Big boulders are causing big headaches for Virginia’s Chesapeake Bay Bridge-Tunnel expansion project, adding to other issues that have pushed the $756 million effort two years behind its original 2022 completion target.
Weighing as much as 25 tons, the granite boulders armor two 5.25-acre artificial islands where design-build the joint venture of Dragados USA, Inc. and Schiavone Construction Co. LLC are building a 5,700-ft long, 42-ft diameter tunnel to parallel existing tubes at Thimble Shoals Channel, approximately 3.5 miles offshore from Virginia Beach. Quarried during construction of the original 20-mile bridge-tunnel system in the 1960s, the boulders are being excavated as part of the construction of a launch pit for a tunnel boring machine (TBM), which is scheduled to arrive from Germany later this year.