May 05, 2000 09:00 ET|
Southwest MSRCD Announces 8th Annual Timber Bridge Competition Results
BROOKHAVEN, MS--(May 05, 2000) - Southwest Mississippi Resource Conservation and Development Council, Inc. today announced the results of it's 8th annual National Timber Bridge Competition.
Eleven teams of students from ten universities across the US matched wits to devise a better way to "cross the creek" during the National Timber Bridge Design Competition. Open to student chapters of American Society of Civil Engineers (ASCE) and Forest Products Society (FPS), the competition was made possible by a grant from the US Forest Service through its Wood In Transportation Program. Additional financial support was provided by the Southern Pine Council of the Southern Forest Products Association, Unit Structures LLC, and Willamette Industries. Southwest Mississippi Resource Conservation and Development (RC&D), Inc., coordinated the competition, with the Civil Engineering Department at Mississippi State University providing technical assistance.
Each team designed, constructed and tested their bridges on their home campus, then submitted documentation of their activities and results to a panel of judges for review. The competition is conducted online via the Internet. Each team is required to post design drawings, test results, and project highlights on the Web at http://southwest.msrcd.org/timberbridge. Click on "2000 Competition Results" to view details of competition results and to access each entry in its entirety.
Winner of the Best Overall Design Award sponsored by Willamette Industries was Virginia Tech Forest Products Society. Their design featured a pair of longitudinal glu-lam beams supporting a transverse deck of 3/4-inch CCA-treated southern yellow pine, each centered over transverse floor beams of 2 x 4 SYP, essentially forming a continuous series of transverse T-beams. In turn, two tapering, glue-laminated, yellow poplar arches supported the entire structure. Both the arches and the longitudinal stringers incorporated carbon fiber strips between the laminations in regions of highest tension forces. The bridge used no metal fasteners, only resorcinol/phenol formaldehyde adhesive, carbon fiber and wood. This entry also placed first in Best Support Structure, Best Deck and Most Innovative Design.
San Francisco State University's ASCE chapter was the second highest prize-winner, capturing second place in Best Overall Design and Best Support Structure and third place in Most Aesthetic Design and Most Innovative Design with their built-up laminated arch structure.
Clarkson University ASCE won the most Practical Design while California State-Fresno captured first place for Most Aesthetic Design. Other teams winning awards were Lawrence Technological University ASCE (3rd-Best Support Structure), Clarkson University ASCE (3rd-Best Deck), Washington University of St. Louis ASCE (3rd-Most Practical), Merrimack College ASCE (2nd-Best Deck), University of North Carolina at Charlotte ASCE Team 2 (2nd-Most Innovative) and Oregon State University ASCE (2nd-Most Aesthetic and 3rd-Best Design). Also competing were University of Louisiana at Lafayette-ASCE and University of North Carolina at Charlotte ASCE Team 1.
For a complete review of Competition Results and each individual entry, go to http://southwest.msrcd.org/timberbridge and follow links. Results of 1999 and 1998 competitions are also still posted online. Rules for the 2001 competition will be posted online by mid-September 2000. For additional information contact Southwest Mississippi RC&D, Inc., competition coordinators at email@example.com.
The competition's objectives are to promote interest in the use of wood as a competitive bridge construction material, to generate innovative and cost-effective timber bridge design techniques, and to develop an appreciation of the engineering capabilities of wood among future transportation and forest products engineers. Following the competition, most of the bridges were placed into actual use on campus walkways, golf courses, cross-country tracks, park trails, etc.
The test bridges were 10.8 feet long and 4.6 feet wide and were loaded with a test weight of approximately 4,500 pounds. Average weight of the bridge models was 249 kg. At full loading, maximum bridge deflection ranged from 1.40 mm to 4.85 mm. Maximum allowable deflection was 8 mm. Net deck deflection for the nine bridges that met the maximum allowable deflection of deck span divided by 400 averaged 45% of maximum allowable. Percent non-wood materials in the bridges averaged 9%; maximum percent non-wood materials allowed was 25 percent, by weight. A total of 98 students spent 4,930 hours on the competition, competing for $10,000 in prizes. Judges were Greg Jones, Willamette Industries; Dr. Ralph Sinno, Mississippi State University; and Marshall McLaughlin, USDA-Natural Resources Conservation Service.
Bennie F. Hutchins