shape after the load is removed, or plastic, where the soil undergoes permanent deformation.

Direct Shear Test #

A laboratory test used to determine the shear strength of soils by applying a direct shear force to a soil sample. The results of a direct shear test are used to calculate parameters such as the cohesion and angle of internal friction of the soil.

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Elasticity #

The property of a material to deform under stress and return to its original shape when the stress is removed. In soil mechanics, understanding the elasticity of soils is crucial for predicting their behavior under different loading conditions.

Engineering Properties #

The physical and mechanical characteristics of soils that affect their behavior in engineering applications. Engineering properties include parameters such as grain size, density, permeability, shear strength, and compressibility, which are essential for designing and constructing structures on soil.

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Foundation #

The substructure of a building or structure that transfers the load from the superstructure to the underlying soil or rock. Foundations are designed to distribute the load evenly to prevent settlement and ensure the stability of the structure.

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Geotechnical Engineering #

A branch of civil engineering that deals with the behavior of soil and rock materials in relation to the design and construction of foundations, slopes, embankments, tunnels, and other geotechnical structures. Geotechnical engineering encompasses soil mechanics, foundation engineering, and geology.

Grain Size #

The size and distribution of particles in a soil sample, ranging from clay particles (less than 0.002 mm) to sand particles (0.05 mm to 2 mm) to gravel particles (2 mm to 75 mm). Grain size is a critical parameter in soil mechanics as it influences the permeability, compaction, and shear strength of soils.

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Hydraulic Conductivity #

The ability of a soil to transmit water under a hydraulic gradient. Hydraulic conductivity is a measure of the permeability of soils and is crucial for understanding groundwater flow, seepage, and drainage in geotechnical engineering.

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Index Properties #

The basic physical properties of soil that are used to classify and describe its behavior. Index properties include grain size distribution, moisture content, specific gravity, Atterberg limits, and compaction characteristics, which are essential for characterizing soils in geotechnical investigations.

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Lateral Earth Pressure #

The pressure exerted by soil against a retaining structure, such as a wall or foundation, due to the lateral movement of the soil mass. Understanding lateral earth pressure is crucial for designing stable retaining walls and excavation support systems.

Liquid Limit #

The water content at which a soil transitions from a plastic to a liquid state and begins to flow. The liquid limit is determined using the Casagrande method and is one of the Atterberg limits used to classify soils based on their plasticity.

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Mohr #

Coulomb Failure Criterion: A mathematical model used to describe the shear strength of soils based on the principle of effective stress. The Mohr-Coulomb failure criterion relates the shear strength of soils to the normal stress and the angle of internal friction, providing a basis for analyzing soil stability and slope stability.

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Overconsolidation #

A condition in which a soil has been subjected to higher pressures in the past, causing it to be more compacted and have lower void ratios than expected under the current stress conditions. Overconsolidation affects the consolidation behavior and shear strength of soils.

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Permeability #

The ability of a soil to allow water to flow through it under a hydraulic gradient. Permeability is a critical property of soils that influences groundwater flow, seepage, and drainage in geotechnical engineering projects.

Plastic Limit #

The water content at which a soil transitions from a semisolid plastic state to a solid state and crumbles when rolled into threads. The plastic limit is one of the Atterberg limits used to classify soils based on their plasticity and is important for understanding the behavior of cohesive soils.

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Q

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R

Resilient Modulus #

A measure of the stiffness and elastic behavior of a soil under repeated loading. The resilient modulus is used to characterize the structural properties of soils and is essential for pavement design and analysis.

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S

Settlement #

The downward movement of a structure or soil mass due to the compression and consolidation of the underlying soil. Settlement can occur immediately after construction (immediate settlement) or over time as the soil continues to consolidate (long-term settlement).

Shear Strength #

The ability of a soil to resist shear stresses and maintain its stability under loading. Shear strength is a critical parameter in soil mechanics that determines the stability of slopes, foundations, and retaining structures.

Specific Gravity #

The ratio of the density of a soil or rock material to the density of water. Specific gravity is a fundamental property of soils that influences their weight, porosity, and buoyancy, and is used to classify and characterize soils in geotechnical engineering.

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Triaxial Test #

A laboratory test used to determine the stress-strain behavior and shear strength of soils under different confining pressures. The triaxial test is essential for analyzing the strength and deformation characteristics of soils under various loading conditions.

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Void Ratio #

The ratio of the volume of voids in a soil mass to the volume of solids. Void ratio is a critical parameter in soil mechanics that influences the compaction, permeability, and shear strength of soils, and is used to classify soils based on their particle packing.

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Water Content #

The amount of water present in a soil sample expressed as a percentage of the total weight of the soil. Water content is a fundamental property of soils that influences their engineering behavior, including strength, permeability, and compressibility.

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Zero Air Voids Line #

A line on a plot of void ratio versus effective stress that represents the condition where a soil sample has zero air voids. The zero air voids line is used to determine the critical state of soils and their behavior under different stress conditions in soil mechanics.