A pile foundation is a substructure element made up of piles. The piles are responsible for transmitting the structure’s gravity loads to the subsurface. This type of deep foundation is most commonly utilized in regions where the subsoil is insufficient to sustain the weight of a home or building. The piles might be composed of … Read more
Slopes on the Earth can be natural or man-made. In the construction of highways, railways, earth dams, and river-training works, these are always required. The Geotechnical Engineer is always concerned about the slope stability because the failure would result in loss of life and property. Slope Stability : Stability of Slope is a critical factor to … Read more
The obliquity angles at the wall and on the failure plane are of opposite sign in the passive case, as opposed to the active case. In the Coulomb theory, a plane failure surface is assumed for the passive case as well, but the critical plane is the one with the lowest passive thrust. As shown … Read more
To begin, consider a simple case of active earth pressure on an inclined wall face with a uniformly sloping backfill. Backfill is made up of homogeneous, elastic, and isotropic cohesionless soil. Consider a unit length of the wall perpendicular to the plane of the paper. As shown in figure 1 below, the forces acting on … Read more
Charles Augustine Coulomb (1776), a popular French scientist and military engineer, was the first to try to put the surreal and subjective ideas about lateral earth pressure on walls that existed at the time on a scientific basis. Coulomb’s Wedge Theory considers the soil behind the wall as a whole rather than as a single … Read more
From Coulomb’s theory, Karl Culmann (1866) devised his own Culmann’s Graphical Method for calculating earth pressure. According to Coulomb’s wedge theory, Culmann’s method allows us to graphically calculate the magnitude of the earth pressure and locate the most dangerous rupture surface. This method has more general application than Poncelet’s and is, in fact, a simplified version … Read more
Pore water pressures are important factors in determining soil strength. Dimensionless coefficients called ‘Pore pressure coefficients’ or ‘Skempton’s Pore Pressure Parameters A and B’ characterize the change in pore water pressure caused by a change in applied stress. Prof. A.W. Skempton proposed these parameters, which are now universally accepted (Skempton, 1954). Pore water pressures develops … Read more
Sensitivity of Soil/ Clay : Formula, Diagram, Table The ratio of unconfined compression strength of clay in the natural or undisturbed state to that in the remoulded state, without any change in the water content is called as sensitivity of soil. A soil’s strength can be higher in its undisturbed state than in its disturbed remoulded state. … Read more
Definition and Importance of Thixotropy of Clay When flocculent clays are used in construction, they may lose strength as a result of remoulding. However, with the passage of time, the strength increases, though not to its original value. Thixotropy of clay is the process of strength loss and gain with no alteration in volume or … Read more
Shear Tests Classification Based on Drainage Conditions Before considering different methods of performing shearing strength tests on a soil, it’s important to think about the potential drainage conditions before and during the tests because they have a big impact on the results. Shearing strength can be determined in both dry and saturated conditions for a … Read more