Settlement calcs for a wide load
Settlement calcs for a wide load
(OP)
I am trying to do a quick calculation for settlements using elastic settlememt formulas. Most formulas require an input for width and/or area of the footing. The load for my problem, extends more than 250 feet and similar on the length. Is there a elastic settlement formula for such loading?
Aprpeciate ur response.
Aprpeciate ur response.





RE: Settlement calcs for a wide load
RE: Settlement calcs for a wide load
RE: Settlement calcs for a wide load
RE: Settlement calcs for a wide load
RE: Settlement calcs for a wide load
Calculate the stress increase with depth (you can use any number of elastic solutions to do this.
Generate a subsurface profile of soil modulus with depth.
Integrate the stress profile and divide by the soil modulus.
Here's an example:
Let's say you have a soil layer with a modulus value of 100 tsf. Let's say the layer is 10 ft thick. Let's say the top of the layer the stress increase is 2400 psf and the stress increase at the base of the layer is 1,600 psf (i.e., the average stress increase is 1 tsf).
Let's integrate! 10 ft x 1 tsf = 10 t/ft
Let's divide! (10 t/ft)/100 tsf = 0.1 ft
That's 1.2 inches!
If you really have a "seat of settlement" that goes down 250 ft, then you have to make some assumptions and use a hyperbolic modulus model. Elastic modulus is a function of confining stress (for strain softening behavoir), so modulus values increase with depth.
Correlation from SPT to modulus is often misleading. However something like 7 to 11 N is in the range.
A dilatometer is a great tool for in-situ measuring of modulus values.
Have fun!
f-d
¡papá gordo ain't no madre flaca!