The 2024 AISC/ASCE Student Steel Bridge Competition requires students to design, fabricate, and construct a scale model of a steel bridge that will serve the disc golf community in Lincoln Parish Park in Ruston, Louisiana. Following the 2024 AISC/ASCE Student Steel Bridge Competition design specifications, 5 total design alternatives were proposed: two under trusses, an over truss, and two beam trusses. Visual Analysis 21.0 was used to analyze each alternative and determine the vertical and lateral deflection, weight, and stresses of all the designs. The alternatives were analyzed using a decision matrix that accounted for constructability, weight, load uniformity, and deflection, which contribute to the competition scoring criteria. A single span beam-truss was selected as the final design, consisting of 43 members and 76 connections. The bridge was 20’-3” long, with a height of 1’-11”, and an approximate weight of 244 pounds. Various member sizes of strength ASTM A513 were used in fabrication, including 1”x1”x11 HSS square tubing for the stringers and footings, and 3/4”x0.125” wall tubing for the diagonals. Members were connected in the top and bottom cords through plate and pivoting connections and double shear hinge-like connections respectively. The bridge was constructed at the Regional Competition at Stony Brook University in April 2024 where the team was awarded 1st place in aesthetics as well as 3rd place overall. The total engineering services cost for the fall, winter, and spring semesters was $140,000. The construction cost estimate was $5,400, and the total competition construction cost according to the ASCE/AISC Steel Bridge Competition Guidelines was $24,611,000.
Fall Semester Summary
The fall semester started off with fundraising for the upcoming year. Research was then done on possible designs of the bridge when the rules were released. Referring to the research, 5 different alternative designs were then made, consisting of an over-truss, 2 under-trusses, one Howe truss, and one beam-frame design. These designs were then placed into Visual Analysis, to make a prediction for the deflection under all 6 possible load cases. The final design was an edited version on the beam-design, prioritizing construction time and structural efficiency. Connections were then designed, consisting of single and double shear bolted connections in the x, y, and z axis’. Materials for the final designed were then ordered from Alro Steel, consisting of the previously mentioned HSS, tube, and plate sections. Fabrication was then started when the materials arrived, consisting of cutting the HSS and tubing material. This was based off the developed CAD drawings that was done by the team.
Spring Semester Summary
During the spring semester, the bridge was fabricated and constructed. The fabrication consisted of in house use of the Water Jet, Milling Machine, Belt Saw, and MIG Welder. All labor was done by the 5 team members. After the bridge was then fabricated, construction practice then took place. The team showed constant improvement in construction; while starting off at 35 minutes in construction, they were able to improve down to 14 minutes of construction in practice. The team then prepared going to competition by making a poster, painting the bridge, and adding a TCNJ emblem on the South Footing. At the competition, the Steel Bridge team competed in all events and ended up placing 3rd place overall, behind NJIT and NYU. The team also finished 1st place in Aesthetics, 3rd place in stiffness, 3rd place in structural efficiency , 3rd place in lightness, and 1st place in construction noises. The team was very happy with their results, and then documented their process and gave advice going forward for future teams. The presentation for this is found in this link.
https://drive.google.com/file/d/1MvhRxARzELEsbSSQ9sv3dMly-DCaevNB/view?usp=sharing
