A NEW APPROACH TO THE CLASSIFICATION OF QUICK CLAYS

Highly sensitive clays with S greater than 50, according to common definitions called quick clays, show very different behaviour when influenced by vibration, shocks and other external forces. In extreme cases quick clay samples are impossible to handle and are liquefied when subjected to only small deformations. In other cases a large amount of working is needed to break down the quick clay structure. This means that quick clays can be broken down more or less rapidly. The first type of clay has therefore in this report been called "rapid quick clay" and the other "slow quick clay". In order to obtain a measure of the rapidity and prepare a rough classification of the quick clays a testing procedure, based on Casagrande's liquid limit device, was tried and a rough classification scale formed. The scale ranges from a rapidity number of 1 for the most stable clay to a rapidity number of 10 for the most fragile. When comparing the rapidity scale with old descriptions of quick clays, it is found that quick clay in its original sense corresponds to a rapidity number of at least 8. Tentatively, a new definition of quick clay is proposed by the Author, viz, a clay with a sensitivity of at least 50 and with a rapidity number of at least 8. Field studies from three places in western Sweden indicate that highly sensitive clays throughout the whole scale range exist. The importance of highly rapid quick clays and the potential risks in connection with their existence in mechanically unstable slopes is touched upon.

• Corporate Authors:

  Swedish Geotechnical Institute

  Banergaten 16
  S-115-26 Stockholm,   Sweden 

  Swedish Geotechnical Institute

  Banergaten 16
  S-115-26 Stockholm,   Sweden 
• Authors:
  • Soderblom, R
• Publication Date: 1974

Media Info

• Features: Figures; References; Tables;
• Pagination: 17 p.
• Serial:
  • Swedish Geotechnical Inst Reprints & Prelim Repts
  • Issue Number: 55

Subject/Index Terms

• TRT Terms: Classification; Deformation; Liquid limits; Sensitive clays; Testing; Vibration
• Subject Areas: Geotechnology; Highways;

Filing Info

• Accession Number: 00082915
• Record Type: Publication
• Files: TRIS
• Created Date: Apr 8 1975 12:00AM