PILED RAFTS FOR SECTION OF NORTH WALES A55 EXPRESSWAY WORKS

An intensive programme of work has been started to improve access into North Wales, involving the construction of a road along a route said to present more topographical problems than any other compatible route in the UK. The article gives an outline of the three separate stages of construction with details of the work currently being undertaken in the section through Colwyn Bay over a valley of soft alluvial silts of low bearing capacity subjected to flooding. Mebra wick drains have been installed over an area of the next contract to provide information for its design. For reasons of assured reliability related to the time factor, it was decided to use piled rafts for the new railway alignment and to provide a solid foundation for the PFA road embankment beyond. Shell piling has been adopted using 3 ft long precast elements. A reinforcement cage is inserted inside the 12 inch internal diameter shell before filling with concrete to form the core. The piles are generally at 2 M centres along the two lengths, one of 735 M and the other of 1715 M. The unreinforced tops of the piles are trimmed mechanically before the rolled concrete rafts are constructed over them. (TRRL)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00174653
• Corporate Authors:

  Foundation Publications Limited

  7 Ongar Road
  Brentwood CM15 9AU, Essex,   England 
• Publication Date: 1984-1

Media Info

• Features: Photos;
• Pagination: p. 23-26
• Serial:
  • GROUND ENGINEERING
  • Volume: 17
  • Issue Number: 1
  • Publisher: EMAP CONSTRUCT LIMITED
  • ISSN: 0017-4653

Subject/Index Terms

• TRT Terms: Alluvium; Bearing capacity; Concrete structures; Drainage; Floods; Foundations; Loads; Mat foundations; Pipe; Precast concrete; Road construction; Sheet metal; Silts; Support piles; Wick drains
• Geographic Terms: United Kingdom
• Old TRIS Terms: Pile shell; Raft
• ITRD Terms: 3085: Bearing capacity; 2937: Drainage; 2569: Flooding; 3377: Foundation; 5567: Load; 3399: Pile; 3361: Pipe; 4792: Precast concrete; 3665: Road construction; 3397: Shallow foundation; 4149: Silt; 8119: United Kingdom
• Subject Areas: Construction; Highways; Hydraulics and Hydrology; I52: Construction of Pavements and Surfacings;

Filing Info

• Accession Number: 00389521
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD, TRIS
• Created Date: Oct 30 1984 12:00AM