A35 SLIP STABILISATION

This article describes stabilisation works on the A35 road between Charmouth and Morcombelake in Dorset, England. This section of the A35 had to be closed to traffic during the latter part of 1995. It crosses relict landslip terrain, where it climbs the lower slopes of Stonebarrow Hill near Charmouth. Subsidence and cracking had occurred along 80m of the road at the beginning of 1994. Investigations conducted in February 1994 included: (1) the installation of inclinometers and piezometers in boreholes in the subsidence site; and (2) excavation of a trial trench up to 3.0m deep across one lane. The underlying ground is mostly clay, but also sand and silt. Temporary remedial measures were undertaken to allow the lane to be reopened. After prolonged heavy rain, further cracking/subsidence occurred in January 1995, distorting the carriageway sufficiently to require the lane's closure for three months. By then, the rate of movement had reduced significantly, enabling the whole road to be kept open during the summer holiday period. The zone of movement was confirmed to be within silty clay hill disturbed material, also containing gravels. A full 225,000 pound repair contract was specified and successfully completed during Autumn 1995. Monitoring instruments have as yet found no further ground movement on the road since then.

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  • Corporate Authors:

    INSTITUTION OF HIGHWAYS & TRANSPORTATION

    6 ENDSLEIGH STREET
    LONDON,   United Kingdom  WC1H 0DZ
  • Authors:
    • GREEN, RGV
    • HOLTOM, P H
  • Publication Date: 1996-4

Language

  • English

Media Info

  • Pagination: p. 15-7
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00725466
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD
  • Created Date: Sep 26 1996 12:00AM