Sinkhole 3D-Imaging Workshop
University of Texas researchers welcome collaborators, offer travel support
Published on September 29, 2017
Photo: Oregon Department of Transportation
Researchers from the University of Texas at Austin are conducting a workshop on nonintrusive sinkhole 3D-imaging in Gainesville, Florida. The workshop will be held from 1 pm on Thursday, 26 October to 12 pm Friday, 27, October 2017.
The workshop will include presentations on the NHERI at Texas equipment and non-intrusive sinkhole imaging techniques, followed by a field demonstration of a proof-of-concept 3D imaging study at a Karstic Limestone Geophysical Ground Proving (KLGGP) site in Alachua County, Florida.
During the demonstration, NHERI@UTexas equipment will be used to collect a dataset of 3-dimensional waveforms that can be processed for 3D sinkhole imaging purposes via full-waveform inversion. Travel support is available for a number of participants. Preference will be given to those interested in submitting proposals to the Engineering for Natural Hazards (ENH) program of NSF.
Knowledge of the low-velocity anomalies (sinkholes) is crucial for the design and the safety of existing structures, since the anomalies can cause structural damage or collapse. Sinkhole and anomaly detection at a site usually begins with a non-destructive testing (NDT) assessment study, as NDT data can provide general subsurface conditions over a large volume of materials. The KLGGP site currently contains a number of survey lines and five PVC-cased boreholes extending to approximately 15 m. The site is unique because the northern portion of the retention pond commonly experiences sinkhole activity, whereas the southern portion rarely experiences sinkhole activity. The KLGGP site is located outside of Newberry, Florida on State Road 26 in Alachua County. The site is approximately 29 km from Gainesville, and approximately 150 km from Jacksonville. The northern portion of the site has been susceptible to sinkhole formation and a number of large sinkholes have formed and been repaired. However, the southern portion has been relatively free of sinkholes and is an ideal location for characterizing karst limestone sites.
The NHERI@UTexas workshop on nonintrusive, 3D-imaging of sinkholes will highlight a potential use of NHERI@UTexas equipment for true 3D non-intrusive imaging of geotechnical systems using full waveform inversion. Specifically, during the workshop, we will use the urban, mobile, hydraulic shaker named Thumper to generate dynamic vertical and horizontal loadings at the ground surface. The waveforms recorded from this testing will be provided to all workshop participants and other interested researchers to use in full waveform inversion studies to develop 3D models of potential sinkholes and underlying soil/rock deposits.
Those with ideas about small, proof-of-concept tests that could piggyback on the sinkhole imaging workshop in order to generate preliminary proposal data are encouraged to contact us in advance of the workshop.
Please contact Farnyuh Menq (fymenq@utexas.edu), NHERI@UTexas Site Operations Manager, with any questions regarding the workshop, piggyback proof-of-concept tests, or the equipment facility.