Introduction Concepts & Formulas VideosSolved problemsDownload Files
Immediate settlement computationsCourses > Foundation Analysis and Design > Settlement of Shallow Foundations > Immediate settlement computations
Introduction on Immediate settlement computations :
Immediate settlement results from distortion of soil mass caused by a change in total stress. For general definitions, remarks and types of settlement refer to Settlement types, definitions, and general equation article.
Concepts and Formulas of Immediate settlement computations:
The settlement of the corner of a rectangular base of dimensions B' x L' on the surface of an elastic half-space can be computed from an equation from Theory of Elasticity as follows:
q0 = intensity of contact pressure in units of Es
B' = least lateral dimension of contributing base area in units of Si
I1 and I2 = influence factors, which depend on L'/B', thickness of stratum H. Poisson's ratio, and base embedment depth D
Es = average modulus of elasticity of soil layer
Influence factors can be computed using:
IF = embedment (or depth) factor which is equal to or less than 1.0 (for footings on the ground IF = 1.0)
- For circular footings, convert to an equivalent square.
- Determine the point where the settlement is to be computed and divide the base so the point is at the corner or common corner of one or up to 4 contributing rectangles.
- The zone of influence is either of the following:
- Depth z = 5B where B is the least total lateral dimension of base
- Depth to where a hard stratum is encountered.
- Compute zone of influence based on the actual footing dimension.
Solved sample problems of Immediate settlement computations:
Share: Follow our official Facebook page (@civilengineeringbible) and Twitter page (@CivilEngBible) and do not miss the best civil engineering tools and articles!