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Bridge engineering is dominated by bespoke design, where new solutions are sought for each site. Despite potential cost and time savings, modular technologies are rarely pursued. To serve as inspiration for innovation in modular technologies, this paper presents a historical case study of the Système Eiffel – a modular, steel bridge system based on repeated triangular modules or elements used throughout the world. While Gustave Eiffel was widely known for his great iron bridge designs in Europe, his contributions to modular and rapidly erectable bridges are less known. This paper presents his system, including 1) the reasoning behind the design as described in documents by Eiffel, 2) a description of the structural system of one bridge type, including detailed plans and the erection strategy (i.e. launching), and 3) a catalog of the other bridge types that included minor variations. While this paper is historical in nature, it highlights an innovative, modular approach to bridge design that was appropriate at a particular moment in history and aims to spark innovation in bridge engineering today.
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This content will become publicly available on March 1, 2026
Behavior of incrementally launched modular steel truss bridges
This paper presents a numerical investigation of the behavior of steel bridges composed of modular joints during erection by incremental launching. The modular joint is a nodal connector made up of flat and cold bent steel plates that are joined to standard wide-flange members to form a truss-type bridge. Members and modular joints have flanges and webs that are connected independently by bolted splices, resulting in moment-resisting connections. This capability of the nodal connectors to transmit flexure enables a truss-type system to be incrementally launched and provides enhanced resiliency through system redundancy (i.e., the structure can tolerate the loss of a diagonal member). This paper specifically investigates logistics related to this kit-of-parts approach, focusing on transportation to site, “shaking out” of the steel components for erection, and erecting components while minimizing the need for high-capacity cranes. A high-fidelity, three-dimensional Finite Element (FE) model using shell elements that incorporates staged construction is used to understand the behavior of a 119-m (390-ft) two-lane vehicular bridge during incremental launching and in service. The focus is on evaluating the global behavior of the system and local behavior of the modular joints and the members. Results demonstrate the erection advantages of this novel modular approach. The detailed FE modeling approach is compared with a design-level model using frame elements, culminating in guidelines for design and analysis.
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- Award ID(s):
- 2044340
- PAR ID:
- 10571542
- Publisher / Repository:
- Elsevier
- Date Published:
- Journal Name:
- Engineering Structures
- Volume:
- 326
- Issue:
- C
- ISSN:
- 0141-0296
- Page Range / eLocation ID:
- 119509
- Subject(s) / Keyword(s):
- Modular construction Accelerated bridge construction Incremental launching Steel truss
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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