Details:

Creators:
Tran, Khiem T. ; Hiltunen, Dennis R. ; Sarno, Ariel I. ; Hudyma, Nick
Tran, Khiem T. ; Hiltunen, Dennis R. ; Sarno, Ariel I. ; Hudyma, Nick Less -
Corporate Creators:
University of Florida. Dept. of Civil and Coastal Engineering
Subject/TRT Terms:
[+]
Annealing Drilled Shafts Finite Difference Foundations Full Waveform Geophysical Prospecting Geotechnical Engineering Global Optimization Rock Mechanics Rocks Rock Sockets Seismic Waves Simulated Annealing Underground Structures
Resource Type:
Tech Report
Geographical Coverage:
Florida
Edition:
Final Report; May 2008-February 2011
Corporate Publisher:
Florida. Department of Transportation. Research Center
Abstract:
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.


Format:
PDF
Funding:
BDK-75-977-01
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:e26e57bdc6390e8aa87a65715569a3eef5f6d724714ab396876f686a3e3ff7ab
Download URL:
https://rosap.ntl.bts.gov/view/dot/18627/dot_18627_DS1.pdf
File Type:

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