GEOMORPHOLOGICAL OBSERVATIONS AS AIDS TO THE DESIGN OF COAST PROTECTION WORKS ON A PART OF THE DEE ESTUARY

A section of the southeast shore of the Dee Estuary is occupied by unstable cliffs formed of a complex succession of glacial deposits. Design of remedial works has necessitated an investigation of the nature and balance of geomorphological processes operating. Between 1973 and the present, a balance over a year has generally been achieved between failure of a clayey flow till in the upper cliff and erosion of the resulting colluvium from the toe. During exceptional storms, colluvium and in situ cohesive and non-cohesive materials are eroded, producing a rapid and larger-scale response at the crown of the slope. During winter, high pore water pressures are generated in perched water tables within the succession. Recent stabilization works at the toe in one downstream section appear to have caused severe toe erosion and slope instability over a distance of approximately 73 M of cliff line immediately upstream of the works. Geomorphological studies have also indicated appropriate angles for naturally stable slopes within this mixed succession. Grading or backfilling of the toe to achieve these specified slope angles, and toe protection with or without drainage, have been undertaken or are planned. This paper was presented at the Annual Regional Meeting of the Engineering Group of the Geological Society held at Birmingham University on 13-17 September 1982. (TRRL)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/04812085
• Corporate Authors:

  GEOLOGICAL SOCIETY

  BURLINGTON HOUSE, PICCADILLY
  LONDON,   United Kingdom  W1V 0JU
• Authors:
  • Pitts, J
• Publication Date: 1983

Media Info

• Features: Figures; Photos; References; Tables;
• Pagination: p. 291-300
• Serial:
  • QUARTERLY JOURNAL OF ENGINEERING GEOLOGY
  • Volume: 16
  • Issue Number: 4
  • Publisher: GEOLOGICAL SOCIETY
  • ISSN: 0481-2085

Subject/Index Terms

• TRT Terms: Backfilling; Clay; Colluvium; Conferences; Drainage; Erosion; Geomorphology; Glacial soils; Grading (Earthwork); Landslides; Pore water pressures; Prevention; Sand; Seas; Slope stability; Till; Toes; Water table
• Uncontrolled Terms: Grading
• Geographic Terms: United Kingdom
• ITRD Terms: 4198: Boulder clay; 4177: Clay; 8525: Conference; 5275: Erosion; 4055: Geomorphology; 4011: Glacial; 4029: Landslide; 9149: Prevention; 4105: Sand; 4368: Sea; 5783: Slope stability; 8119: United Kingdom
• Subject Areas: Geotechnology; Highways; Hydraulics and Hydrology; Security and Emergencies; I51: Earthworks and Soil Drainage;

Filing Info

• Accession Number: 00382474
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD, TRIS
• Created Date: Apr 30 1984 12:00AM