Enercal Beam on Elastic 1

[xkcstructural]

Hey Just doing a quick check, I read some other threads on beam on elastic for enercalc and how it is applied.

But the didnt seem to answer the question I have, is when is it appropriate to use beam on elastic? I read some people use it to model a 1' strip and in the manual i read it only works under compression loads.

Does any one here have a good deep understanding on its applicability?

Currently, Ive seen it used in a bearing situation where, you run a 30' long wall and footing scenario and check the bearing is okay, this is only done when a quick spreadsheet says that the bearing is failing under new/changed loading.

 

[KootK]

At a high level, I would say that beam on elastic is applicable when:

1) The thing being assumed to be elastic:

a) actually is elastic or;

b) is elastic enough that its inelasticity doesn't invalidate the design.

2) The stiffness of the thing being assumed to be elastic:

a) Is known accurately or, more likely in the case of foundations;

b) Can be bounded by extreme values that would bracket the real behavior suitably.

3) The connection between the beam and the elastic substrate either:

a) Can resist tension (not shallow foundations) or;

b) Is never required to resist tension.

 

[CConrad]

The Beam on Elastic Foundation module in ENERCALC SEL was developed with long wall footings in mind. It was conceived as a method of considering the interaction of soil compressibility and member stiffness. It wasn't intended to be applied to conditions where any portion of the footing tends to lose contact with the soil under any load conditions.

From the relevant section of the user's manual:

Note: This module will stop if it finds any locations where the soil springs tend to go into tension, so be sure to use realistic load combinations. For instance, don't run +W Only or +Lr Only, without the corresponding dead load that would also be applied concurrently. Also be careful when allowing automatic reversals of wind or seismic loads that could result in net tension at the soil interface.



Director of Engineering
ENERCALC, LLC
Web:

http://www.enercalc.com

 

[Denial]

This probably won't be of any direct help to you, but my website (

https://rmniall.com)

has a downloadable, directly executable program to analyse beams on elastic foundations, and it allows for the upwards-movement foundation constant to be different from the downwards=movement constant.

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