Contact

Bret M. Webb, Ph.D., P.E., D.CE
Professor
University of South Alabama
150 Jaguar Drive, SH3142
Mobile, AL 36688 USA
Phone: (251) 460-6174
Fax: (251) 461-1400
Email: bwebb@southalabama.edu

Research Positions

None available at this time

Current Research Assistants

SE Students
Garland Pennison

 

MSCE Students
Patrick Hautau
Marshall Hayden
Kate Haynes
Justin Lowlavar
Vijaya Satya Lohitha Mukkamala
Jackie Wittmann

 

Undergraduate Students
Derek Kelly
Rh'Monte Wilson

Former Students

MSCE Students
Bryan Groza (2016)
Kari Servold (2015)
Chris Marr (2013)
Richard Allen (2013)
Miyuki Matthews (2012)

 

Post Docs
Jon Risinger
Jungwoo Lee

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I would like to welcome Dr. Jon D. Risinger to the University of South Alabama. Dr. Risinger has accepted a position as a postdoctoral research assistant in the Department of Civil Engineering at USA. Dr. Risinger received a BS in Biological and Agricultural Engineering from the Louisiana State University, an MSCE in Water Resources from Cal State Fresno, and a PhD in Biological/Biosystems Engineering and Coastal Science from the Louisiana State University. Dr. Risinger’s expertise and current areas of practice and research are in biologically dominated breakwater reefs and so-called non rock alternatives for shore protection. While at USA, Dr. Risinger will be performing research on biologically dominated breakwater reefs in the USA Wave Basin facility. Please visit Dr. Risinger’s {LinkedIn} page for more information.

 

 

 

The Nature Conservancy (TNC) is funding Dr. Webb to study Mobile Bay’s wave characteristics to facilitate preparation, planning, site selection, and design of their coastal projects in Alabama. Products of the study will include high-resolution estimates of seasonal and probabilistic wave characteristics along Alabama’s coastline; and tools for evaluating the performance of wave attenuating structures during storm events. The expected outcomes of the study include improved site selection, appropriate project design based on wave climate, and the ability to quantify wave height reduction as a function of the local wave climate, project design, and storm-induced water levels.

A number of CE graduate students and faculty are presenting their research at the annual USA Spring Research Forum the week of March 26 – 30, 2012. Research posters are displayed in the lower and upper lobby of the Mitchell College of Business (MCOB). A formal research symposium will be held on Friday, 3/30. The CE posters are on the lower lobby level on boards 17 – 20. Students are encouraged to view the posters to gain an appreciation for the research that USA students, both undergraduate and graduate, and faculty are performing. Some reduced-scale versions of the posters can be found below the corresponding citations that follow. Please contact me if you’d like more information about these or other projects.

 

  • Allen, R.J., B.M. Webb 2012. Wave Attenuation Devices: a Comprehensive Evaluation of Wave Transmission through Physical Modeling. University of South Alabama Spring Research Forum, Poster 20. March 26 – 30, 2012. Mobile, AL.

 

  • Marr, C.D., B.M. Webb 2012. Spatial Variability of Residence Time in Mobile Bay, Alabama. University of South Alabama Spring Research Forum, Poster 19. March 26 – 30, 2012. Mobile, AL.

 

  • Miyuki, M.T., B.M. Webb 2012. Characterizing Wave-Induced Scour Processes in a Transition Zone: a Continuum Model for Equilibrium Scour Depth at Cylindrical Piles. University of South Alabama Spring Research Forum, Poster 18. March 26 – 30, 2012. Mobile, AL.

 

  • Webb, B.M., S.H. Russ, D.B. Martin. 2012. Development of an Enhanced Ocean Drifter. University of South Alabama Spring Research Forum, Poster 17. March 26 – 30, 2012. Mobile, AL.

 

Two papers were recently accepted for presentation and publication at the 2011 ASCE COPRI Conference on Coastal Engineering Practice.  One of the papers presents a critical analysis of strategies and efforts applied to combating the effects of the gulf oil spill in coastal Alabama.

The second paper presents findings related to the wave attenuation of bagged oyster shell when used as a breakwater material. Click on either one of the images at right to download a PDF of the extended abstract.  Check back in May for a copy of the full proceedings paper.

 

Citations…

  • Webb, B. M., Douglass, S. L., Dixon, C. R. 2011. Application of coastal engineering principles in response to the Deepwater Horizon disaster: lessons learned in coastal Alabama. Proceedings of the Conference on Coastal Engineering Practice, ASCE, Reston, VA (accepted).
  • Allen, R., Webb, B. M. 2011. Determination of wave transmission coefficients for oyster shell bag breakwaters. Proceedings of the Conference on Coastal Engineering Practice, ASCE, Reston, VA (accepted).

A preliminary analysis of the data obtained during the wave basin testing of bagged oyster shell has been completed.  Forty-three experiments were conducted yielding unique combinations of structure height, structure length, and wave characteristics.  The ratio of incident and transmitted wave heights were compared to published methodologies for estimating wave transmission at low-crested rubble mound structures.  In general the equations, limits, and methodologies described in Van der Meer et al. (2005) tend to overestimate the transmission coefficients measured in the laboratory experiments, but a simple linear regression on a direct (one to one) comparison of predicted and measured values yields a coefficient of fit of 91%.

While the limited data suggests that existing methodologies for estimating wave transmission at rubble mound structures could potentially be used in the design of bagged oyster shell breakwaters, the following should be addressed through continued experimentation:

  • An expanded test matrix should be developed that includes analysis of additional monochromatic waves, as well as simulation of random waves.
  • The summative contributions of wave reflection and overtopping should somehow be segregated from actual transmission through the structure, and the overall contributions of each compared to one another.
  • The frequency attenuation of such structures, regardless of their material composition, should be explored in more detail for regular and irregular waves since wave period places an important role in sediment transport.