Earthworks for the Great Yarmouth Bypass are being built on a 20 M deep waterlogged bog using a combination of vertical wick drains, a fabric enclosed granular mattress and a continuously reinforced concrete road base. A polystyrene embankment is to be built in one place; 100 mm thick blocks about 2 M by 1 M will be laid in bond and sealed in a polythene sheet to protect them from petrol spillage. The top is covered by 1.7 M of sand and the sides will be protected by at least 600 mm of earth. On the main embankment, 17 M long vertical wick drains provide drainage upwards into a mattress of geogrid enclosed granular material which carries groundwater to side ditches. The 500 mm thick netlon mesh mattress restrains longitudinal and lateral spreading as the embankment settles. Edges of the mattress are shaped to form an anchor and the top and bottom sheets are stitched together to form continuous structural members. An extra layer of geogrid is laid on the higher embankments, more than 200 piezometers are linked to automatic readers to monitor pore pressures. Data are analysed by a pet computer using sarcmp stability analysis program. (TRRL)

Media Info

  • Features: Figures; Photos;
  • Pagination: p. 18-19
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00389485
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: Oct 30 1984 12:00AM