Access to London's Heathrow airport will be improved by a new extension of the Underground railway. Natural-rubber bearing pads will ensure that houses near the new line are not disturbed by traffic vibration. The extension, 3.5 mi (5.6 km) long, will be in a tunnel constructed by the cut and cover technique. A novel feature of the line is that in the residential area of Hounslow the track is not laid directly on the floor of the tunnel. Instead it is contained in reinforced concrete troughs, each 7m (22 ft) long and weighing about 20 tons. After the concrete has set the precast units are lowered into place with specially designed handling equipment. The separate troughs are then joined with in situ concrete to form two continuous parallel decks. It is here that the natural rubber bearings become involved. They fulfil a dual role. They function as transverse strip bearings. Each trough is symmetrically supported by two rows, 18 ft (5.4 m) apart, of five bearings. These take care of the vertical load. In addition, bearings will be inserted between each trough and the tunnel wall, and between the two troughs; here they function as supporting side bearings.

  • Corporate Authors:

    Trade and Technical Press, Limited

    Crown House
    Morden, Surrey SM4 5EW,   England 
  • Authors:
    • Rose, I G
  • Publication Date: 1974-3

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00057436
  • Record Type: Publication
  • Source Agency: Engineering Index
  • Files: TRIS
  • Created Date: Nov 12 1981 12:00AM