Here's an update to the "FOOTINGS.xls" workbook which now includes 2 new worksheets, one for a rigid footing analysis with up to 16 piers/load points, and the other to analyze a rigid, unsymmetrical footing base. The names of the 2 new worksheet tabs are "Footing (16 net pier loads)" and "Unsymmetrical Footing Base".

The "Footing (16 net pier loads)" worksheet should help particularly with bearing pressure and stability analysis for equipment foundations involving several piers/pedestals and short walls all on a common rigid foundation. The "Unsymmetrical Footing Base" worksheet should help with analysis of maximum soil pressure for situations where a non-rectangular shaped rigid footing base has to be used.

The current version is now 3.4.

While in and using the "FOOTINGS.xls" workbook recently, I discovered that there were several comment boxes that at some point have gotten shrunk down to where all of the text was not visible. I went through the entire workbook and made the adjustments to the sizes of the comment boxes where required.

While I was at it, I decided to update both the "Footings (Table)" and "Footings (Pier Table)" worksheets to be applicable for ACI 318 Codes, now up through the ACI 318-11 Code version. As best that I could tell, there have been no real changes to the ACI 318 Code (methodology, phi factors, etc.) , at least as far as flexure, shear, compression, and bearing are concerned, since the 2002 version. So it was a relatively easy modification to get those two worksheets updated.

This workbook is now version 3.5.

In the "Footings (Table)" worksheet of the "FOOTINGS.xls", it was discovered that original intended criteria for use of top reinforcing was not being handled for all cases. I had originally set the criteria for the use of top reinforcing in the footing base to be for either the case with uplift load on the footing pier and/or for the case when there is no soil cover (D = 0) over the top of the footing. The worksheet was providing top reinforcing when an uplift load was input. However, for the special case of no uplift load along with no soil cover, the worksheet was showing the top reinforcing = 0, when there should have been a calculated value > 0.

I have made the necessary corrections.

This workbook is now version 3.6.