KRCEE

Project 8: Field Determination of S & P Wave Velocities for Ground Motion Model Input at the Paducah Gaseous Diffusion Plant, Paducah, Kentucky

PROJECT MANAGER

Steve Hampson, Assistant Director, Kentucky Research Consortium for Energy and Environment, University of Kentucky

PRINCIPAL INVESTIGATORS

Dr. Edward W. Woolery, Assistant Professor, Department of Geological Sciences
University of Kentucky

Dr. Zhenming Wang, Seismologist and Section Head (Geological Hazards)
Kentucky Geological Survey, University of Kentucky

BACKGROUND

Realistic determination of site response and modeling of earthquake induced ground motions at the Paducah Gaseous Diffusion Plant and vicinity cannot be accurately achieved without a reliable P- and S-wave velocity models developed at the network observation sites in the WKWMA. The objective of this investigation is to provide measured seismic P- and S-wave velocity models at each of the network expansion sites by combining data from in-situ seismic reflection/walkaway and seismic downhole surveys.

In addition to seismic wave velocity, other information such as the fundamental site period (i.e., natural frequency of soil overburden) and material damping to depth are needed for a complete and rigorous characterization of the site response. Assessing the damping ratio of the deeper sediments is important because the measured response of these materials will have a large impact on predicted ground motions. These characteristics will be gathered using the University of Kentucky's shear-wave vibroseis and removable surface and downhole geophones:

The vibroseis unit will also be used to evaluate the in situ damping properties of the site. By using steady state input, amplitudes will be identified at various depths and correlated to values of damping ratio. Separation of radiation damping from the measured value of damping will be necessary to evaluate accurately the material damping ratios over long distances.

The results of the field tests will be directly compared to any recorded earthquake motions to assess the extent of multi-dimensional site effects. This is particularly important in the vicinity of the PGDP, because it is situated near the northern boundary of the Mississippi embayment where 2- and 3-dimensional basin edge effects could be problematic and such tests have not been conducted and results input into site seismic models in order to accurately reflect site-specific PGDP ground motions.

Following assessment of field data the principal investigators and project team will write a summary report that will be submitted for professional journal publication. An independent technical review team, comprised of additional national and international experts, will be employed to peer review and finalize project results.

GOALS

To obtain site-specific S- and P-wave velocity field measurements at the PGDP.
To obtain field measurements of site specific soil damping properties at the PGDP.
To provide measured P- and S-wave velocity models at each of the PGDP seismic monitoring sites.
To provide accurate seismic models that reflect measured site specific S- and P-wave velocities and measured soil damping properties for the PGDP.

TIME FRAME

One Year

DELIVERABLES

Preliminary report and summary report summarizing the site specific P- and S-wave velocity models
Preliminary report and summary report summarizing the measured damping properties of PGDP soils.
Inclusion of site specific P- and S-wave velocity models and soil damping

TEAM MEMBERS

Dr. Edward W. Woolery, Assisstant Professor, Department of Geological Sciences

Dr. Zhenming Wang, Seismologist and Section Head (Geological Hazards), Kentucky Geological Survey

Steve Hampson, Assistant Director, Kentucky Research Consortium for Energy and Environment, University of Kentucky

REPORTS

Observed Seismicity in the Jackson Purchase Area of Western Kentucky

Seismic Hazard Assessment for Western Kentucky, Northeastern Kentucky and Southeastern Ohio

Seismic Velocity Measurements at Expanded Seismic Network Sites

KRCEE is a collaborative effort of Kentucky universities and is administered by the University of Kentucky.