THE BEHAVIOUR OF DEAD ANCHORS SUBJECTED TO REPEATED AND ALTERNATING LOADS

Ground anchors essentially comprise a high strength tendon which is fixed in the ground by means of grout, and in general they are used to resist pull-out forces such as occur with transmission towers, dry dock floors such as tied-back retaining walls. The authors discuss the effect of prestressing such anchors to stiffen the system, and suggest that in the past little or no attention has been given to the effects of repeated loading of both prestressed and dead (zero prestress) anchors. This paper presents the results of a study into static loading effects related to the repeated loading of foundations - in such cases inertia forces are very small and therefore negligible. A review of previous relevant work is presented. The test equipment illustrated and described consisted of six identical test rigs constructed to fulfil the basic requirements of (1) that any sand density could be achieved, (2) that any sand stress history could be maintained, (3) that the plate-shape anchors used could be subjected to both uplift and compressive loading in a cycle of loading if necessary, and (4) that very small changes in load could be applied. Information is provided on the materials used, and the test sequences adopted, and the results of static load tests and repeated load tests are presented in graphical form and discussed. It is suggested that despite limitations inherent in the tests, trends and conclusions can be drawn from the results. First, dead anchors when subjected to load repetitions sustain non-recoverable movements, the movement per cycle of load decreasing with the number of loadings. A family of curves exist for a particular anchor system and the life of an anchor will depend primarily on the load range for a particular limiting deflection. Secondly, alternating loads cause much more severe loading conditions and the life of an anchor is markedly reduced. /TRRL/

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  • Corporate Authors:

    Foundation Publications Limited

    7 Ongar Road
    Brentwood CM15 9AU, Essex,   England 
  • Authors:
    • HANNA, T H
    • Sivapalan, E
    • Senturk, A
  • Publication Date: 1978-4

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 28
  • Serial:
    • GROUND ENGINEERING
    • Volume: 11
    • Issue Number: 3
    • Publisher: EMAP CONSTRUCT LIMITED
    • ISSN: 0017-4653

Subject/Index Terms

Filing Info

  • Accession Number: 00183411
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Dec 29 1978 12:00AM