OVERCONSOLIDATED GLACIAL TILLS IN EASTERN WISCONSIN

A geological and geotechnical analysis of overconsolidated till units in eastern Wisconsin forms the basis of this paper. The glacial stratigraphy and geotechnical properties (grain size, clay mineralogy, Atterberg limits, hydraulic conductivity, strength, and compressibility) of the till units are presented based on a large number of tests on samples from a wide geographical area. The clay tills exhibit varying degrees of overconsolidation depending on their vertical location, but there is no discernible difference between the overconsolidation ratio of different till units with the same effective overburden stress. The preconsolidation stresses are much lower than the total ice pressure, indicating limited drainage during ice loading, possibly because of permafrost conditions that prevailed during the deposition of these tills. The higher overconsolidation ratios and preponderance of jointing encountered in the upper 10 m of these tills could be attributed to groundwater lowering resulting from a drier climate that prevailed subsequent to their deposition. The theories of transport and deposition of glacial till are reviewed and interpreted for the tills of eastern Wisconsin.

Language

  • English

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 99-106
  • Monograph Title: Engineering properties and practice in overconsolidated clays
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00713481
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Nov 2 1995 12:00AM