The vibroflotation methods are described (which consist essentially of surface vibration or rolling) in which a metal tube is inserted into the ground which has within its lower end an electric motor driving an eccentric weight, by this means imparting vibrations into the ground as the tube was inserted to a required depth. Limitations encountered when dealing with sands of high silt or clay content are discussed. Treatment of the ground by the "stone column" process is described, as well as treatment by the Dynamic Consolidation process. The latter process (which is suitable for large areas where the ground is of non-cohesive granular materials, partially, saturated clay fills & older deposits of refuse and other debris) consists of tamping the area to be treated on a predetermined pattern with a weight of between 8-20 tonnes dropping in free fall from 8 to 20 meters. Ground conditions suitable for treatment are reviewed with particular reference to conhesionless soils. In cohesive soils, granular backfill is introduced around the vibroflot to form stone columns which are located directly beneath the foundations and generally extend down to firmer ground. Alternatively, in ground where the strength increases with depth, a depth of treatment based on conventional elastic theory is used. Comments are made on the way in which fill materials and older refuse tips respond to ground treatment. After treatment the ground is considered, for the purposes of foundation design, to act as a semi-elastic medium of relatively uniform properties. Observations are made regarding new roads and motorways which are required to cross areas of soft organic clays and peat deposits.

  • Supplemental Notes:
    • Presented at Seminar X (Road Design 1: General Topics) of the PTRC Summer Annual Meeting, Warwick University, England, 8-12 July 1974.
  • Corporate Authors:

    Planning and Transport Res and Computation Co Ltd

    167 Oxford Street
    London W1R 1AH,   England 
  • Authors:
    • THOMSON, G H
  • Publication Date: 1974-7

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Filing Info

  • Accession Number: 00096290
  • Record Type: Publication
  • Report/Paper Numbers: PTRC/P/108
  • Files: TRIS
  • Created Date: Sep 10 1975 12:00AM