This forum thread will track of the version history of the following download:
FOOTINGS.xls

This workbook has some concrete design in them, based on the ACI 318-99 Code in their original form. To reflect the use of the ACI 318-05, I decided to give the user the option of selecting what ACI Code is desired to be used, 318-99, 318-02, or 318-05, in those specific worksheets. Once the user selects the desired ACI Code, the appropriate "phi" factors are displayed and used. One word of caution, be careful not to mix & match "phi" factors and load factors from the various concrete codes. It's obviously up to the user to be consistent. For the purpose of just what specific concrete analysis and design is done in this workbook, the selection of either ACI 318-02 or 318-05 gives the same results.

This morning while using the "FOOTINGS.xls" workbook, one of the guys thought that he had discovered a problem/glitch because he was getting several #VALUE! errors in results cells when running a footing for a particular loading combination. He was copying a tab to create new tabs for additional loading combinations. Turns out, in editing the loads he had inadvertently used the "Space Bar" to clear or "zero-out" particular values of loadings. Problem is the program is expecting a number or a cleared/blank cell and is not expecting a "space", so it bombs.....giving a #VALUE! error message. When we cleared the contents of the cells, the problem went away, and the worksheet functioned as expected.

I have a message in many, but not all, of my spreadsheets about clearing the contents of input cells not used, and NOT to use the Space Bar to do this. This is just a reminder to you all that just to be safe, always highlight the cells to be cleared, Right-Click the mouse, and then select "Clear Contents". Of course, in most of the programs where a numerical value is expected, inputting values of 0 will also work, but usually that takes more effort and often looks too busy.

Along the same lines as the changes I made to the "RECTBEAM (318-05).xls" workbook, changes were made in the 2 table-type worksheets for actual footing design pertaining to the capacity reduction factor, "phi", for flexural tension.

In the "Footings (Table)" worksheet, the program still assumes "phi" = 0.90 for the sake of being able to calculate and suggest numbers of reinforcing bars and size of bars. I've added caution notes in the calculations as well as the "DOC" worksheet to alert the user. Most often in the design of footings the cross section will be "tension controlled", and thus the flexural tension "phi" factor will be = 0.90 anyway. This worksheet now calculates the strain in the tension reinforcing and then calculates the "phi" factor. The user can then review the results for the calculated "phi" factor to determine if it is in fact = 0.90 so that the determined reinforcing can be used. If the calculated "phi" factor is < 0.90, then the user will have to increase the footing thickness until the calculated value of "phi" = 0.90.

In the "Footings (Pier Table)" worksheet for the point on the interaction curve for pure moment (no axial load), the program now calculates the strain in the tension reinforcing, then calculates the "phi" factor, and finally calculates the ultimate moment capacity, (phi)Mn.

In the "Footings (Pier Table)" worksheet of the "FOOTINGS.xls" spreadsheet workbook, a "#REF" error (illegal cell reference) was discovered in the program logic in Column CT28. This error only showed up for a design eccentricity, ey =Mux*12/Pu, which fell between Points #8 and #9 on the interaction curve. This error was not in version 3.0 of this workbook, and I must have inadvertently created as part of the editing process in adding the calculations for determining the "phi factor" for flexural tension in version 3.1.

I have corrected this, and the updated workbook is now version 3.2.

While I was at it, I made the following couple of additional changes which hopefully are useful improvements:

In the first 2 worksheets which analyze a single footing at a time, a summary of results was added just off of the main calculation page to the right. This allows the user to quickly check the results during the process of iterating the footing dimensions, etc. in the input data, without having to take the time to either scroll down or "split-screen" the display to view the results.
I grouped all of the separate drawing components which composed the individual sketches in the worksheets into individual grouped drawing objects. This will allow the user to unprotect the worksheet, select the drawing object as a whole, and re-position it in the worksheet to make room for any additional text comments/verbiage if desired.

In the "Footings (Pier Table)" worksheet of the "FOOTINGS.xls" spreadsheet workbook (version 3.2), I ran across another "#REF" error (illegal cell reference). This was in the program logic in Column CV28. This error ONLY showed up for a design eccentricity, ey =Mux*12/Pu, which fell between Points #9 (pure moment) and #10 (pure axial tension) on the interaction curve. Like the previous update, this error was inadvertently created during the editing process in adding the calculations for determining the "phi factor" for flexural tension originating in version 3.1. I thought I had caught and covered all of this in the previous version 3.2 update, but unfortunately I missed this one.

I have corrected this, and the updated workbook is now version 3.3.