Mat Foundation Design

[accenteric]

I have been asked to design a Mat/Raft foundation for a batch plan. There are fluid storage vessels that range from 5000 to 40000 gallons. The vessels are supported upon legs onto the slab. Does anyone have any online recommended design guides or written design guides for calculation of this system? Thank you, Eric

 

[DaveAtkins]

A mat footing is simply a reinforced concrete slab on spring supports. The vessels will impose point loads on the slab.

If you have a geotechnical report, it will tell you what to assume for a spring constant. Otherwise, conservatively assume a value of 25 pci.

You need to analyze this using a program that can do finite element analysis.

DaveAtkins

 

[FixedEarth]

ACI 336 covers the structural design of combined footings and mats. Foundation Design by Teng and Foundation Analysis & Design, 4th Ed. by Bowles, covers both the geotechnical and structural aspects of mats.

If you are in granular soils that are medium dense or dense and water table is at great depth, then there no no soils issues. However, caution is needed if you are in soft to firm cohesive soils. Ask the geotechnical for differential settlement concerns.

 

[delagina]

Mat3d software =)

 

[bylar]

In NC i know of an engineer that does this frequently and too often the site is not uniform (sometimes rocks) and the whole house slopes. You should be very careful.