Settlement and Allowable Bearing Capacity in the soil under shallow foundation "article"

the allowable settlement of shallow foundations may control the allowable bearing capacity.The
allowable settlement itself may be controlled by local building codes.

For example; the maximum  allowable settlement for mat foundation is 50 mm, and 25 mm for isolated footing.These foundations should be designed for these limiting values of settlement (by calculating the allowable bearing capacity from the allowable settlement). thus, the allowable bearing capacity is the smaller of the following two conditions:

The settlement of a foundation can be divided into two major

categories:

a)  Immediate or elastic settlement (Se):

Elastic or immediate settlement occurs during or immediately after the application of the load
 (construction of structure) without change in the moisture content of the soil.


b)  Consolidation Settlement (Sc) :

Consolidation settlement occur over time, such that pore water is extruded from the void spaces of saturated clayey soil submerged in water.Consolidation settlement comprises two phases: Primary and secondary. To calculate foundation settlement  (both elastic and consolidation), it is required to estimate the vertical stress increase in the soil mass due to the net load applied on the foundation .