NuStar Energy L.P. is one of the largest asphalt refiners and marketers in the U.S. and the second largest independent liquids terminal operators in the nation. Its worldwide operations include 82 terminal facilities, 8,417 miles of pipeline, four crude oil storage facilities and two asphalt refineries. NuStar Energy wanted to build a bridge structure over pipelines that would support vehicle traffic and allow for visual inspections of the pipe.
“We wanted to monitor and inspect our internal pipelines without excavating each time, but we needed to be able to move vehicles and equipment across those pipelines” said Mike Moore, Operations Manager for NuStar Energy. “A bridge was exactly what we needed”
The native material roads were originally built over the pipelines to allow access for operations and maintenance. Because the pipelines were in operation, a solution was needed that would have minimal business impact and support vehicle traffic. They needed a sturdy, yet economical structure that could be installed without interrupting flow through the pipelines.
NuStar Energy originally considered a cast-in-place, three sided concrete bridge but decided to go with three Aluminum Box Culverts from Contech because they were open bottom structures that could be easily lifted into place over the existing pipes.
The existing soil was removed and the pipes were blasted and repainted. Once completed, the Aluminum Box Culverts were lifted over the pipes and set down on aggregate footing pads. The culverts also provided ample clearance to allow for future maintenance of the pipelines. The project was an overall success and cost considerably less than the proposed cast-in-place three-sided concrete bridge.
“We are very pleased with the end product” said Moore. “The open bottom aluminum structure allowed us to construct the bridges without once interrupting the flow through the pipelines. Now we can access our operations from either side and visually inspect our pipelines whenever needed. What a great solution”