ROAD ENGINEERING IN NZ SOFT ROCK MATERIALS. NEW ZEALAND ROADING SYMPOSIUM 1987. VOLUME 1

This paper presents an overview of New Zealand sedimentary soft rock (papa) research projects which have been supported by the Road Research Unit. Emphasis is given to those aspects which are considered to be of value to roading engineering, particularly in the design and construction of cut slopes and embankment fills. Observations on suitable construction practice for soft rocks are included. Geological features of soft rocks and their distribution are summarised and laboratory tests investigated to describe their engineering characteristics discussed. It is concluded that soft rocks generally exhibit properties associated with heavily over consolidated soils. Petrological aspects, particularly related to the microfabric of soft rocks, and their significance related to material behaviour are described. Observations of cut slope performance are presented both from general visual surveys and the detailed monitoring of cut slopes. Slabbing and fretting (slaking) are the two common slope failure modes in massive soft rocks when structural features are absent. Compacted fill embankments are discussed. Research findings indicate that without exception, sedimentary soft rock materials should be treated as soils and compacted as earth fills for reliable long term performance. Poor performance of embankments has usually been related to poor compaction and/or poor foundation conditions, particularly drainage. Recommendations related to the use and construction practices appropriate for soft rock materials are presented. For the covering abstract of the symposium see IRRD 810782. (Author/TRRL)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/0477071562
• Corporate Authors:

  National Roads Board, New Zealand

  P.O. Box 12-041
  Wellington,   New Zealand 
• Authors:
  • Jennings, D N
  • Olsen, A J
  • READ, S
  • Hupppert, F
  • Millar, P J
• Publication Date: 1987

Media Info

• Features: References;
• Pagination: p. 109-119
• Serial:
  • Publication of: UNITED NATIONS
  • Publisher: United Nations
  • ISSN: 0252-4392

Subject/Index Terms

• TRT Terms: Compaction; Conferences; Construction management; Drainage; Embankments; Failure; Geology; Geomorphology; Highway engineering; Performance; Petrography; Soft rock
• Geographic Terms: New Zealand
• ITRD Terms: 3686: Compaction; 5905: Compressibility; 8525: Conference; 3666: Construction method; 2812: Cutting (earthworks); 2937: Drainage; 5910: Durability; 2801: Embankment; 5520: Failure; 4053: Geology; 8079: New Zealand; 4060: Petrography; 4154: Rock; 4076: Structure (geomorphol)
• Subject Areas: Construction; Geotechnology; Highways; Hydraulics and Hydrology;

Filing Info

• Accession Number: 00476374
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• ISBN: 0-477-07156-2
• Files: ITRD, TRIS
• Created Date: Sep 30 1988 12:00AM