A finite difference solution for 1-D soil consolidation using Excel

Abstract

Terzaghi's one-dimensional (1-D) soil consolidation equation is solved using a finite difference (FD) method and Microsoft's Excel spreadsheet. Spreadsheets are inexpensive computational tools that are readily available to students and practicing engineers. They are relatively easy to use and, in many instances, have replaced calculators. Spreadsheets can perform the complex calculations associated with design problems in any engineering discipline. They are an ideal computational tool for engineering design work, an inherently iterative process, where strings of interrelated mathematical expressions are reevaluated every time a problem parameter, such as a length, is changed. For spreadsheet calculations, all the fundamental mathematical operations are available and most also include a suite of intrinsic functions accommodating operations involving logic, statistics, calendars, finances, etc. Of all the spreadsheet features available, the ability to create and run user developed programs may be the most overlooked but powerful resource. Using Microsoft's Visual Basic Applications (VBA) development tool in Excel, a user can write/run analysis routines of their own making within a spreadsheet. This powerful feature is demonstrated using the FD method and a 1-D soil consolidation problem.