CALCULATION OF THE LATERAL FRICTION OF DRIVEN PILES

BEREKENING VAN DE MANTELWRIJVING OP INGEHEIDE PALEN

THE AUTHOR DEALS WITH BOTH NEGATIVE AND POSITIVE FRICTIONS. THE FIRST PART OF THE ARTICLE PRESENTS AN ANALYSIS OF THE ZEEVAERT METHOD. ZEEVAERT ESTIMATES THAT THE ZONE DISTURBED BY DRIVING IS 1,4 TIMES THE RADIUS OF PILE MEASURED FROM ITS AXIS, AND THAT THE MINIMUM SHEAR STRENGTH IS LOCATED AT 1,05 TIMES THIS RADIUS AND IS DETERMINED BY THE FRICTION ANGLE OF THE DISTURBED SOIL. FORMULAE ARE PRESENTED FOR CALCULATING THE RECONSOLIDATION TIME. ZEEVAERT USES TWO DIFFERENT METHODS. THE FIRST (CALLED THE OVERALL METHOD) ASSUMES (1) A PARABOLIC DISTRIBUTION OF THE FINAL EFFECTIVE STRESSES AND (2) A GIVEN VALUE OF THE EQUIVALENT SURFACE OF INFLUENCE, WHICH WOULD BE SOLELY A FUNCTION OF THE PILE DIAMETER. THE SECOND METHOD, E.G. THE ITERATION METHOD, IS BASED ON AN EQUIVALENT SURFACE OF INFLUENCE WHICH IS A FUNCTION OF DEPTH. TO DETERMINE THIS EQUIVALENT SURFACE, IT IS NECESSARY TO USE A LAW OF SHEAR STRESS DISTRIBUTION ALONG THE SHAFT OF THE PILE. THE SECOND PART OF THE DOCUMENT DESCRIBES HOW IT IS POSSIBLE TO DETERMINE THE EQUIVALENT SURFACE AND THE NEGATIVE FRICTION IN THE CASE OF SUCCESSIVE LAYERS. THE METHOD IS EXTENDED TO THE CALCULATION OF POSITIVE FRICTION IN THE CASE OF, FIRST, A SINGLE HOMOGENEOUS LAYER, THEN OF A NUMBER OF LAYERS. IT IS SHOWN HOW TO TAKE INTO ACCOUNT A POSSIBLE ADHESION BETWEEN THE SOIL AND THE PILE IN THE CASE OF NEGATIVE AND POSITIVE FRICTION. PART 3 CONSIDERS THE NUMERICAL APPLICATION OF THE DIFFERENT METHODS TO CONCRETE CASES. TWO EXAMPLES ILLUSTRATE THE FORECAST OF NEGATIVE FRICTION, A THIRD ENVISAGES POSITIVE FRICTION. IN THE CASE OF NEGATIVE FRICTION IN THE FIRST EXAMPLE THE ZEEVAERT ITERATION METHOD WAS USED. FOR THE SECOND EXAMPLE OF NEGATIVE FRICTION THE ZEEVAERT OVERALL METHOD WAS UTILIZED. FOR THE POSITIVE FRICTION, THE SUCCESSIVE METHODS WERE EMPLOYED: THE OVERALL ZEEVAERT METHOD BASED ON A LINEAR DISTRIBUTION OF THE FINAL STRESSES, THE OVERALL METHOD BASED ON A PARABOLIC DISTRIBUTION, THE ITERATION METHOD, AND AN ORIGINAL METHOD. PART 4 PRESENTS A CRITICAL ANALYSIS OF THE METHODS DESCRIBED.

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  • Dutch

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  • Accession Number: 01302482
  • Record Type: Publication
  • Source Agency: Institut Francais des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)
  • Files: ITRD
  • Created Date: Nov 21 2010 8:41AM