Foundation-Shallow Foundation Capacity in Undrained Soil

In undrained soil, the bearing capacity of shallow foundations is dependent on the undrained cohesion of soil.

For the condition where footing is surrounded by surcharge pressure at surface level, the bearing capacity factor can be taken as 5.14.

For embedded footing, the weight of soil above the founding plane exerts surcharge pressure on that plane.

There are various methods to determine the shape factor and bearing capacity factor of a shallow foundation.

Skempton’s chart presents the values to be adopted based on the footing shape i.e. circle, square and strip.

For footing with custom aspect ratio, equations after Salgado et al and Eurocode 7 may be used.