Galveston Causeway Vertical Lift Railroad Bridge

This joint venture project consisted of erecting the new Galveston Causeway Railroad Bridge and constructing an 800-foot-long tunnel under Galveston Bay to carry new water lines. The bridge is a 382-foot main lift span that rises 80 feet to allow Intercoastal waterway traffic on Galveston Bay to pass under the BNSF Railroad. All bridge work, including electrical, was self-performed by joint venture forces.

Challenges of this project included the placement of all of the mass concrete for the tower foundations. Each pier has approximately 5,000 cubic yards of concrete that were placed in varying lifts, ranging from 700 to 1,300 cubic yards. Several constraints on the placement of the mass concrete included the maximum time allowed from batching to placement, the concrete slump and placement temperature requirements, the prohibition of driving concrete trucks onto the causeway bridge due to excessive loading of the roadway structure, and the concern about maintaining a steady placement rate to prevent cold joints or early set-up of the concrete.

To place the concrete, our team used a slick line on material barges, with a trailer pump, and a pump truck with a placing boom. A third truck pumped concrete from the I-45 highway bridge into the trailer pump below, where it was propelled though the system and placed with the boom. This method was not solely weather dependent, and the flexibility of the boom truck allowed for adjustment to active rail traffic.

Perhaps the biggest challenge was the float-out of the old bascule bridge and float-in of the main span. This float-out/float-in procedure had to be completed within a 72-hour marine channel shutdown, with only a 12-hour window to close the bridge from rail traffic. The main span was built at the port, placed on barges, and then floated into place, with only eight inches of clearance between the towers and new span.