Tassin D.,CA Technologies |
Hall C.,CA Technologies |
Malone P.,PCL Constructors Inc.
3rd International fib Congress and Exhibition, Incorporating the PCI Annual Convention and Bridge Conference: Think Globally, Build Locally, Proceedings | Year: 2010
Elevated light rail mass transit systems provide a safe and efficient means of transportation in many major cities throughout the world. In several cities where traffic congestion is particularly severe, systems that were initially intended to be alternative means of transportation have become the primary means of commuter transportation. As light rail lines are typically considered in metropolitan areas, available corridors are usually located in congested urban areas and often in environmentally sensitive areas. Adding to these constraints are the public's desire for attractive structural designs and the need for rapid construction to minimize impact on already congested transit corridors that the proposed mass transit lines are aiming to relieve. A break-through design that efficiently meets these numerous bridge design challenges was recently completed for the Seattle area. An initial 22.5 km corridor of dual-track light rail connects Downtown Seattle with the Seattle-Tacoma (Sea-Tac) Airport, and opened in July 2009. For one portion of this route through the city of Tukwila (Contract C755), Sound Transit decided to construct an elevated guideway. The purpose of this paper is to discuss the unique design features of this elevated guideway that address many of the challenges faced by transportation authorities considering mass transit.