OAKLAND - At a meeting tomorrow of the Toll Bridge Program Oversight Committee (TBPOC), Caltrans engineers will outline plans for the next phase in demolition to the Old Bay Bridge. Starting early 2016, entire pier-to-pier sections of the old bridge - more than 500 feet long - will be lowered onto barges that will ferry them to shore for dismantling. At the same meeting, officials will update the panel on the water-quality and wildlife effects of last month's Pier E3 implosion and discuss progress in protecting the tower's anchor rods.
Dismantling of the old Bay Bridge seemed gradual since traffic was shifted to the new bridge on Labor Day 2013. That changed with the implosion of Pier E3, the largest of the underwater concrete piers supporting the Depression-era structure. Many in the Bay Area watched in person, online or on television ashundreds of small charges collapsed the concrete-and-steel structure into its own foundation on November 14.
The next phase of the historic dismantling project will unfold as soon as late January or early February whencrews will cut the first of five 1,950-ton sections of the old structure free of its piers and lower it 180 feet to barges below.The exact date for the event will depend on weather conditions.
"Lowering these spans will represent the largest sections that will come down during the demolition of the eastern spans. The actual lowering will take roughly eight hours and is very dependent on wind, rain and wave actions."
During Thursday's meeting, lead Bay Bridge engineer Brian Maroney will give oversight committee members an update on the environmental effects of the implosion. Preliminary reports suggest the blast had a smaller than expected effect on water quality, and caused less disruption to fish life than had been anticipated, proving it to be an environmentally sound method to remove the pier. Maroney also is expected to lay out options for further use of the implosion method for removal of many of the remaining piers.
"The demonstration project (Pier E3) proved that the implosion demolition has the least environmental impact and is the most cost effective."
Maroney also will brief committee members on the continuing efforts to protect rods in the tower foundation. Recent tests pulled on those rods with earthquake level forces, results showed the rods are performing as expected. However, the oversight committee directed Caltrans and a team of experts to continue analyzing the situation and determine the best way to protect the steel for the next century and a half.
On Thursday, engineers will discuss the progress of their investigation, as well as discuss the benefits and drawbacks of cathodic protection, a method of corrosion protection sometimes employed on certain pieces of infrastructure.
The hearing is scheduled from 9 a.m. to 11 a.m. at 171 Burma Road, Trailer 1, in Oakland. The hearing is accessible by phone at 1 (866) 803-2146, access code 2474385.