On May 22-23, University of Missouri, Kansas City acted as host for the 2015 ASCE/AISC National Student Steel Bridge Competition.




The competition aims to reinforce engineering education via a comprehensive, real-world student project that runs from structural design through fabrication, construction planning, and testing. Teamwork and project management are key to success in this intercollegiate competition, to produce a scale model that satisfies all requirements in the categories of stiffness, lightness, construction speed, display, efficiency, and economy.

Bentley is pleased to continue as a national sponsor for the seventh year, providing not only financial support but also free software (STAAD.Pro V8i  &  Structural Synchronizer V8i) and supporting tutorial materials to all participating teams (see my 2015 NSSBC sponsorship blog). I always enjoy attending the national finals, and talking to teams about how they leveraged STAAD.Pro 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 involves a request for design/build proposals for a bridge over a river in a tropical country, to relieve poverty by improving commerce between farming villages and the capital city. Many challenges are involved: the site is accessible only by trails that are impassible during the rainy season, material transport must be limited to sizes small enough for ox carts, and it would prove uneconomic to place piers either in the river or in the surrounding floodplain due to a deep layer of organic soil. Accelerated Bridge Construction (ABC) is key to completion within a single dry season, but low water levels during the period preclude the use of construction barges; only a temporary causeway can be utilized to assist during construction.

Hundreds of teams from the United States, Canada, and Mexico tackled this design challenge and competed in the 2015 Student Steel Bridge Competitions, held during regional ASCE Student Conferences. 47 teams earned an invitation to the national finals as the 2015 NSSBC Qualifying Teams.

Friday May 22nd is devoted to registration, bridge set up and display judging. The opening day encourages mingling of the teams, while they size up their competition.





The main event starts on Saturday, May 23rd with the construction competition, which involves timed builds and structural testing. First, the designated builders from a given team must place each individual tool and component 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 increase construction costs.




While the judges watch carefully, the builders race the clock to construct their bridge—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 construction speed was achieved by SUNY College of Technology at Canton, at 4.00 minutes; their time was 1.88 minutes faster than last year’s top speed!


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 first Load Testing station. There, 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 at deck level, and the sway must not exceed 1 inch.


Presuming the lateral load test is passed, each bridge then proceeds to the vertical load test. Two sections of decking are added at specified locations, and three vertical deflection targets are set.



50 pounds preload are added to each decking unit, and then gradually a total load of 2,500 lbs 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.

Without further ado (if you haven’t already seen our posts on Facebook)....

The winners of the 2014 ASCE/AISC National Student Steel Bridge Competition are:

1st place: University of Florida


2nd place: California Polytechnic State University, San Luis Obispo


3rd place: École de technologie supérieur


Congratulations to all of the participating teams, for jobs well done!

You can read more about this competition at http://www.aisc.org/steelbridge, see full 2015 results at www.nssbc.info  and see some more images at 2015nssbckansascity.shutterfly.com.

 

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