Effects of the Degree of Saturation of the Stiffness and Dry Density Relation of Compacted Soil

One of the fastest and most efficient methods to evaluate the compacted state in a given earthwork project is the one based on the elastic shear modulus, G0, or the resilient modulus, Mr. A stiffness index, called Compaction Control Value, CCV, obtained from the response accerelation of a vibratory compaction roller is widely used. Full-scale compaction tests were performed on a silty sand to evaluate the relationship CCV and the dry density, ρd. Similarly as CBR and G0 or other strength/stiffness indexes, for a given soil type, CCV is controlled by not only ρd but also the degree of saturation, Sr, at the end of compaction. For a constant value of ρd, CCV increases with a decrease in Sr, in particular largely when Sr becomes smaller than the optimum degree of saturation, (Sr)opt (i.e., Sr when the maximum dry density, (d)max, is obtained for a given set of soil type and compaction energy level, CEL). An empirical equation was derived in which CCV is expressed by a function of ρd and Sr not including CEL as a variable. This fact implies that it is not possible to evaluate the compacted state only from CCV (as in the case with CBR and G0), but the Sr value should also be evaluated. By evaluating the water content during a given process of compaction, the the compacted state in terms of ρd and Sr can be evaluated in real time from the continuous measurement of CCV.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AFP60 Standing Committee on Engineering Behavior of Unsaturated Geomaterials.
• Corporate Authors:

  Transportation Research Board

  ,    
• Authors:
  • Nagai, Hiroyuki
  • Nishio, Tatsufumi
  • Sandambata, Isamu
  • Makabe, Jun
  • Kogusuri, Haruna
  • Tatsuoka, Fumio
  • Kikuchi, Yoshiaki
  • Hyodo, Taichi
• Conference:
  • Transportation Research Board 98th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2019-1-13 to 2019-1-17
• Date: 2019

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: 9p

Subject/Index Terms

• TRT Terms: Compacted soils; Dry density; Modulus of resilience; Moisture content; Saturated soils; Soil compaction; Stiffness
• Subject Areas: Geotechnology; Highways; Pavements;

Filing Info

• Accession Number: 01697721
• Record Type: Publication
• Report/Paper Numbers: 19-01899
• Files: TRIS, TRB, ATRI
• Created Date: Mar 1 2019 3:51PM