SHALLOW REFRACTION SURVEYS ON A LOW-VOLUME ROAD FOR DETERMINING P-WAVE VELOCITY OF SEASONAL THAWING SOILS

Determination of soil strength during spring thaw is essential to developing mechanistically determined seasonal load restrictions. The work reported uses shallow refraction techniques to determine P-wave velocities of the road subgrade at weekly intervals. From this information, the variation of P-wave properties with time is developed. From the relationship between P-wave velocity and time, it is shown that P-wave velocity starts at relatively high values before thaw commences, decreases to a minimum, and then increases. The minimum P-wave velocity occurs at about 3 weeks after the maximum degree-days for the freezing season. Results from the P-wave tests are shown to be comparable to results obtained using a Clegg impact test. However, the minimum Clegg value occurs at an earlier date than the minimum P-wave velocity. Overall, results indicate that shallow refraction surveys can be used to develop a curve of P-wave velocity versus time. This relationship, in turn, can be related to a soil strength value that would be usable in a mechanistic pavement design method.

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 232-236
  • Monograph Title: Fifth International Conference on Low-Volume Roads May 19-23 1991, Raleigh, North Carolina, USA; volumes 1 and 2
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00611805
  • Record Type: Publication
  • ISBN: 030905715
  • Files: TRIS, TRB
  • Created Date: Aug 31 1991 12:00AM