Details are given of the concrete and steel structure gallery built to protect the A4 Hotwells Road that flanks the Avon Gorge near Bristol. The gallery, 90 M long, is to be laid to a 265 M radius on plan; it has an in-situ reinforced concrete abutment on the cliff side of the road. This will have counterforts to the cliff face at 7 M centres, each of which will house a vertical array of rock anchors. In situ concrete columns opposite the counterforts will form a colonnade on the other side of the road. Minimum 6.1 M headroom will be afforded by a system of simply-supported longitudinal 900 mm deep steel plate girders supporting similar transverse plate girders at 1.2 M centres. The transverse beams will act compositely with a waterproofed 300 mm thick concrete deck. Crushed limestone aggregate, covering the roof deck to an average depth of 2 M, will serve both to absorb the impact from falling rock and to marry the structure into the surrounding rock scree. The structure has been designed assuming an annual probability of a 9.5 M3 rock mass impact and a once-in-50-years impact from a 1.5 M3 rock mass. For the 0.5 M3 rock size design stresses are within elastic limits. For the larger impact condition, plastic deformation with deflection limited to 3 times the elastic deformation was adopted. The roof is in sections that can be replaced when damaged. (TRRL)

  • Availability:
  • Corporate Authors:

    IPC Building and Contract Journals Limited

    Surrey House, 1 Throwley Way
    Sutton, Surrey SM1 4QQ,   England 
  • Authors:
    • Atkinson, I
  • Publication Date: 1979-10-11

Media Info

  • Features: Figures; Photos;
  • Pagination: p. 38-39
  • Serial:
    • Volume: 291
    • Issue Number: 5223
    • Publisher: Reed Business Information, Limited
    • ISSN: 0010-7859

Subject/Index Terms

Filing Info

  • Accession Number: 00309035
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: Jun 26 1980 12:00AM