Design of a Sealed Expansion Joint for the Third Lake Washington Bridge
S. Brown and U. Haerle
Appears on pages(s):
bearings; bridges (structures); control joints; floating bridges; plastics, polymers, and resins; structural design; Design
The Third Lake Washington Bridge floats between Seattle, Wash., and Mercer Island on Lake Washington. The length of this structure is approximately 2« miles and because this structure floats, it is subjected to the rise and fall of the lake water level and wave action. The result is a complexity of movement. These movements are 48 in. (1219 mm) longitudinally, The vertical deflection is 2 deg or 15 in. (381 mm) across the joint system, and the horizontal or transverse rotation is 1 deg. These parameters initiated the most sought-after design competition for a sealed expansion joint in history. Three alternate designs were proposed. The State of Washington's Department of Transportation Bridge Design Group selected a joint venture in which the authors participated. This paper discusses the movements of the bridge and the design of the selected expansion joint system.