By rosebell
With the aim of advancing the BART Silicon Valley Phase II (BSVII) project, a 66m crane, one of only four in the US, and the only one currently operating on the West Coast, has been deployed for this project.
Considering that the project enters a critical construction phase with the installation of steel rebar cages deep into drilled shafts, this crane is stationed at the West Portal and TBM launch site.
In order to lifting rebar cages, the crane is due to use a custom-built tripping frame and some of them are over 43m long and weigh over than 13.8 tonnes, and lower them into vertical shafts. Due to providing the safe and controlled movement of the steel structures, the tripping frame is essential to this process, and that would otherwise be impossible to handle.
While the required time for each installation is around 26 hours, once in place, the cages are filled with concrete to form the reinforced columns that will support underground walls and infrastructure, necessary to launch the TBM.
Thirty-nine semi-trucks were required to deliver the crane to site.
According to BSVII director of construction Sarah Wilson: “This is a rare machine and seeing it in action is like witnessing the muscle behind modern infrastructure. Its presence signals one of the most exciting and transformative stages of the project: vertical construction.”
The Santa Clara Valley Transportation Authority (VTA) said:”The use of such rare, specialised equipment underscored the project’s scale and complexity.With only four cranes of this size and type in the country, and just this one operating on the West Coast, its deployment highlights the national significance of this infrastructure project.”
Linking Berryessa/North San José Station through downtown San Jose to the City of Santa Clara, the BSVII extension is a 10km, four-station addition to BART.
