Mat Foundations

[cookyb]

I have a 2-story building with basement on soft soils up to 50 ft deep and need to design a mat slab to support it. Can anyone recommend some software to assist with this?

Thanks!

 

[structuresguy]

I use Staad Foundation now for mat slab design. Until recently, I have used Staad Pro and/or Mat3D.

I prefer Staad Foundation over the other two. It is similar to Staad Pro, in that it is based on finite element analysis, and you can see stress, bending moment, bearing pressure distribution diagrams across your mat. But Staad Foundation is made specifically for foundations, so it also does punching shear checks, and can also be used for pile supported mats.

Mat3D is generally pretty good for mat design, and I have used it many times, but it has several limitations I don't like. You can not see any stress or bearing distribution diagrams. So if it says you are overstressing the soil bearing, you have no idea where the problem is. And the biggest limitation is that it only works for rectangular shaped mats. Not odd shapes allowed, which is why i have moved on to Staad Foundation. In some ways, I like Mat3D better. Data entry is quicker I think. But reinforcing design uses average over the entire mat, so no reinforcing zones.

 

[ishvaaag]

With the problem of some degree of opacity in the results (you need delve a bit into the program to get these), CYPECAD can deal with mat slabs of any shape. Uses a modulus of subgrade reaction approach, and provides directly reinforcement in flexure and shear for a number of codes. Very proven, since used almost with generality all over Spain (leader structural design package here).

 

[cookyb]

Thanks for your help, guys. My foundation will have a few jogs in it so it sounds like Mat3D is out. I like being able to have reinforcing zones as well.

I know that Staad Foundation is a stand alone module, what about CYPECAD?

Thanks again.

 

[ishvaaag]

CYPECAD is the main package in the CYPE set. Uses to be offered with the full package at almost no increase over the full set for the first year. You buy it with optional yearly updates. Since I have used it extensively over 4 years I can say that

Input of data is great.

You get some line dwgs of your floors in one or various archives and import it as a background template for the construction of the 3D model.

Calculation side of the thing is adequate but don't expect it be the state of the art of it.

Calculation output, maybe the weakest part because it was intended for the following point, so remains a bit "black box" and opaque. This not troublesome if the asking party is tolerant but a nuisance for those accustomed to know how everything is derived. This is a problem with a lot of calculation programs and with the likes of these, a bit more.

Structural drawings. Cypecad excels in easy entry and good structural drawings output, specially plans of floors and mats, columns and shear cores and beams details. The whole design is available one or another way.

For practice in Spain is almost a must since the industry is so sortsighted that has decided to put all the eggs in a basket and there are even reinforcing steel fabricators that brumble if you give them any other thing.