EMMA

EMMA is a six-metre-span steel truss bridge designed and fabricated for the 2022 Design & Construct (DE&CO) International Steel Bridge Competition. The project explores a balance between aesthetics, cost and structural displacement. Different bridge alternatives were evaluated against these three criteria to arrive at the final structural arrangement.

The name EMMA combines the initials of the four team members. This collaborative approach extends from the analysis model to workshop fabrication, connection details and assembly at the competition.

Structural System

Four inclined supports and two main beams define the bridge deck. Cross members between opposing beams are arranged to transfer loads and control lateral movement. Bracing between the supports also addresses lateral translation. SAP2000 analysis was used to evaluate moment effects in the supports.

Diagonal members from both directions meet at the midpoint at a height of 1.90 metres. The central members connecting the upper truss to the deck are designed to act in tension. A maximum member length of 1.20 metres informed the layout of the deck bracing and its connections.

Materials And Connections

ST-37 steel and a truss arrangement were considered together to develop an economical structural solution. Rectangular profiles were selected for the supports and main beams, with tubular sections for the deck members and upper truss. The proposed sections are 50 × 50 mm for the supports, 30 × 50 mm for the main beams, Ø30 mm for the deck members and Ø40 mm for the upper truss.

Although some connections are welded, the system relies primarily on bolted joints. The design document specifies M8 bolts for the deck cross members and M10 bolts for the other members, both in strength class 4.8, based on the connection calculations.

Form And Colour

The four inward-inclined supports define the bridge’s character. Their geometry was considered both for its visual expression and its intended contribution to lateral-load behaviour. MEF University’s identity colours distinguish the structural elements: red supports and main beams, white bracing and a blue upper truss.