Wave analysis of mat foundations to resist differential soil movements
Johnson, Lawrence D.
Miscellaneous PaperAbstract: Soil differential movement patterns are responsible for considerable damages to all types of structures and pavements such as military facilities, commercial buildings, housing, streets, highways, parking lots, and airfields. These differential movements occur from nonuniform soil volume changes, particularly in expansive clays and collapsible silty soils, attributed to a variety of mechanisms. Among the most important mechanisms leading to volume changes are those mechanisms that change the soil water content and stress. These mechanisms include desiccation from heavy vegetation, increased soil permeability from fissures, perimeter wetting and drying from climate changes, leakage from underground utilities, and many others. This work develops a model for representing nonuniform volume changes by wave patterns of soil distortion underlying the foundation or at the ground surface. Soil-foundation distortion is measured in terms of angular distortion β which may be calculated as 4A/l where A is the amplitude and l is the wavelength of the wave pattern. The wave pattern model leads to simple methodology for rating the performance of structures subject to differential soil movement and can provide a tool to assist the design of foundations that reduce soil movement patterns. The model shows that some wavelengths are potentially more destructive than others depending on the magnitude of soil heave and the ability of the structure to tolerate soil-foundation distortion. This model may also be applicable to the analysis of pavements. NOTE: This file is large. Allow your browser several minutes to download the file.
Geotechnical Laboratory (U.S.)Engineer Research and Development Center (U.S.)
Angular distortion; Differential movement; Expansive soil; Floor tolerance; Foundation performance; Potential heave; Soil-structure interaction; Foundations; Swelling soils; Soil mechanics; Mathematical models; Numerical models
Miscellaneous paper (U.S. Army Engineer Waterways Experiment Station) ; GL-91-7.
Approved for public release; distribution is unlimited.