SEISMIC-REFRACTION ANALYSIS FOR LAYERED SOIL AND ROCK FORMATIONS CONTAINING BOULDERS, CAVITIES, AND BEDDED IRREGULARITIES

SIGNIFICANT RESULTS OF INTEREST TO ENGINEERS AND GEOLOGISTS INVOLVED IN VARIOUS PHASES OF HIGHWAY CONSTRUCTION MAY BE SUMMARIZED AS FOLLOWS: (1) THROUGH THE USE OF SEISMOGRAM DATA OBTAINED FROM REVERSED- PROFILE REFRACTION SURVEYS, THE EXISTENCE OF A CROSS- BEDDED LAYER IN A SEQUENCY OF LAYERED MEDIA CAN BE DEFINED, AND THE APEX OF THE CROSS-BEDDED LAYER CAN BE LOCATED WITH RESPECT TO THE SHOT POINTS. BY UTILIZING SEISMOGRAM DATA OBTAINED FROM PARALLEL AND PERPENDICULAR REVERSED-PROFILE REFRACTION SURVEYS, A SEQUENCE OF LAYERED FORMATIONS, INCLUDING THE PRESENCE OF A LAYERED FORMATIONS, INCLUDING THE PRESENCE OF A CROSS-BEDDED LAYER, CAN BE DETERMINED IN A THREE- DIMENSIONAL SENSE. THE COMPUTER PROGRAM REFRAC3 HAS BEEN DEVELOPED TO INTERPRET REFRACTION DATA FROM THE VIEW POINTS OF THE THICKNESSES AND DIPS OF A SEQUENCE OF ROCK AND SOIL FORMATIONS, THE EXISTENCE AND APEX LOCATION OF A CROSS-BEDDED LAYER, THE PROBABLE MATERIAL COMPOSITION AND ESTIMATED RELATIVE RIPPABILITY OF EACH LAYER, AND TO PROVIDE GRAPHICAL PLOTS OF THE TRAVEL-TIME CURVES AND SUBSURFACE CROSS SECTION. (2) THE LOCATION OF CAVITIES AND BOULDERS WITHIN A LAYER, OR AT AN INTERFACE BETWEEN TWO LAYERS, BY SEISMIC REFRACTION IS RELATIVELY MORE DIFFICULLT THAN DETERMINING CROSS-BEDDED LAYERS, AND REQUIRES A MORE DETAILED SURVEY CONFIGURATION WITH THE POSSIBLE COMPLEMENTARY USE OF SEISMIC REFRACTION. (3) THROUGH THE COMPLEMENTARY USE OF SEISMIC REFRACTION AND REFLECTION, THE THICKNESS OF A SINGLE, HORIZONTAL ANISTROPIC LAYER OVERLYING EITHER AN ISOTROPIC OR ANISOTROPIC LAYER CAN BE DETERMINED. THE DETERMINATION OF THE THICKNESSES AND DIPS OF A SEQUENCE OF ANISOTROPIC LAYERS APPEARS TO BE RELATIVELY DIFFICULT, AND PROBABLY REQUIRES SEVERAL INDEPENDENT REFLECTION AND REFRACTION SURVEYS. (4) THE RELATIVE RIPPABILITY OF A SOIL OR ROCK FORMATION DEPENDS ON THE PARTICULAR RIPPER-TRACKER COMBINATION, AND CAN BE RELATED TO SEISMIC WAVE VELOCITY. /AUTHOR/

  • Corporate Authors:

    South Dakota School of Mines and Technology, Rapid City

    501 East St Joseph Street
    Rapid City, SD  USA  57701

    South Dakota Department of Transportation

    700 East Broadway Avenue
    Pierre, SD  USA  57501

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  USA  20590
  • Authors:
    • Gnirk, P F
    • Fossum, A F
    • Svalstad, D K
  • Publication Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 00228671
  • Record Type: Publication
  • Source Agency: Federal Highway Administration
  • Report/Paper Numbers: 611 (69)
  • Files: TRIS, USDOT, STATEDOT
  • Created Date: Aug 8 1971 12:00AM