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TEEX Bridge Maintenance Tour

4/1/2008 12:00 AM

The Bridge Maintenance Course offered the Texas Engineering Extension Service (TEEX), a member of the Texas A & M System, trains public works employees how to perform bridge inspections and maintenance operations—two tasks vital to ensuring the safety of our nation’s bridges. So when TEEX discussed creating a build in Second Life to support their existing training programs, staff members thought a bridge maintenance tour may be a good start. “We wanted to make something that would be of real benefit to those that would visit the build, and could be of interest to a variety of visitors,” said James Matney, project manager for TEEX—also known as TEEX Clary in Second Life (SL). “Because of recent incidents within the U.S., we thought providing information on common bridge concerns would be a welcomed build.”

Because TEEX has six other divisions with training in related areas, the staff had considered other types of builds. “Initially there was the idea of creating a virtual version of our famous Disaster City and Brayton Firefield training areas,” said Matney. “These would have potentially provided some aspects of virtual training in search and rescue, and firefighting. Also, it would have allowed for a virtual tour for these often ‘off-limits’ facilities. But, the fact that TEEX’s entry into SL coincided with the creation of Public Works island presented an ideal opportunity for TEEX to contribute to what is already a great fixture in SL.”

CONSTRUCTION BEGINS

TEEX Clary began construction of the Bridge Maintenance Tour in October 2007 on the Public Works sim, an island in Second Life established to provide a resource for public works professionals and engineers. “This is TEEX’s first build, and the bridge is convenient in its relative simplicity,” said Matney. “Building the bridge was a learning process that started with large prims. Then development of the informational station podiums provided for some experimentation with basic sculpted prims and scripts for interaction. I can see future builds being more complicated, detailed, and interactive, whether we develop more skills in-house, or by outsourcing to professional developers.”

As Matney planned his SL build, he faced the initial frustration felt by most who are familiar with popular modeling programs—there is currently no easy way to import CAD files into SL. “First, we planned to use a previously developed 3-D model of a newly built local bridge as a benchmark for the build, but we did not have an easy way to import the model. However, the bridge’s parts were very simple to rebuild in SL.”

Once the bridge was in place, Matney started to place information stations at specific bridge elements. “We used our Bridge Maintenance flier for content,” said Matney. “When we had a couple stations ready, the bridge was reviewed by our bridge maintenance expert , Ralph Banks, P.E., TEEX adjunct instructor for bridge maintenance.” Banks made sure that specific components were focused upon. “Examination of a typical roadway bridge structure for maintenance issues usually requires a methodical and relatively comprehensive onsite, sequential examination for maintenance needs of the bridge’s various components and their parts which are referred to as elements,” said Banks. “ Most bridges consist of deck, superstructure, substructure, approaches and channel components, with many different maintenance issues possible within each component.”

Matney and Banks decided to use a notecard distribution system to convey information. “To develop the information, Banks reviewed a slideshow presentation with a number of the core bridge maintenance issues,” said Matney. “From there we tried to incorporate as many of the reviewed issues as possible. Most of the stations include a button that demonstrates what needs to change in order to keep the bridge best maintained.“

FINAL REVIEW

After Matney completed the build, Banks provided a final visual review. Matney said, “He suggested corrections in some areas, including slight changes with the bridge marker signage, and changes in the bridge’s drainage to make it more authentic and applicable for what it was intended to demonstrate.“

Communications director, Jay Socol, provided a final review of the notecard information. Once those text changes were made, the bridge was officially “open.” Socol and Matney introduced the bridge maintenance tour sim to their public works director and some other folks at TEEX. “They asked a ton of questions, but not in a negative way,” said Socol. You could tell that they were trying to fully gauge the potential of this newly revealed tool. The wheels are twirling in their heads—it’s only a matter of time before we shift our SL walk into an SL jog.”

Socol would like to see the build generate interest in the real life course, “Routine and Preventive Maintenance of Bridges,” that is offered by the Engineering, Utilities, and Public Works Training Institute (EUPWTI) division of TEEX through the federally funded Local Transportation Assistance Program, or LTAP. “I want this information to reach new people. I’d like it to result in people taking our bridge maintenance course or investigating other training made available by TEEX,” said Socol. “Internal to TEEX, I’d like our other operating divisions—fire, search/rescue, law enforcement, etc.—to be excited about it enough to seek our help in finding their own presence in SL. That’s when I’ll know we’re succeeding.”

Matney also sees the SL bridge tour as an opportunity for TEEX to participate in keeping people in general informed on concerns in their community. “We can also use the bridge as a guided tour of issues for county officials and engineers. Eventually, the bridge could be used within actual lectures and classroom training.”

The TEEX bridge is SL is modeled after a real life bridge that crosses a state highway across a small stream. It consists of two simply supported precast, pre-stressed concrete I-shape, multiple girder spans. In addition to the two end abutments, the bridge is supported by an interior substructure support (bent) consisting of three equally spaced, vertical cast-in-place, round concrete piling (called drilled shafts) topped with a horizontal cast-in-place crossmember called a bent cap.

The end abutment supports are of design similar to the interior support, including bent caps, only the vertical cast-in-place piling are not visible due to the presence of earth slopes at the abutments which are further paved with cast-in-place concrete slab slope protection.

The ends of each of the longitudinal superstructure girders rest on rubber-like, elastomeric pads (called bearing pads) that in-turn, rest on the abutment and interior support bent caps. These elastomeric pads through stretching or otherwise deforming, enable the spans to elongate with warmer weather, then contract during cooler weather, without structural damage to the bridge or pads themselves.

The roadway deck of the bridge consists of a lower portion of flat, pre-cast, pre-stressed concrete panels, with the upper portion of the deck being cast-in-place dense concrete. The lower portion panels of the deck also served as stay-in-place forms for the deck system during construction. The bridge railing along either side of the roadway is of cast-in-place concrete construction that has been engineered to retain most impacting errant passenger vehicles within the roadway, with minimum injury to vehicle occupants, and minimum damage to the vehicle and the bridge itself. Transverse, expansion joints, are provided at both extreme ends of the bridge roadway to accommodate the natural expansion of the bridge during warmer periods of the year. These joints have further been provided with seal elements to avoid drainage from the roadway flowing down through the joint openings. This drainage could eventually prove harmful to other structural elements underneath the deck.

The bridge approaches consist of cast-in-place approach roadway slabs to enable smoother entrance onto the bridge, as well as smoother exits away from the bridge. Approach rail has been provided along either edge of the approach roadway, which has been connected structurally with the bridge rail ends to enable any impacting errant vehicle to slide along the combined connected together railing and slow velocity. The extreme ends of the approach railing away from the bridge proper are protected with impact attenuation devices to minimize the crash effect to any impacting errant vehicles.

Contact Information

Kathy Fraser

Associate Director of Marketing and Communications

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A member of the Texas A&M University System
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