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

Currently seeking an MSCE student to perform research on groundwater impacts to coastal lagoons. A research assistantship is available. Contact me for more details.

Current Research Assistants

SE Students
Garland Pennison

 

MSCE Students
Patrick Hautau
Marshall Hayden
Kate Haynes
Jackie Wittmann

 

Undergraduate Students
Derek Kelly

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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waves

FHWA GI Pilot title slide... click for animation

We are wrapping up a one-year collaborative project between USA, the Mississippi Department of Transportation (MDOT), and the US Department of Transportation Federal Highway Administration (USDOT FHWA).  This was one of five pilot projects funded by USDOT FHWA to evaluate the use of green infrastructure for improving the resilience of coastal transportation systems. The pilot projects are an initial step in a more comprehensive effort by USDOT FHWA to develop an implementation guide for nature-based solutions that improve resilience. More information about that project is found at the following link {click here}.

 

Our pilot project with MDOT was focused on improving the resilience of a coastal bridge in Mississippi to hurricane hazards and future sea level rise. More specifically, our green infrastructure approach was designed to address the vulnerability of bridge approaches and low-elevation bridge spans. The causes of damage to the bridge during Katrina were determined through the use of hydrodynamic models. A hindcast simulation of Katrina was performed using the coupled ADCIRC+SWAN models. Those results were extracted and used to force a high-resolution, two-dimensional simulation using the XBeach model. An animation of some of those results is provided below.

 

To that end, a pair of vegetated berms were designed in order to mitigate storm damage now and in the future during extreme events.

 

An overview of the entire pilot project is available in a recorded webinar at the following link {click here for webinar}. Ours is the second presentation in the webinar recording (at about the 25-minute mark). Webinar recordings for all five pilot projects, as well as other presentations in an ongoing USDOT FHWA resilience series, can be found at the following link {click here for all webinars}. A brief animation of our presentation slides is available by clicking on the title slide image in this post.

 

Katrina Hindcast using XBeach, forced with ADCIRC+SWAN output…

XBeach animation

Hindcast of Katrina using XBeach: Terrain elevation contour colors correspond to the lower blue-green-brown-white color scale. Selected bathymetric contours are shown as dashed white lines on the surface. The animated water surface is contoured by significant wave height using the blue-white-red scale. Vectors represent the depth-averaged flow magnitude and direction, but only at every 1/10th grid cell for clarity.

 

boatwakestudysite-westfowlriverWe recently deployed a GoPro Hero 3 camera and two RBR D|wave gages to study boat wakes and boat traffic at a site on West Fowl River (AL) over the Labor Day weekend. The GoPro is set to capture photos every 10 s using the time lapse mode. It is wired to an external battery using the LongShot battery elimination system. The wave gages were configured independently such that one is sampling continuously and the other is processing bursts of waves every five minutes. These two sampling schemes will allow us to study the boat wake signatures in great detail (continuous sampling) and also in summary form (wave bursts). The camera system should allow us to match boat wake signatures with the vessels that generated them. While not perfect, we may also be able to estimate boat size and speed from the time lapse photos.

Here is a time lapse video (~30 seconds) of the installation at our study site…

 

 

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The Department of Civil Engineering at the University of South Alabama is seeking to fill a funded Graduate Research Assistantship for a student interested in pursuing a Master of Science in Civil Engineering degree, or a Doctor of Science in Systems Engineering, with concentrations in structural and/or coastal engineering. The initial appointment is for one year (1/2016 – 12/2016) and renewal will be contingent upon quarterly performance reviews (for up to three years ending 12/2018). The position will be competitively funded with a stipend and tuition. The qualified applicant should have an earned BS or MS degree in civil engineering by 12/31/2015, have an interest in coastal and/or structural engineering, and meet all admission standards of the Graduate School, and Department of Civil Engineering, at USA. Applicants should prepare the following materials and upload them to Academic Jobs using the link below: (1) brief statement of interest, (2) resume, (3) university transcripts, (4) a list of three references, (5) a technical writing sample, and (6) GRE and TOEFL/IELTS scores (if applicable).

Application Submission Link: https://academicjobsonline.org/ajo/jobs/5724 (click on the “Apply” link)

 

Position

 

The successful candidate will be appointed to a Graduate Research Assistant position at the University of South Alabama (USA) in the Department of Civil Engineering and will be expected to pursue a Master of Science in Civil Engineering (MSCE), or a Doctor of Science in Systems Engineering, in the specialty areas of coastal and/or structural engineering. The University of South Alabama is a public university in Mobile, Alabama and the campus is located 30 miles from the white-sand beaches of the Gulf of Mexico. The MSCE program at USA focuses on civil engineering in the coastal environment and department faculty research expertise includes the traditional areas of water resources, environmental, transportation, geotechnical and structural engineering as well as coastal engineering.

 

Research

 

The research responsibilities of the student will be to assist in a five-year funded research project focused on improving the resiliency of the built environment to disasters and natural hazards. The project requires original research, laboratory work, numerical analysis, and interpretation of results. The student will perform physical modeling of wave-structure interactions in our new 25-meter wave channel. Additional project details will be made available at an appropriate time. The ideal candidate will:
1) Have demonstrated knowledge of common numerical analysis software (e.g., Matlab)
2) Have demonstrated experience working in a laboratory
3) Have experience or the ability to learn 3D rendering software (e.g., SolidWorks)
4) Be familiar with 3D printing (rapid prototyping) and conventional fabrication techniques
5) Be physically capable of performing their duties in the laboratory facility
6) Be able to travel to meetings and conferences
7) Be legally able to attend school in the United States without sponsorship or travel assistance

 

 

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Mobile, Alabama –  The ability of communities to recover from natural and manmade disasters is strongly linked to the resilience of their infrastructure. That is why the U.S. Department of Commerce’s National Institute of Standards and Technology (NIST) announced yesterday that it has awarded a $20 million, five-year agreement with Colorado State University and 10 other partners, including the University of South Alabama, to establish the Community Resilience Center of Excellence. Click on the logo (top right of post) to link to the Center web site.

 

The goal of the Center is to develop a risk-based approach to evaluate potential strategies that improve the resilience of the built environment to natural hazards and other significant manmade disruptions.

 

The resilience tools that the Center develops will address known and frequent hazards, and gauge the ability of communities and the built environment to adapt to changing conditions and recover quickly from large-scale disasters.

 

The University of South Alabama’s Department of Civil Engineering will provide their unique coastal engineering expertise related to hurricane storm surge and waves. Drs. Bret Webb and Scott Douglass will help develop risk-based tools that address vulnerability and resilience of the built environment to coastal hazards like storm surge, waves, erosion and even sea level rise. Webb and Douglass recently authored nationwide engineering guidance for assessing the exposure and vulnerability of coastal transportation infrastructure to extreme events.

 

“With well over 50% of the U.S. population living within 50 miles of a coastline,” says Dr. Webb, who is an Associate Professor of Civil Engineering, “much of our nation’s critical infrastructure is vulnerable to coastal hazards and the expected impacts of long-term sea level rise.”

 

“What’s more troubling,” Dr. Webb continues, “is that demand in these coastal areas is increasing, putting more stress on our built environment and underscoring the need for improving the resiliency of our coastal communities.”

 

Dr. Scott Douglass, Professor of Civil Engineering, added, “Based on both experience and study, we understand that the built environment along our nation’s shorelines is highly vulnerable today, and will face increased pressures due to the expected impacts of climate change in the future.”

 

“However, the good news,” Dr. Douglass continued, “is that making our coastal infrastructure more resilient to frequent storm events today will also reduce their vulnerability in the future.”

 

With authorization from NIST to begin their efforts immediately, the multi-disciplinary research team, which also includes experts from California Polytechnic University (Pomona), Rice University, Texas A&M University (TAMU), TAMU-Kingsville, and the University of Washington, is expected to hold their first organizational meeting soon.

 

 

 

Our new wave-current channel is finally operational! We completed training and final commissioning of the facility early last week with a representative of HR Wallingford. Now we are just waiting for the surrounding renovations to be completed. Most mechanical work was completed last week and now they are fitting insulation and hanging drywall. The “flume room” and surrounding space should be finished out by the end of April. Until then, we are living in a construction area.

 

The channel’s capabilities are quite impressive. While it will likely take months to learn the nuances of our system, it is clearly capable of producing very clean waves.  The paddle’s active absorption system is really amazing and helps damp the reflected wave.

 

I have been somewhat hesitant to test the limits of the paddle, but that will surely change in the near future. The advisable limit for paddle acceleration is about 0.5G’s (4.9 m/s/s) and I think I have only tested up to about one-half of that suggested value.

 

So far I have experimented with the spectral, regular, and solitary-type waves. I was even able to generate a fairly steep wave that broke (spilling) off the paddle. The video below shows a low-amplitude (<10 cm), 2-s-period wave. Click on the triangle to play the video.

 

More updates coming soon, as well as an exciting announcement that may give  you the opportunity to come visit ‘South and see  our new facility first-hand!