Variations of stiffness and compaction state by the degree of compaction

The elastic shear modulus, G0, the resilient modulus Mr and other strength/stiffness indexes, therefore the stress-strain properties, of compacted soil relevant to the design of road soil structures are controlled by not only dry density, ρd (or the degree of compaction, Dc=ρd/”maximum dry density, (ρd)max”) and soil type, but also the degree of saturation, Sr, at the end of compaction. These properties during service are controlled also by Sr during service. Therefore, the compacted state in terms of ρd and water content, w (or Dc and Sr) cannot be identified only from G0 or another strength/stiffness index, but the value of Sr is also necessary. On the other hand, the optimum degree of saturation, (Sr)opt, defined as Sr when ( ρd)max is obtained for given compaction energy level, CEL, and soil type; the unified compaction curve in terms of ρd/(ρd)max vs. Sr - (Sr)opt relation; and the compaction coefficient, C, expressing the effects of CEL on (ρd)max, are rather insensitive to variations of soil type and CEL. So they can be assumed to be constant in a given earth project in which inevitable variations of soil type and CEL are limited by their control. Soil compaction control based on G0 or another strength/stiffness index together with Sr is proposed. A method to estimate the stress-strain properties of compacted soil from the values of G0 or another strength/stiffness index together with “Sr - (Sr)opt” is also proposed. These methods are not affected by limited variations of soil type and CEL.

  • Supplemental Notes:
    • This paper was sponsored by TRB committee AFP30 Standing Committee on Soil and Rock Properties.
  • Corporate Authors:

    Transportation Research Board

    ,    
  • Authors:
    • Tatsuoka, Fumio
    • Correia, António Gomes
  • Conference:
  • Date: 2019

Language

  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References;
  • Pagination: 14p

Subject/Index Terms

Filing Info

  • Accession Number: 01698217
  • Record Type: Publication
  • Report/Paper Numbers: 19-00632
  • Files: TRIS, TRB, ATRI
  • Created Date: Dec 7 2018 9:49AM