For the sixth consecutive year, I had a lot of fun attending the ASCE/AISC National Student Steel Bridge Competition (#NSSBC)—this year hosted by University of Akron on May 23 - 24, 2014. The competition provides an applied learning challenge for students’ skills in structural design, fabrication processes, construction planning, and project management.
I continue to be impressed by the balance of hard work, hands-on learning, and fun that this competition poses for all the participating ASCE steel bridge teams!
Bentley is pleased to continue as a national sponsor, providing not only financial support, but also free software (STAAD.Pro V8i & Structural Synchronizer V8i) and supporting tutorial materials to all participating teams in the fall (see my 2014 NSSBC sponsorship blog). It was great talking to so many teams about how they put STAAD.Pro to good use in their bridge design and analysis!
The rules of the Student Steel Bridge Competition change annually, simulating a request for proposal and resulting in a 1:10 scaled steel bridge model to demonstrate the merits of the design. This year’s problem statement involved a request for design/build proposals for a replacement to an eighty year old timber trestle carrying an essential spur of a railroad. Mandates included minimizing disruption of ongoing railroad activities, and accelerated bridge construction. The narrow railroad cut limits size and weight of both materials and equipment, and the topography limits the location and size of the staging area. Meanwhile, the state Department of Natural Resources will not approve permanent piers in the river, and requires adequate clearance to allow for extreme high water.
208 teams from the United States, Canada, Mexico and China competed in the 2014 Student Steel Bridge Competitions, held during regional ASCE Student Conferences. 49 teams moved on as 2014 National Student Steel Bridge Competition qualifiers!
Friday May 23rd was devoted to registration, bridge set up and display judging. This day encourages mingling of the teams, while they size up their competition.
The real action got underway on Saturday, May 24th, with the construction competition, involving timed builds and structural testing.
The designated builders from a given team must place each individual tool and component (literally, bolts and all) in the staging area. The goal is to have the fastest build time and lowest building cost, so strategy is important. While more team members increase construction speed, they also add onto construction costs. While the judges watch carefully, the builders race the clock to construct their bridge from scratch—while attempting to avoid any penalties. One piece at a time, students run components of their bridge over to the builders, who scramble to construct their bridge as quickly as possible.
This year, the fastest time was posted by Clemson University, at 5.88 minutes
After the judges evaluate the construction of each bridge, deem it sound, and record the official time (adding any penalties), each team moves their bridge to the Load Testing station.
First, the students apply a standardized lateral load test. Decking is placed at the center of the span and 75 pounds are added to the decking; a 50 lb. lateral pull is applied, and the sway must not exceed 1 inch.
Presuming the lateral load test is passed, each bridge proceeds to the vertical load test.
Two sections of decking are added at specified locations, and three targets measure vertical deflection.
100 lbs preload are added to one decking unit, and then another 50 lbs are added.
150 lbs are loaded on the other decking unit, and gradually a total load of 2,500 pounds is applied to the bridge.
Sway cannot exceed 1 inch, and deflection cannot be more than 3 inches downward on any target.
These tests are designed to be rigorous, because the rules simulate the same requirements that dictate the design and construction of full-scale bridges, including standards for strength, durability, constructability, usability, functionality, and safety.
Each bridge is ultimately judged on the following categories: display, construction speed, lightness (lowest total weight), stiffness (lowest aggregate deflection), construction economy (lowest construction cost), and structural efficiency.
And now what you’ve been waiting for (if you haven’t already seen our posts on Facebook on Saturday)…. This year’s winners are:
1st place: University of California, Davis
2nd place: Massachusetts Institute of Technology
3rd place:. University of California, Berkeley
Congratulations to all of the participating teams, for jobs well done!
You can read more about this competition at http://www.aisc.org/steelbridge, and see full results at www.nssbc.info