Program Description:

"PILEGRP" is a spreadsheet program written in MS-Excel for the purpose of analysis of pile groups with rigid

caps using the "elastic method". Specifically, the properties of the pile group are calculated, and then based

upon the applied vertical and horizontal loadings, the vertical and horizontal pile reactions are calculated.

There is also a worksheet to check beam and punching shear in the pile cap for a single corner pile, for the

purpose of estimating the required pile cap thickness and subsequent pile cap weight.

This program is a workbook consisting of ten (10) worksheets, described as follows:

Program Assumptions and Limitations:

1. The Pile Group worksheets assume a minimum of 2 piles and a maximum of either 25, 75, 300, or 400 piles

for a pile group.

2. This program uses the "elastic method" of analysis, assuming that the pile cap is in fact "rigid", so that the

applied loads are linearly distributed among the piles. A common "rule-of-thumb" is to assume a pile cap

thickness equal to least 1/10 of the longest dimension (length or width) of the pile cap. All piles are assumed

to be vertical, and of equal size and length (stiffness). Battered piles are NOT permitted. The tops of all piles

are assumed at the same level.

3. This program assumes an orthogonal X-Y-Z coordinate system. All piles and piers MUST BE located in the

"positive" (1st) quadrant. "Negative" pile or pier/loading location coordinates are NOT permitted.

"Right-Hand-Rule" sign convention is used for all applied forces and moments at pier locations.

4. The piles and piers/loadings can be numbered in any desired order. However, the user should make

sure to either clear the contents of all spreadsheet cells that are not used for input or those cell values should

be input = 0. All piles and piers/loadings MUST BE input in proper numerical sequence with no "breaks" in

the numerical order of input data.

5. This program does NOT include the weight of the pile cap or piers in the calculation of the vertical pile reactions.

However, the total weight of the pile cap and piers may be included by assuming an additional "ficticious" pier

located at the centroid of the pile cap plan area, and applying the total weight at that "pier" location.

6. This program does NOT check the actual calculated pile reactions (vertical and horizontal) against known

or given allowable pile reactions for downward, uplift, or lateral cases. This is done so that the extent of any

acceptable overstress is left up to the judgement of the user. However, in all cases this must be checked by

the user.

7. This program does NOT perform all of the necessary checks for the beam-type shear or punching shear for the

pile cap, as this must be done independently by the user. However the "Corner Pile Shear" worksheet can be

used to estimate the required pile cap thickness and subsequently the pile cap weight to be accounted for.

8. This program does NOT check the flexural requirements of the pile cap, as this must be done independently by

the user.

9. This program contains numerous “comment boxes” which contain a wide variety of information including

explanations of input or output items, equations used, data tables, etc. (Note: presence of a “comment box”

is denoted by a “red triangle” in the upper right-hand corner of a cell. Merely move the mouse pointer to the

desired cell to view the contents of that particular "comment box".)