Finite Element Analysis 1

[teckert]

If i were to do a finite element analysis of a retaining wall- would create plate elements for the concrete wall?

What would i use for the reinforcement bars?

I am going to use an interface elements to account for soil structure interaction.

Thanks,

 

[IDS]

It depends what you are wanting to get out of the analysis.

If you are wanting to model the soil-structure interaction and get bending moments and shear forces for use in the reinforced concrete design then you don't need to model the reinforcement. In fact you could use beam elements with offset elements at each node, rather than plate elements.

If you need to do a rigorous analysis of the concrete behaviour for some reason it gets more complicated. You could use beam elements for the reinforcement, but you will have to think about how you will model the concrete behaviour after cracking, bond slip between the concrete and the bars, etc.

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[Qshake]

I would not waste time with a FEA of a retaining wall.

Such an analysis is trivial and can be done faster by using one of the many text references of retaining wall design for different loadings and or software for retaining walls.

If I were to encourage anyone to study FEA of concrete elements or soil-structure interaction, there are many references available through ACI for concrete and ASCE Journal of Geotechnical Engineering for soil structure interaction. I do place a greater emphasis on understanding what you are doing before you start putting numbers in a program or chosing elements willy-nilly without thinking of what you intend to get out of the anlaysis.



Regards,
Qshake

Eng-Tips Forums:Real Solutions for Real Problems Really Quick.

 

[IDS]

Such an analysis is trivial and can be done faster by using one of the many text references of retaining wall design for different loadings and or software for retaining walls.

Whilst it is true that a typical retaining wall analysis can be done without FEA (or any other software for that matter), it is also true that there are many situations where a FEA (if done properly) will give you a much better picture of what is really happening than a traditional simplified calculation.

Not knowing what the intended purpose is, I wouldn't dismiss all FEA of retaining walls as a waste of time.

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[Qshake]

Laterial earth pressure and Retaining wall analysis has been under development since the 1700s and many closed form solutions exist as well as many empirical solutions which have been found to be in line with testing.

I do not think FEA is a waste of time I just think that there are other resources to investigate to understand what is required when using FEA in such an endeavor. I do not begrudge the FEA user or retaining wall designer who, with years of experience, is developing a parametric study of such structures.

Like any FEA in the hands of a novice, it can have severe adverse consequences. Lives and potentially millions of dollars of improvements or damanges are at stake. And all because one decided to discard the tried and tested methods of analysis to design such a structure.

Regards,
Qshake

Eng-Tips Forums:Real Solutions for Real Problems Really Quick.