KILGETTY BYPASS: PROBLEMS RELATED TO THRUST FAULTING

The 6.3 km A477 Kilgetty bypass through undulating coastal topography across coal measures and millstone grit series strata required 2.6 km of cuttings, up to 32 m deep. The cut face design involved 1:2 batters in superficial material, 1:1 through weathered rock and 2:1 below a berm. The southern cutting, in a zone known to geologists as the variscan front, exposed clay gouge-filled thrust faults dipping into the cut, which caused localised small-scale instabilities in the 1:1 batter. Re-appraisal of the geological structure in the light of the new thrust fault model led to a re-design of the western cut batter. Although additional land take was necessary, the extra excavation was less than 20 000 cubic meter. For the covering abstract of the symposium see IRRD 286603. (Author/TRRL)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/0727702432
• Supplemental Notes:
  • From Proceedings of the Symposium on Failures in Earthworks, organized by the Institution of Civil Engineers, held in London, March 6-7, 1985.
• Corporate Authors:

  Thomas Telford Limited

  London,   United Kingdom 
• Authors:
  • Fletcher, A D
  • HAWKINS, A B
  • Jones, E H
• Conference:
  • From Proceedings of the Symposium on Failures in Earthworks, organized by the Institution of Civil Engineers, held in London, March 6-7, 1985.
• Publication Date: 1985

Media Info

• Features: Figures; Photos; References;
• Pagination: p. 315-327

Subject/Index Terms

• TRT Terms: Bypasses; Clay; Coasts; Failure; Faulting; Geology; Road construction; Slope stability; Thrust; Weathered rock
• Old TRIS Terms: Coal measures; Geology (Soils); Millstone
• ITRD Terms: 3420: Anchorage; 2709: Bypass (loop road); 8525: Conference; 2812: Cutting (earthworks); 9011: Design (overall design); 5520: Failure; 4068: Fault (geomorphol); 4053: Geology; 4029: Landslide; 3665: Road construction; 4154: Rock; 5783: Slope stability; 8119: United Kingdom; 5281: Weathering
• Subject Areas: Geotechnology; Highways;

Filing Info

• Accession Number: 00465016
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• ISBN: 0 7277 0243 2
• Files: ITRD, TRIS
• Created Date: Jan 31 1988 12:00AM