Maggiora & Ghilotti, Inc.
Bunker & Mitchell Roads and Alexander Avenue
What makes it interesting?
The project was located in one of the most beautiful parks in the country, overlooking the Golden Gate Bridge in San Francisco, California. The project included the National Park Service, FHWA, the City of Sausalito, and the entire San Francisco Bay area and very tight deadlines were involved to have the site ready for San Francisco’s first America’s Cup. It is the largest contract that Maggiora & Ghilotti has been awarded.
How HCSS Software assisted with this project
The project was located in one of the most beautiful parks in the country, overlooking the Golden Gate Bridge in San Francisco, California. The project included the National Park Service, FHWA, the City of Sausalito, and the entire San Francisco Bay area and very tight deadlines were involved to have the site ready for San Francisco’s first America’s Cup. It is the largest contract that Maggiora & Ghilotti has been awarded.
Project Description:
The Bunker and Mitchell Roads and Alexander Avenue project was on a tight deadline, as the widening of Alexander Avenue just north of the Golden Gate Bridge needed to be completed prior to the July 4 start of the America’s Cup. Because earth could not be disturbed prior to April 1, the widening and improvements would need to be completed in three months. It was a large task involving excavation and construction over a historic tunnel and cutting a the slope between the tunnel and a busy off-ramp.
The tunnel was to be preserved by utilizing smaller equipment to excavate above the tunnel allowing for the construction of eight micropiles 70 feet deep to support the installation of a 3-foot-thick concrete slab over the tunnel. A Mechanically Stabilized Earth wall was then constructed above the slab to allow for widening above the tunnel.
In order to maintain the schedule, the 17,000-cubic-yard cut slope needed to be completed during the work above the tunnel. The cut came to a stop after Maggiora & Ghilotti got through the beautiful native red chert material and hit rock so hard that the excavator couldn’t scratch it. They had to bring in the big guns, a D10 Dozer, to rip the rock. However, the cut was not wide enough to accommodate the full width of the D10, so the blade had to come off, which just barely provided enough room (and sometimes not enough as a partial track hung out over the slope at times.) M&G got back on schedule and finished the work on time and on budget.
Within the Park, the project involved upgrading of the facilities servicing the park, including a main roadway; new parking lots; restoration of a wetland; new chert parking areas and walkways (the chert being manufactured from the cut on Alexander Ave.); restoring a hillside known as Fort Cronkhite Annex Parade Ground Quarry, which was excavated during WWII (top portion of the hilltop was not rebuilt to memorialize the existence of the historical quarry.); and retaining walls, valued engineered during the project (HCSS was used to value engineering and present proposals to the FHWA).
The project was bid in December 2012 using HCSS Heavy Bid. The FHWA awarded Maggiora & Ghilotti the project in January 2013. The overall project value of $11,257,000 was and still is the largest contract the company has been awarded.
