Introduction

Introduction

The Short Span Steel Bridge Alliance is a group comprised of manufacturers, fabricators and representatives of related government organizations and associations who are stake holders in short span steel bridges. The main focus of the group is to increase awareness of the unique benefits, cost-competitiveness and safety facts involved with the use of short span steel bridges in spans used in installations up to 140 feet. [5]

The Short Span Steel Bridge Alliance presents short span steel bridges that can be built quickly, using local crews and often can be designed with prefabricated elements which provide a simpler installation and cost savings. A table from a Short Span Steel Bridge Alliance brochure, presented in Figure 1, presents a summary of the types of steel superstructures that can be applied to all bridge spans included in the short span range. [5]

 

 

 Figure 1 Table of Steel Structures for Short Spans [44]

The Federal Highway Administration (FHWA) has recently developed a program that they have titled Highways for LIFE with the word "LIFE" being an acronym for:

  • Long Lasting
  • Innovative
  • Fast Construction
  • Efficient

The Highways for Life program has the motto of "Get In, Get Out, and Stay Out". This motto reinforces the idea of quickly constructing quality bridges that are sound enough to not need extensive attention throughout the remainder of its life span. Modular Bridge Technology is one solution that can aid in reaching these goals of overall better bridge design and construction. [12]

Several methods of Modular Bridge Technology are currently in use to build better quality bridges faster. The use of these different methods applies to all of the different sectors of bridge design and construction. Modular Bridge Technology has been applied to the substructure, superstructure and deck systems of existing bridges with positive results. Some may not know all of the applications that have been used and tested. [12]

The use of Modular Bridge Technology is more than just a way to improve the efficiency of bridge design and construction. There are also the added benefits of: Improving bridge site safety, Lessening the disruption of traffic during construction, Improving the quality of construction and Reducing environmental impacts and life cycle costs. [12]

At the suggestion of the Federal Highway Administration, a Technical Working Group was established to review the various options available for short span modular steel bridge construction. The Technical Working Group consists of representatives from industry associations (including the Short Span Steel Bridge Alliance), steel bridge fabricators, university faculty members, steel manufacturers, State Departments of Transportation representatives and government organizations (FHWA).

Overview

The mindset of Modular Bridge Technology has been applied in multiple ways to increase the efficiency of the design and construction of different bridge elements. These applications have been applied to the different parts of bridges including: substructure, superstructure and decking. There are also Modular Bridge Systems in use that combine some of the previously listed bridge sections. This type of system may include a section of bridge that can be installed that provides normally separate parts of a bridge already assembled. An example of this would be an element that is transported to the bridge site and makes up both the superstructure and decking surface of the bridge. More recently, equipment has been developed specifically to transport and install prefabricated bridge sections.

This report will cover several different Modular Bridge applications that are being used in bridge design and construction today, specifically in the field of short span steel bridges. The report will provide description, illustration, and evaluation of each of these methods, allowing the reader to become more aware of the overall benefit of using Modular Bridge Technology.