USING GEOLOGIC MAPS AND SEISMIC REFRACTION IN PAVEMENT-DEFLECTION ANALYSIS

The researchers examined the relationship between three data types - geologic maps, pavement deflection, and seismic refraction data - from diverse geologic settings to determine whether geologic maps and seismic data might be used to interpret deflections and assess pavement condition. Deflections measured with the Falling-Weight Deflectometer (FWD) are correlated to bedrock type as depicted on geologic maps, particularly at distant sensors. Comparisons of FWD data with mapped geologic units along six roadway segments revealed differences in FWD response that are likely to be related to differences in either bedrock type or depth. From FWD data alone, it is difficult to determine whether the relationship between rock type and deflections is caused by differences in bedrock type or depth. To resolve this ambiguity, the researchers employed the FWD and a soil-probe hammer as impulsive sources for seismic-refraction experiments at three test sites. The refraction experiments suggest that combined FWD-refraction systems could be used on pavement to aid deflection analysis by estimating bedrock depth and assist in rock-type identification by measuring compressional velocities for bedrock and overburden. The success of the refraction experiments led to the design and construction of a refraction system optimized for on-pavement use.

Language

  • English

Media Info

  • Features: Appendices; Figures; Photos; References; Tables;
  • Pagination: 128 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00793238
  • Record Type: Publication
  • Report/Paper Numbers: TX-00/2990-S,, Report No. 2990-S,, Project Summary Report
  • Contract Numbers: 7-2990
  • Files: NTL, TRIS, ATRI, STATEDOT
  • Created Date: May 18 2000 12:00AM