This article describes the processes and problems involved in the construction of two sets of diaphragm walls (one more than 30m deep and within 2m of the shop fronts on either side of Glasgow's busiest shopping street) and the other more than 24m deep from within an existing tunnel with only 4.5m of headroom for the purpose of widening a subway tunnel to make room for an underground station with an island platform. The need for minimal disruption to normal activity along a major shopping area, as well as the maintence of emergency access for fire-fighting and the like, and the limited space affected both design and construction procedures. The diaphragm walling was carefully programmed so as to permit as early a start on the actual construction of the station at the east end of the station area while the diaphragm walling continued to proceed westward (eg., because movement of construction equipment to and from the sites was limited to the evening hours, equipment needs had to be taken into account several shifts in advance so as to prevent delays caused by the lack of a vital piece of equipment). The outer disphragm walls were formed in panels 3-4.1m long which were installed after excavation through sand, clay with silt and gravel linses overlying a dolerite bedrock and which extended vertically from street level down 23-30m to up to 300 mm into the rock. Bentonite slurry was provided to each panel site via a pipeline linked to a mixing and storage area away from the street. Exacavation on the narrow street was accomplined by a unit suspended from twin cables and mounted on a crane. Special excavators, had to be used also when the inner diaphragm walls were construced from within the old tunnel prior to its domolition because of the low head room. (4.5m). Headroom also restricted the length of panel reinenforcement cages that could be handled. Sections were installed in 3.5m lengths using a small crane and lowered into the trenches, subsequent elements being spliced on by mean of bulldog clamps to give the requried final deth. Concrete was either brought in by trucks from Central Station 0.8 km away or, when space was limited, pumped from the surface.

  • Availability:
  • Corporate Authors:

    Foundation Publications Limited

    7 Ongar Road
    Brentwood CM15 9AU, Essex,   England 
  • Publication Date: 1978-7

Media Info

  • Features: Figures; Photos;
  • Pagination: p. 19-24
  • Serial:
    • Volume: 11
    • Issue Number: 5
    • ISSN: 0017-4653

Subject/Index Terms

Filing Info

  • Accession Number: 00184595
  • Record Type: Publication
  • Source Agency: Ground Engineering
  • Files: TRIS
  • Created Date: Feb 3 1981 12:00AM