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The pressure exerted by soil against the wall is referred to as active pressure. The resistance offered by the soil to an object pushing against it is referred to as "passive pressure". Rankine's theory is applicable to incompressible soils. The equation for cohesionless active earth pressure is expressed as: = where:
The shear strength of soil depends on the effective stress, the drainage conditions, the density of the particles, the rate of strain, and the direction of the strain. For undrained, constant volume shearing, the Tresca theory may be used to predict the shear strength, but for drained conditions, the Mohr–Coulomb theory may be used.
The shear strength of soil is primarily due to interparticle friction and therefore, the shear resistance on a plane is approximately proportional to the effective normal stress on that plane. [3] The angle of internal friction is thus closely related to the maximum stable slope angle, often called the angle of repose.
Other advantages of the fall cone test include the alternative to estimate the undrained shear strength of a soil based on the fall cone factor K. [2] In the Fall cone test, a stainless steel cone of a standardized weight and tip angle is positioned so that its tip just touches a soil sample. The cone is released for a determined period of time ...
where is the shear strength, is the normal stress, is the intercept of the failure envelope with the axis, and is the slope of the failure envelope. The quantity c {\displaystyle c} is often called the cohesion and the angle ϕ {\displaystyle \phi } is called the angle of internal friction .
An example of lateral earth pressure overturning a retaining wall. The lateral earth pressure is the pressure that soil exerts in the horizontal direction. It is important because it affects the consolidation behavior and strength of the soil and because it is considered in the design of geotechnical engineering structures such as retaining walls, basements, tunnels, deep foundations and ...
Finally, most models separate out the effects of hydrostatic stress and shear stress, with each assumed to cause only volume change and shear change respectively. In reality, soil structure, being analogous to a "house of cards," shows both shear deformations on the application of pure compression, and volume changes on the application of pure ...
Engineers use the shear wave velocity and shear modulus to determine the soil's behavior under low-strain and vibratory loads. Additional tools such as laser-induced fluorescence , X-ray fluorescence , [ 7 ] soil conductivity / resistivity , [ 8 ] pH , temperature and membrane interface probe and cameras for capturing video imagery are also ...