C+S July 2020 Vol. 6 Issue 7 (web)

Along the south side of downtown Fort Worth, Texas sits Interstate 30, Tower 55 Rail Intersection—one of the nation’s busiest railroad intersections –and a newly revitalized urban, mixed-use neighborhood and medical district called the Near Southside. Originally, Interstate 30 ran elevated over a major east-west cor- ridor on the south end of downtown but in the early 2000s, the highway was relocated further south to a more industrial area which include a highly active east-west railroad corridor. When the new highway was built, it flew over the railroad tracks leaving an underpass to be excavated in the future to connect a perpendicular street, Lamar (on the north) and Hemp- Tunneling to Connect Fort Worth By David Wallace, P.E.

hill (on the south). Since then, the long-held desire of the City of Fort Worth to connect the central business district to the south side of town via an underpass tunnel that provides a safe, multi-modal route to and from downtown, gained momentum. Construction of the four-lane vehicular, pedestrian, and bicycle tunnel – known as the Hemphill Street Connector – was awarded to McCarthy Building Companies’ Southern Region under a Construction Manager at Risk (CMAR) contract – a delivery method not often seen within the transportation sector. Under the CMAR delivery model, the benefits to an owner begin in the design phase. The construction manager’s early involvement improves the design through its insights on constructabil- ity, value engineering, cost estimating, and schedule. Additionally, un- like other delivery methods, CMAR provides the owner with a skilled advocate throughout the project which also procures the subcontractors who then perform the work. Construction Management While long planned, moving the project forward was extremely chal- lenging as there were more than eleven stakeholders to coordinate in- cluding TxDOT, Union Pacific Railroad, Downtown Fort Worth, Inc., Near Southside Inc., I-CARE, and multiple others. Further, the project underwent several iterations of design and bidding, and multiple de- lays during the procurement phase. Under the CMAR contract, Mc- Carthy worked with the City of Fort Worth to align the large group of stakeholders and seek consensus to what was best for the community. McCarthy also assessed all project risks and worked to proactively plan these risks out of the project. The general contractor coordinated self-perform and the subcontractors’ work to achieve the highest daily productivity. The team addressed construction coordination among various subcontractors, evaluated their manpower levels, and ensured they performed their work in accordance to the overall construction schedule. McCarthy also managed the Stormwater Pollution Plan, environmental plans and practices as well as tracked the flow of major materials from initial submittals through fabrication and delivery to coincide with the proper construction sequence.

Construction sequence on the project was vital as it was a multi-phased and complex job with various scopes of work that included a railroad track shift to maintain functionality and other special track work, struc- tural steel bridge construction, deep foundation drilled shafts, water- proofing, earthwork and rock excavation, temporary shoring, rock nail and shotcrete retaining walls, precast panel retaining walls, CIP retain- ing walls, living “greenwall” retaining walls, storm drainage, concrete pavement, tunnel lighting, street lighting, traffic signals, landscaping and irrigation, metal handrails, signage and pavement markings, and public artwork. Building Connection The multi-phased project began with constructing a new rail bridge to support four existing Union Pacific Railroad lines that run through the Tower 55 Rail Intersection at the east limit of the project. With more than 100 trains passing through each day, this is one of the na- tion’s busiest and most congested rail intersections. To construct the railroad bridge, McCarthy shifted four existing railroad tracks north in a shoofly configuration for each of the separate tracks. The bridge was built in four phases - two adjacent to live rail traffic and two in the


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