Railway Interchange 2017 Buzz

Innovative Foundations for a Caustic Environment (Room Sagamore 2)

19 Sep 17
3:00 PM - 3:30 PM

Tracks: AREMA Full Schedule, AREMA Technical Sessions- Structures

The Great Salt Lake is crossed by the 20-mile-long Causeway constructed by the Southern Pacific Railroad in 1902. At that time, the Causeway consisted of two rock fill causeways connected by a 12-mile-long wooden trestle. The trestle was eventually replaced by a Causeway extending the entire length. The Causeway construction included pushing rock from west of the Salt Lake across the lake. The rock continues to settle into the very soft lakebed even a century after the initial construction. Over the past half-century concrete culverts were installed through the causeway. The culverts were intended to allow water to circulate from the North to South of the Causeway. Rather than only allowing the water to pass through the porous Causeway. The culverts later deteriorated and failed as they sank, along with the Causeway, to the bottom of the lake. Due to third party stake holders, the sensitive ecosystem of the Great Salt Lake, and economic impact on the state of Utah; the UPRR elected to provide a means for water circulation from the North side of the lake to the south. UPRR Design Staff worked with the Army Corps of Engineers, as well as a team of third party stakeholders, to find a structure that would balance the transportation needs of the railroad, as well as the ecological and economic concerns of the other stakeholders involved. Bridge plans were developed to provide an opening across the Salt Lake Causeway. Extra care was utilized in providing a foundation that could be constructed through the rock of the causeway, take up pile loads in the bottom of the Great Salt Lake, and withstand the corrosive environment of the salt laden water contained in the Great Salt Lake. The bridge would be constructed with minimal disruption to RR operations, as well as third party stakeholders that also utilize the Causeway for access. This paper will discuss the history of the Salt Lake Crossing. The authors will also describe the design of the foundations and the construction techniques utilized to install the bridge under the adverse working conditions on the Great Salt Lake. Care will be taken to describe the planning process, the teaming required to receive permits, and the buy in from all Stakeholders.