The Utah Department of Transportation (UDOT), in coordination with Bluffdale City, identified a need to construct an east-west route that would become a major artery and connect various roadways in the area including I-15, SR 68, and Mountain View Corridor.
“The bridge is at an in between point between two counties – Salt Lake County and Utah County,” says Jennifer Fowler, a Project Public Information Team Member for The Langdon Group. “Both counties have seen a boom in growth and there has been increased development, such as tech centers and office buildings, along I-15 which is a main artery in the state.” Population growth is expected to continue in both counties while development in Bluffdale City is rapidly expanding. All of this has led to a choke point going east and west in the area."
The main element of the project is a 435-foot-long, two-span, five-lane bridge that will connect the adjacent Porter Rockwell Boulevard segments. The bridge spans over the South Jordan Canal, Jordan and Salt Lake Canal, and the Utah Transit Authority and Union Pacific Railroad tracks at a height of over 40 feet above the Jordan River.
Other major elements of the project include a realignment of the Jordan River Trail, relocation of the Jordan Valley Water Conservation District water line, two canal box culverts, a multi-use trail, and a roadway connecting the adjacent Porter Rockwell Boulevard segments.
“There are heavy dense boulders in the area that could be as big as 3 to 5 feet, aggregate pits, and a quarry,” says Jon Lowe a Design-Build Project Manager with Ralph L. Wadsworth Construction Company (RLW) which serves as the contractor on the project. “You are at the will of what you are diving into.”
Access has also been a challenge. Wadsworth had to construct several temporary roads just to access the areas where several of the structures had to be built, as well as build a canal, all while avoiding damage to any existing utilities. The existing roads that were in the area were not wide enough to transport construction equipment to the site.
On top of the issues related to the terrain, the location is a high seismic area. “Performance and durability are a paramount concern because of the challenges the area presents,” says Derek Stonebraker, a Program Management Project Manager for Horrocks Engineers. “The way UDOT manages long term maintenance needed to be taken into consideration.” One such consideration is the use of weathering steel girders which offer long term protection from corrosion and eliminates the need for future painting.
A segment of the trail is being rerouted and built as part of the bridge to connect to the Jordan River. The trail could not be permanently closed during construction, so “we had to manage the people who frequent it,” Lowe says.
A primary concern on this project was minimizing impacts to the existing canals and the Jordan River due to construction activities. “We wanted to eliminate the need for a cofferdam and avoid impacting the Jordan River which flows year-round,” Lowe says.
To accomplish this, Wadsworth installed four drilled shafts along the west bank of the Jordan River, which required a unique Hydraulic Casing Oscillator used to drill 8-foot diameter holes up to 87 feet deep. The casing was then cleared using a spherical hammer grab.
The team used oversized drilled shafts with tip grouting to optimize capacity of the shafts. There were other benefits. “The design-builders bridge optimization and foundation approach resulted in cost savings as it allowed them to drill two fewer shafts, which means less risk to workers and impacts to the adjacent canal and river,” Stonebraker says.
The two cast-in-place concrete box culverts carrying water for local canal companies under Porter Rockwell Boulevard also presented challenges. Due to the existing topography and the finished grade, one of the culverts had to be constructed with over 40 feet of fill.
Coordination was also a challenge, yet it was imperative to ensure the construction schedule could be met and the culverts could be built without impacting the various irrigation seasons serviced by the canals.
Three canals were shut down for annual maintenance from October 15 to April 1 during which the team had to install the two box culverts in and have them ready to receive water. Plus, there was the central water line for the Jordan Valley Water Conservancy District. “There was a 14-day shutdown during which we had to tie into the water line,” Lowe says. The team accomplished this in 10 days.
The project is currently on budget. “RLW offered a bid that was under what UDOT expected and their innovative design reduced the size and number of drilled shafts and shortened the bridge,” says Allen. “They’ve also been good at handling curve balls.”
UDOT decided to use the design-build project delivery method because it encourages collaboration on project design and innovation and efficiency at all phases of the project.
The project began in the fall of 2020, and the anticipated completion is spring of 2022. Despite the challenges brought on by COVID-19 – as well as dealing with the various utilities and railroad companies – the project is on schedule. “A big part of the success was meeting with the various third parties, understanding their concerns, putting them in the contract, and getting them to the contractor,” Allen says.
Upon completion of the project, the county will have improved connectivity, greater east-west mobility, and improved access to various roads. The bridge will connect two communities that were divided by railroads and canals. Stonebraker adds, “This is something that UDOT and Bluffdale City has considered for a while and this connection will provide additional development opportunities for the city and take pressure and load off of existing infrastructure.”