Definition:
Geotechnical engineering is the branch of civil engineering concerned with the engineering behavior of earth materials.
Branch of civil engineering :
In geotechnical engineering, soils are considered a three-phase material composed of: rock or minerals particles, water and air. The voids of a soil, the spaces in between mineral particles, contain the water and air.
The engineering properties of soils are affected by four main factors: the predominant size of the mineral particles, the type of mineral particles, the grain size distribution, and the relative quantities of mineral, water and air present in the soil matrix. Fine particles (fines) are defined as particles less than 0.075 mm in diameter.
Unit Weight
Total unit weight: Cumulative weight of the solid particles, water and air in the material per unit volume. Note that the air phase is often assumed to be weightless.
Porosity
Ratio of the volume of voids (containing air, water, or other fluids) in a soil to the total volume of the soil. A porosity of 0 implies that there are no voids in the soil.
Void ratio
is the ratio of the volume of voids to the volume of solid particles in a soil. Void ratio is mathematically related to the porosity.
Permeability
A measure of the ability of water to flow through the soil, expressed in units of velocity.
Compressibility
The rate of change of volume with effective stress. If the pores are filled with water, then the water must be squeezed out of the pores to allow volumetric compression of the soil; this process is called consolidation.
Shear strength
The shear stress that will cause shear failure.
Atterberg Limits
Liquid limit, plastic limit, and shrinkage limit. These indices are used for estimation of other engineering properties and for soil classification.
Geotechnical engineering is the branch of civil engineering concerned with the engineering behavior of earth materials.
Branch of civil engineering :
History:
Several foundation-related engineering problems, such as the Leaning Tower of Pisa, prompted scientists to begin taking a more scientific-based approach to examining the subsurface. The earliest advances occurred in the development of earth pressure theories for the construction of retaining walls. Henri Gautier, a French Royal Engineer, recognized the "natural slope" of different soils in 1717, an idea later known as the soil's Angle of repose. A rudimentary soil classification system was also developed based on a material's unit weight, which is no longer considered a good indication of soil type.In geotechnical engineering, soils are considered a three-phase material composed of: rock or minerals particles, water and air. The voids of a soil, the spaces in between mineral particles, contain the water and air.
The engineering properties of soils are affected by four main factors: the predominant size of the mineral particles, the type of mineral particles, the grain size distribution, and the relative quantities of mineral, water and air present in the soil matrix. Fine particles (fines) are defined as particles less than 0.075 mm in diameter.
Soil properties
Some of the important properties of soils that are used by geotechnical engineers to analyze site conditions and design earthworks, retaining structures, and foundations are:Unit Weight
Total unit weight: Cumulative weight of the solid particles, water and air in the material per unit volume. Note that the air phase is often assumed to be weightless.
Porosity
Ratio of the volume of voids (containing air, water, or other fluids) in a soil to the total volume of the soil. A porosity of 0 implies that there are no voids in the soil.
Void ratio
is the ratio of the volume of voids to the volume of solid particles in a soil. Void ratio is mathematically related to the porosity.
Permeability
A measure of the ability of water to flow through the soil, expressed in units of velocity.
Compressibility
The rate of change of volume with effective stress. If the pores are filled with water, then the water must be squeezed out of the pores to allow volumetric compression of the soil; this process is called consolidation.
Shear strength
The shear stress that will cause shear failure.
Atterberg Limits
Liquid limit, plastic limit, and shrinkage limit. These indices are used for estimation of other engineering properties and for soil classification.
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