THE ORIGIN AND TREATMENT OF LONGITUDINAL CRACKS IN MASONRY ARCHES

This paper describes the movements and strains which occur in masonry arches, and considers how those strains lead to longitudinal cracks. The author doubts whether edge cracks are caused by outward movement of spandrel walls, and offers an alternative explanation which is more consistent with observations of midline cracks on railway bridges. Observations show that a crack propagates outwards from the centre of a span. This suggests that cracks can be produced only by relative movement of the arch barrel under the spandrel and fill. Once this relative movement has begun and caused a crack, any attempt to refasten it is more likely to do harm than good, especially when the bridge has demonstrably been performing adequately with the crack. If ties are required, they should be installed through the fill, not the barrel. The end of the paper considers some implications for assessment and repair of masonry arch bridges. In road bridges, cracks occur against the spandrel walls, not at midwidth. Thus any midwidth crack indicates some other form of behaviour, and must be investigated carefully. In railway bridges, the cracks are likely to extend further than in road bridges, and there are also centreline cracks. However, in many other respects, the behaviour of railway and road masonry arch bridges is similar.

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  • Corporate Authors:

    Institution of Structural Engineers

    11 Upper Belgrave Street
    London,   United Kingdom  SW1X 8BH
  • Authors:
    • HARVEY, W J
  • Publication Date: 1995-12-5

Language

  • English

Media Info

  • Features: References;
  • Pagination: p. 411-2
  • Serial:
    • Structural Engineer
    • Volume: 73
    • Issue Number: 23/24
    • Publisher: Institution of Structural Engineers
    • ISSN: 1466-5123

Subject/Index Terms

Filing Info

  • Accession Number: 00720806
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD
  • Created Date: May 24 1996 12:00AM