This post presents an Excel User Defined Function (UDF) to carry out the analysis of vertical piles subject to horizontal loads, using the same approach as employed in the DOS program COM624. A spreadsheet including the UDF and an on-spreadsheet solution using the same method may be downloaded from LatPile.zip. As usual the file contains full open source code for the UDF and associated routines.
Detailed background information on the method of analysis is given in the COM624 manual, which can be downloaded from the link given in the previous post. An outline of the method, including all relevant equations used, is given below and in the download file, together with some simple examples.
The equations used in the analysis are shown in the screenshot below (click on any image for full size view):
On the FinDiff sheet of the download file these equations have been entered into a 25×25 matrix, which with the MINVERSE() and MMULT() functions allows the equations to be solved and the deflections calculated for any pile with 20 segments:
The same basic method of analysis has also been incorporated in a UDF, allowing the solution to be carried out much more conveniently and flexibly. Input for the UDF is shown below:
Example 1 is a 20 m long pile of uniform stiffness in a uniform soil:
Example 2 is a reinforced concrete pile with a cracking moment of 60 kNm in a soil with stiffness increasing with depth. The pile and soil stiffness values have been adjusted by hand in this case. Future versions of the program will allow input of non-linear soil and pile section stiffness.