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Geotechnical Engineering Glossary

25 essential terms — because precise language is the foundation of clear thinking in Geotechnical Engineering.

Showing 25 of 25 terms

Moisture content boundaries that define the transitions between solid, semi-solid, plastic, and liquid states of fine-grained soil.

Related:liquid limitplastic limitplasticity index

The maximum load per unit area that a soil can support without undergoing shear failure beneath a foundation.

Related:foundation designshear strengthfactor of safety

The mechanical process of increasing soil density by reducing air voids through applied energy.

Related:Proctor testdry densityoptimum moisture content

A continuous in-situ test measuring cone tip resistance and sleeve friction as an instrumented probe is pushed into the ground.

Related:tip resistancesleeve frictionsoil profiling

The gradual reduction in volume of saturated fine-grained soil due to drainage of pore water under sustained loading.

Related:settlementpore water pressurevoid ratio

The portion of total stress transmitted through grain-to-grain contacts in soil, equal to total stress minus pore water pressure.

Related:pore water pressuretotal stressconsolidation

The ratio of available resisting forces (or strength) to driving forces (or applied stress), used to quantify the margin of stability in geotechnical design.

Related:slope stabilitybearing capacitydesign criteria

A graphical network of flow lines and equipotential lines used to solve two-dimensional steady-state seepage problems.

Related:seepageDarcy's lawequipotential line

Synthetic polymeric materials (geotextiles, geogrids, geomembranes) used in geotechnical applications for reinforcement, filtration, drainage, and separation.

Related:geotextilegeogridsoil reinforcement

Engineering techniques used to enhance the mechanical properties of weak or problematic soils, including compaction, grouting, and reinforcement.

Related:vibro-compactionstone columnspreloading

The horizontal stress exerted by soil on a retaining structure, classified as active, passive, or at-rest depending on wall movement.

Related:retaining wallRankine theoryCoulomb theory

The loss of strength and stiffness in loose, saturated granular soil during cyclic loading, causing it to behave as a viscous fluid.

Related:earthquakepore water pressuresand

A graphical representation of the state of stress at a point, showing normal and shear stresses on planes at all orientations. Used with the Mohr-Coulomb criterion to assess failure.

Related:shear strengthprincipal stressfailure envelope

The ratio of the maximum past effective stress to the current effective stress, indicating the stress history of a clay deposit.

Related:preconsolidation pressurenormally consolidatedoverconsolidated

A measure of how easily water can flow through soil voids, quantified as hydraulic conductivity (k) in Darcy's law.

Related:Darcy's lawseepagehydraulic gradient

A deep foundation element that transfers structural loads to competent soil or rock at depth through end bearing and shaft friction.

Related:deep foundationend bearingskin friction

The pressure of groundwater held within soil voids, which reduces effective stress and influences soil strength and stability.

Related:effective stressexcess pore pressuregroundwater

A structure designed to resist lateral earth pressure and retain soil at different elevations on either side.

Related:lateral earth pressurecantilever wallMSE wall

The movement of water through soil pores driven by hydraulic gradient, governed by Darcy's law.

Related:permeabilityflow nethydraulic gradient

The downward movement of a structure's foundation due to compression of underlying soil, comprising immediate, consolidation, and secondary compression components.

Related:consolidationelastic settlementdifferential settlement

The maximum shear stress a soil can resist before failure, typically described by the Mohr-Coulomb criterion using cohesion and friction angle.

Related:cohesionfriction angletriaxial test

The analysis of the potential for soil or rock slopes to fail by sliding along a critical surface.

Related:factor of safetylimit equilibriumlandslide

The systematic grouping of soils based on physical properties such as grain size, plasticity, and organic content using systems like USCS or AASHTO.

Related:USCSgrain sizeAtterberg limits

An in-situ test that measures soil resistance to penetration by counting hammer blows (N-value) to drive a sampler a standard distance.

Related:N-valueblow countsoil investigation

The ratio of the volume of voids to the volume of solids in a soil mass, denoted as e. A key index property for characterizing soil state.

Related:porositydry densitycompressibility
Geotechnical Engineering Glossary - Key Terms & Definitions | PiqCue