Welcome to ROSA P | Geophysical testing of rock and its relationships to physical properties - 18627 | US Transportation Collection >
Stacks Logo
Advanced Search
Select up to three search categories and corresponding keywords using the fields to the right. Refer to the Help section for more detailed instructions.
 
 
Help
Clear All Simple Search
Advanced Search
Geophysical testing of rock and its relationships to physical properties
  • Published Date:
    2011-02-01
  • Language:
    English
Filetype[PDF-6.27 MB]


This document cannot be previewed automatically as it exceeds 5 MB
Please click the thumbnail image to view the document.
Geophysical testing of rock and its relationships to physical properties
Details:
  • Resource Type:
  • Geographical Coverage:
  • OCLC Number:
    704283870
  • Edition:
    Final Report; May 2008-February 2011
  • NTL Classification:
    NTL-HIGHWAY/ROAD TRANSPORTATION-HIGHWAY/ROAD TRANSPORTATION ; NTL-HIGHWAY/ROAD TRANSPORTATION-Soils and Geology ;
  • Format:
  • Description:
    Testing techniques were designed to characterize spatial variability in geotechnical engineering physical parameters of

    rock formations. Standard methods using seismic waves, which are routinely used for shallow subsurface

    investigation, have limitations in characterizing challenging profiles at depth that include low-velocity layers and

    embedded cavities. This research focuses on overcoming these limitations by developing two new methods using both

    sensitive data and a global inversion scheme. The first method inverts combined surface and borehole travel times for

    a wave velocity profile. The technique is based on an extremely fast method to compute first-arrival times through the

    velocity models. The capability of this inversion technique is tested with both synthetic and real experimental data

    sets. The inversion results show that this technique successfully maps 2-D velocity profiles with high variation. The

    inverted wave velocities from real data appear to be consistent with cone penetration test (CPT), geotechnical borings,

    and standard penetration test (SPT) results. The second method inverts full waveforms for a wave velocity profile. The

    strength of this approach is the ability to generate all possible wave types and, thus, to simulate and accurately model

    complex seismic wave fields that are then compared with observed data to deduce complex subsurface properties. The

    capability of this inversion technique is also tested with both synthetic and real experimental data sets. The inversion

    results from synthetic data show the ability of detecting reverse models that are hardly detected by traditional inversion

    methods that use only the dispersion property of Rayleigh waves. The inversion results from the real data are generally

    consistent with crosshole, SPT N-value, and material log results. Employed for site characterization of deep foundation

    design, the techniques can provide credible information for material at the socket and partially detect anomalies near

    the socket. Lastly, based upon a laboratory testing program conducted on rock cores, it does appear that relationships

    between geophysical measurements and geotechnical engineering design parameters are credible, though significant

    scatter does exist in the data. It could be postulated that geophysical measurements should be capable of indentifying

    large zones of poor quality rock, and the results can provide characterization of spatial variability in geotechnical

    engineering physical parameters useful in the design of deep foundations.

  • Supporting Files:
    No Additional Files
No Related Documents.
You May Also Like:
Submit Feedback >