DESIGN OF PILES: SETTLEMENTS UNDER SERVICE LOAD, NEGATIVE FRICTION

CALCUL DES PIEUX: TASSEMENTS SOUS CHARGE DE SERVICE, FROTTEMENT NEGATIF

Experience shows that under normal behaviour (settlement under service load accompanied by negative friction) large shear stresses of the soil occur only in a very limited zone round the pile, the rest of the soil mass being subject to small deformations only. Details are given of a finite element calculation method which (1) correctly simulates soil-pile contact conditions by introducing a coulomb-type friction at the interface; (2) gives the practising engineer a rapid method of settlement evaluation. The behaviour law utilized in the calculations is linear elasticity. Calculations enable stress distribution to be calculated along the pile together with the progressive sliding of the soil along the shaft and settlement at the head of the pile. This explains the non-linear character of the load/settlement curve, the lack of coincidence of load/removal of load curves and the occurrence of residual stresses in the pile during load removal. Results are presented in the form of charts which can be used to obtain the head settlement value once the geometry of the pile studied and the soil modulus are known. In the case of negative friction, the authors study the case of a pile's head being subjected to loading, the soil on the sides of the pile being subjected to variable surcharges. The results give the evolution in stress distribution along the shaft, settlement at the head of the pile and additional stresses applied to the pile. (TRRL)

  • Corporate Authors:

    Le Batiment

    Rue Paul Valery 6
    Paris,   France 
  • Authors:
    • Boulon, M
    • Desrues, J
    • Foray, P
  • Publication Date: 1978-11

Language

  • French

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00310271
  • Record Type: Publication
  • Source Agency: Laboratoire Central des Ponts et Chausees (LCPC)
  • Files: ITRD, TRIS
  • Created Date: Oct 27 1980 12:00AM