ASCE Steel Bridge

Completed by RSJ Steel Bridge Company

NAU Capstone Senior Design Project 2007

 

 

 

 

Rafael Davis

Team Leader:

Rafael is a senior in Civil Engineering with an emphasis in structures.He organized team meetings and acquired materials.Rafael campaigned to get donations from Schuff Steel and Copper State Bolt and Nut inc.Other duties included getting registration for the competition completed and

Jacob Morin

Lead Design Engineer

Jake is graduating in May Magna Cum Laude with a degree in Civil Engineering.†† Jake ran design meetings and kept the project on schedule.Jake was instrumental in the project in problem solving and keeping the team motivated. Jake developed the construction assembly and organized assembly practices.

Stan Tallman

Fabrication and Construction Engineer

Stan is graduating in May with a degree in Civil Engineering.Stan had the most construction and welding experience so he volunteered for the position.Stan instructed the team on the use of tools such as the plasma cutter, welder, and grinder.Stanís experience was critical in reducing the number of mistakes and rebuilds for projects.

Pictures from project:

  • Fabrication
  • Assembly Practice
  • Competition Assembly
  • Competition Loading

 

 

Project Description

 

 

 

 

Students were selected to design and build a steel bridge to compete in the ASCE competition. The bridge is built by the students but they may seek advice from faculty and other consultants. Standards for strength, durability, constructability, usability, functionality, and safety reflect the volumes of regulations that govern the design and construction of full-scale bridges.

 

 

 

 

Problem Statement

 

It was requested by the DOT that a 1:10 scale model be constructed to represent the design/build concept. The model represents a bridge that serves the needs of residences, farms and agricultural processing industries that are the economical base for this rural region. Models will be erected under simulated field conditions and load tested. The bridge must be able to carry specified patterns of loads without exceeding sway and deflection limits. The contract will be awarded to the company whose model best meets the DOTís needs and requirements.

 

Decision Matrix

Standard

Arch Bridge

Truss Bridge

Simple Beam

Ease of Construction

3

5

8

Ease of Analysis

5

5

6

Estimated Weight

3

6

8

Estimated Cost

2

6

6

Total

13

22

28

 

Based on the decision matrix, the simple beam design outweighed the arch bridge and truss bridge. Therefore, it was decided that the proposed scale model have the characteristics of a simple beam. Initially, it was assumed that torsional stresses from eccentricity will cause the bridge to twist. To counteract the torsional stresses two steel straps were cross braced between the vertical members. After laboratory tests were performed it was determined that the strap steel failed due to buckling. The design was reevaluated, and it was decided that cross members placed between the vertical members would be more beneficial in transferring load to the columns supporting the bridge.CAD drawings are provided in the link below of this design. Pictures of the completed product are at the top.

Link to CAD drawings