IH-820 Northbound Lanes Team Completes Delicate Bridge Demo

Technically challenging operation required close communication with stakeholders. 

Flatiron is now several months into the IH-820 Northbound Lanes project traffic over the Trinity Railway Express Railroad in North Richland Hills, Texas.  

The project has numerous parts. A new roadway (supported by mechanically stabilized earth walls) will connect to a future bridge, part of a Texas Department of Transportation expansion plan.  A permanent stormwater drainage system will be installed to collect and redirect stormwater from the bridge and roadway southward, into the existing double-barrel culvert just north of key thoroughfare, Trinity Blvd. The project will re-establish approximately 12.72 acres that will involve removal of existing bridge section, construction of mechanically stabilized earthen retaining walls, new asphalt & concrete pavement and proposed TRE overpass IH 820 Northbound Mainlane bridge. 

Recently, our team achieved a key milestone by demolishing the existing IH-820 Northbound Mainlane Bridge over TRE train tracks to make way for the future bridge.  

The bridge demolition was scheduled during train blackouts, coordinated with TRE representatives, and carried out within TxDOT specifications. Flatiron participated in a pre-activity meeting with the stakeholders involved to make sure everything proceeded smoothly. 

The demolition occurred in three distinct sequences: bridge spans 3-5 (Sequence 1), span 2 (Sequence 2), and span 1 (Sequence 3). Columns and caps within each section were demolished concurrently. Sequences 1 and 3 were demolished in place, while Sequence 2 required a crane to protect the railroad tracks. Track shield protection, comprising plywood sections built from 2×8 lumber, was installed to safeguard the tracks from falling debris. A 600-ton crane with a counterweight of 297,000 pounds was used to lift and place each section in the designated beam area. Rubble was broken down, separating concrete and rebar, and hauled to a third-party crusher for recycling into flex base for other construction projects. 

Flatiron’s successful bridge demolition demonstrates the team’s diligence in addressing safety, environmental considerations, detailed assessments and regulatory compliance. This highlights Flatiron’s strength and expertise in delivering crucial projects in tightly knit work zones, providing safer and higher-quality products to our valued customers. The integration of all key steps from planning to execution was the main reason for the operational efficiency demonstrated in the bridge demolition. 

Following the demolition of the existing bridge, mass excavation will happen on both sides. Construction of retaining walls will commence along the rock embankments, as well as substructure work, including drilling shafts, columns and caps for the proposed IH 820 North Bound Main Lane bridge. The project is contractually set for 18 months, with our teams collaborating with TxDOT to ensure substantial completion and handover by late 2025. This timeline reflects Flatiron’s commitment to delivering high-quality projects in a timely manner.