“WALLPRES” – WALL PRESSURE ANALYSIS
Program Description:
“WALLPRES” is a spreadsheet program written in MS-Excel for the purpose of determining the horizontal (lateral) pressures to be applied to walls from various types of loading including lateral earth pressure, hydrostatic pressure, as well as uniform, point, line, and strip surcharge loadings.
This program is a workbook consisting of five (5) worksheets, described as follows:
Doc – documentation sheet
Wall Soil Pressures – Static horizontal soil pressure against wall
Wall Pressures from Point Load – Horizontal pressures on rigid wall from point surcharge load
Wall Pressures from Line Load – Horizontal pressures on rigid wall from continuous strip surcharge load
Wall Pressures from Strip Load – Horizontal pressures on rigid wall from continuous line surcharge load
Program Assumptions and Limitations:
1. This program is based on the following references:
a. NAVFAC DM-7.02 Manual – “Foundations & Earth Structures” (1986)
b. NAVFAC DM-7.01 Manual – “Soil Mechanics” (1986)
c. Army TM 5-818-1 / Air Force AFM 88-3, Chap. 7 (Oct. 1983) “Soils and Geology Procedures for Foundation Design of Buildings and Other Structures”
d. “Foundation Analysis and Design” (2nd Edition), by: Joseph E. Bowles McGraw-Hill, 1977
e. “USS Steel Sheet Piling Design Manual” – updated and reprinted by FHWA with permission (July 1984)
f. “Lateral Soil Pressure on Retaining Walls and Embedded Exterior Walls of Structures” Report U7-PROJ-S-RPT-STRU-6001, by: Sargent & Lundy, LLC (Feb. 26, 2009) for South Texas Project Units 3 & 4, Project No.: 12462-003
2. The resulting pressures obtained from the worksheets in this workbook can be used in the design of the stems of either cantilever or propped cantilever retaining walls, as well as for long walls of tanks and pits.
3. The equations used in the “Wall Pressures from Point Load” and “Wall Pressures from Line Load” worksheets are from References “a” through “e” above, utilizing original (1885) Boussinesq Equations modified to correlate with experimental test results. The Boussinesq equations assume the that wall is rigid and does not move, and that the wall is perfectly smooth (no shear stress between wall and soil). Thus, the equations overestimate the wall pressures for flexible walls by up to a factor of 2.
4. The equation used in the “Wall Pressures from Strip Load” worksheet is from References “d” and “e” above. Again, this equation assumes that the wall is rigid (does not move), which overestimates the wall pressures for flexible walls by up to a factor of 2. Thus, the factor of 2 appears in the numerator of this version of the equation. Other references may cite this equation without the factor of 2, which would normally be more applicable for flexible walls which are able to move at top.
5. This program contains “comment boxes” which contain information including explanations of input items, 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”.)
