The article describes the stabilization by dynamic consolidation of part of a disused colliery site on the firth of forth in Scotland. The compaction and strengthening of the free draining colliery shale was a preliminary to the construction of a pair of slipways to permit the launching of two North Sea oil rigs being built on the site. Because of the serious consequences of settlement under the huge loads involved, deep and dense compaction was required. The article describes how this was achieved by dynamic consolidation. A 14 tonne tamper, two metres square was dropped repeatedly by a 61rb crane from heights up to 25m. The modulus of deformation was increased from 15-45 mn/m2 to a minimum of 65mn/m2 by this technique, involving surface settlements of up to 2m. The compaction achieved was monitored using a pressure meter. This device, the article explains, is a type of composite load cell which allows 'down-the-hole' measurement of strength and compressibility. Water pressure is applied to a part of the cell and the deformation of the ground around it is sensed by another part. The pressure/volume change relationship thus obtained is used to give an indication of bearing capacity. The authors point out that although pore-pressure was not a problem at this site, by careful control of the energy input, dynamic consolidation can enhance the strength of wet cohesive soils. /TRRL/

  • Availability:
  • Corporate Authors:

    Foundation Publications Limited

    33 Short Croft
    Doddinghurst, Essex,   England 
  • Authors:
    • WEST, J M
    • Slocombe, B C
  • Publication Date: 1973-11

Media Info

  • Features: Figures; Photos; References;
  • Pagination: p. 52-54
  • Serial:
    • Volume: 6
    • Issue Number: 6
    • ISSN: 0017-4653

Subject/Index Terms

Filing Info

  • Accession Number: 00083193
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Jul 2 1975 12:00AM