PROJECT The East Span of the San Francisco Oakland Bay Bridge had been replaced, leaving a line of concrete piers nearly 2 miles long in one of the world’s busiest harbors. Removing them was the final stage in the 4-year, high profile bridge seismic safety replacement project.
SOLUTION The initial attempt to demolish the piers by hammering was rejected due to the detrimental effects on water quality and the bay fishery. Hammering is messy; air quality monitors don’t like it due to dust and noise, effluents are hard to contain therefore water quality regulators don’t like it, and fish biologists don’t like it for all those reasons. It was determined that cutting the “pillar” portion of the piers above water into blocks sized for removal would be a cleaner and more efficient method.
Kiewit/Manson AJV was operating within a 4-month window to remove the above-water portion of the piers, each weighing approximately 320 tons, before the seasonal migration when most fish departed the harbor and the remaining underwater portion could be exploded. Bluegrass mobilized men and equipment to Oakland.
CHALLENGES The job required skill and efficiency, but was not particularly complex. Slurry control was critical, and we are experienced meeting such requirements. Our men and equipment operated steadily, cutting pier after pier into 4 blocks weighing approximately 80 tons each. The first 4 piers were completed in half the anticipated time, and the contract was extended to cut and core drill 4 more. Those 4 were cut and drilled for rigging, and the contract was extended again. In all we wire sawed 10 piers and core drilled 9.
OUTCOME With men and equipment operating at peak performance, we finished cutting the last of 10 piers in the time initially allocated for cutting 4, advancing the removal project a year ahead of schedule. We accomplished this with a perfect safety record and no environmental violations. Bluegrass was awarded Best Partner by Kiewit/Manson AJV. Nominated by Caltrans, Bluegrass was the first subcontractor to receive this quarterly award.
This Phase 2 SFOBB project received the prestigious Excellence in Partnering award from the AGC of California, in October 2018, and at the World Demolition Summit it received the "Best of the Best" award and first place in the Collaboration Category.
Your early success was instrumental in allowing our project the opportunity to complete, two seasons worth of inwater work in one season, affording us, Kiewit Manson AJV, the ability to beat our CPM schedule by a full year. -- Zach Reilly, Project Manager Kiewit / Manson AJV
To deliver a project 12 months early and generate a saving of US$20 million dollars is truly a world class project and a testament to the foresight and collaborative approach involved. --International judging panel, World Demolition Summit 2018