TYLin provided the engineering design for the dismantling and demolition of the Gerald Desmond Bridge in Long Beach, California.
Constructed in 1968 and seismically upgraded in 1995, this through truss arch structure featured a 410-foot main span and a vertical clearance of 155 feet. The 5,234-foot-long bridge carried four lanes of Ocean Boulevard across the Cerritos Channel to Terminal Island. Its replacement, the Long Beach International Gateway Bridge, is a higher structure on an adjacent alignment that allows larger modern container ships to access the inner harbor.
TYLin investigated several feasible techniques for the demolition. The team recommended a baseline set of methods that offered the best value to the Port of Long Beach. These included recommendations for removal of the suspended span, cantilever arms, anchor arms, channel crossing and approach decks, as well as girders, piers, and abutments.
Lowering the suspended span was the most complex operation of the deconstruction, and accomplished by transferring the 3,200-ton load to four strand jacks installed on top of the cantilever arms. The 410-foot-long suspended span was then disconnected from the cantilever arms by torch cutting the supporting truss members and lowered by the jacks to the barge — a procedure that took eight hours to complete.
The barge was immediately moved to a nearby pier, and the suspended span was dismantled from the barge. The cantilever arms and anchor spans were deconstructed by removing the concrete deck and lowering large segments of the steel truss framing to the ground with cranes for further dismantling.
- TYLin provided civil and structural design, development of contract documents, and design support during the bridge deconstruction.
- Our performance-based plans and specifications allowed bidding contractors the flexibility to innovate and develop techniques that suited their capabilities while maintaining safety.
- All steel and concrete elements from the demolished bridge were recycled.