ANALYSIS OF STRIP FOOTINGS ON EXPANSIVE SOILS

A simplified form of boundary element analysis is outlined in which the interaction between a strip footing and a swelling or shrinking soil is considered. The "free-field" soil movements (those which would occur if the strip were not present) are assumed to be known and are represented by a parabolic distribution along the length of the strip. The soil is represented by an elastic continuum, but it is shown that the precise form of the soil model has relatively little influence on the strip behaviour, and that a subgrade reaction model of soil behaviour would be adequate. Allowance is made for the possibility of local bearing failure by specifying limiting pressures (which may be different for tension and compression) along the strip. A series of parametric solutions is presented in dimensionless form for the bending moments and movements along a strip. As would be expected, increased strip stiffness leads to larger moments and smaller differential settlements within the strip. The occurrence of local bearing failure generally leads to smaller bending moments and differential settlements than for an elastic soil, and correction factors are presented for this effect. The effects of non-uniform soil strength and modulus along the strip, and of the strip "lifting-off" the soil, are also examined. (Author/TRRL)

• Corporate Authors:

  University of Sydney

  School of Civil and Mining Engineering, Parramatta Road
  Sydney, New South Wales 2006,   Australia 
• Authors:
  • POULOS, H G
• Publication Date: 1983-9

Media Info

• Features: Figures; References; Tables;
• Pagination: 34 p.
• Serial:
  • Issue Number: R456

Subject/Index Terms

• TRT Terms: Bearing capacity; Bending moments; Boundary value problems; Deflection; Differential settlement; Engineering moments; Failure; Foundations; Ground settlement; Mat foundations; Mathematical analysis; Mathematical models; Modulus; Motion; Soil mechanics; Stiffness; Strength of materials; Strip footings; Structural analysis; Swelling soils; Torque
• Uncontrolled Terms: Boundary conditions; Models
• Old TRIS Terms: Soil behavior
• ITRD Terms: 6471: Analysis (math); 5586: Deflection; 5520: Failure; 5410: Moment (force); 5483: Movement; 5792: Settlement; 3397: Shallow foundation; 5931: Stiffness; 5203: Swelling (soil)
• Subject Areas: Geotechnology; Highways;

Filing Info

• Accession Number: 00389225
• Record Type: Publication
• Source Agency: ARRB
• Report/Paper Numbers: Monograph
• Files: ITRD, TRIS, ATRI
• Created Date: Nov 30 1984 12:00AM