A preliminary assessment of the results obtained from a comprehensive field instrumentation and monitoring scheme of a deep basement in London clay, initiated in 1981 and expected to continue until at least 1987 and probably beyond, is presented. The aspect of particular interest is the performance of the 18 m deep perimeter diaphragm wall and the associated temporary works during construction of the basement. Details of the recorded wall movements, strut forces and strains developed within the wall are given together with observations of water pressures in the ground behind the wall. In addition the results of line and level surveys of the wall and the surrounding area are presented. Soils information extracted from the original site investigation report, together with results obtained from samples and in situ tests conducted during the installation of a deep borehole extensometer, are given. A comparison is made with the original design predictions of wall and ground movements, bending moments and strut loads. Tentative conclusions are drawn which suggest that the forces developed within the struts are within the design values; similarly strains in the wall derived from the design bending moments have not been exceeded. The dependence of the wall deformations on the speed and sequence of excavation is illustrated. The measurements to date suggest that the zone of influence with respect to movements of the surrounding ground is confined to the immediate vicinity of the excavation. (TRRL)

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 563-579
  • Serial:
    • Volume: 34
    • Issue Number: 4
    • Publisher: Thomas Telford Limited
    • ISSN: 0016-8505

Subject/Index Terms

Filing Info

  • Accession Number: 00395069
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: Aug 31 1985 12:00AM