INFLUENCE OF CONSTRUCTION TIME ON PORE PRESSURE DISSIPATION BENEATH FOUNDATIONS

During the construction of a building, excess pore pressures are induced in the underlying soil by the foundation loads and these pore pressures gradually dissipate with time. The total stresses at any point beneath the foundations will increase during the period of construction of the building until the full load is applied, and hence the pore pressures developed will depend on the rate of construction besides depending on the soil properties and elapsed time. The strength of a soil depends on the effective stresses, that is, the difference between the total stresses and the pore pressures; it thus follows that the strength of the soil will vary during the construction period and will depend on the degree of dissipation of pore pressure as well as on the total stresses. The most severe case for stability of a foundation will occur immediately after the completion of building when the full load is applied to the soil, and hence it is of interest to know what amount of dissipation will have taken place at this time and thus to know whether the bearing capacity would be controlled by the undrained soil strength, the fully drained strength, or some intermediate strength. The degree of dissipation at the end of construction is given below for various types of foundations, and the application of the results to foundation design and to loading tests is discussed briefly. /Author/

  • Corporate Authors:

    Morgan-Grampian Limited

    30 Calderwood Street
    London SE18 6QH,   England 
  • Authors:
    • LUMB, P
  • Publication Date: 1965-5

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Filing Info

  • Accession Number: 00264368
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jan 16 1975 12:00AM