The author briefly reports on the progress of the rock stabilizing contract on Bristol's portway section of the A4 trunk road tunning through the Avon Gorge. This road has been closed following the discovery of potentially dangerous portions of rock in the cliffs. It was decided to remove all of the approximately 2,500 tons of rock as opposed to using rock anchors. To regularize an otherwise difficult contract situation, the work has been divided into five sections, estimates having been submitted for maximum, minimum and mean quantities of rock ranging from 50 cubic metres to 8,000 cubic metres. The method being employed uses two sets of scaffolding erected either side of the promontory of a site 3M above the roadway. From this scaffolding drilling and the placement of rock anchors is carried out so that steel cables can be tensioned around the rock to aid stability and to limit the size of rock fragments which may break away. The drilling work has provided useful additional information. A blanket of gravel will protect the portway during the blasting operations. /TRRL/

  • Availability:
  • Corporate Authors:

    IPC Building and Contract Journals Limited

    32 Southwark Bridge Road
    London SE1 9EX,   England 
  • Authors:
    • Atkinson, I
  • Publication Date: 1975-7-10

Media Info

  • Features: Photos;
  • Pagination: p. 24
  • Serial:
    • Volume: 266
    • Issue Number: 5001
    • Publisher: Reed Business Information, Limited
    • ISSN: 0010-7859

Subject/Index Terms

Filing Info

  • Accession Number: 00127909
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Dec 29 1975 12:00AM