Big bite of the big apple
May 1, 2007 By: Rodney E. Garrett Pit & QuarryQuarry-style drilling and blasting is used to excavate a large construction site in the Bronx.
The pictures most people conjure up when New York City (NYC) comes to mind are skyscrapers, the bright lights of Broadway, the Statue of Liberty, Rockefeller Center at Christmastime and Fifth Avenue where only the affluent dare to shop.
One of the most extraordinary sights, however, is outside Manhattan in the Bronx, where a great excavation is under way. The excavation opening is nine acres, and will be 90-ft. deep when completed. A total of 175,000 in situ cu. yd. of overburden is being removed, followed by 950,000 in situ cu. yd. (1.6-million tons) of rock.
 Challenge; Solution; Tip |
There are a number of considerations when carrying out a construction project in NYC. There are the logistics to access the project, i.e., construction materials deliveries and the exporting of excavated materials, which are slowed by daily traffic snarls. Additionally, there are strict security regulations to follow during construction activities that were brought about by the tragic 9/11 event. This includes special drilling and blasting regulations.
Sandvik Mining and Construction and its dealer Contractors Supply Inc., has assisted the contractor, Schiavone Construction Company Inc., Secaucus, N.J., in addressing many of the special regulations on drilling and blasting. This includes supplying efficient, environmentally friendly drilling rigs.
Schiavone is making this project a successful one with its skillful management team. The company has many years of experience in carrying out major construction projects in NYC and has continually demonstrated its ability to complete projects on time with quality results.
Only the complete project's cost of $1 billion overshadows the excavation phase of it, which is costing more than $127-million. The owner of the project is the NYC Department of Protection (DEP), which is responsible for NYC's water supply.
 Special regulations on drilling and blasting must be followed during construction projects in New York City. |
A water treatment/filtration plant (designated the Croton Water Treatment Plant Project) will be built on site once the excavation is completed. The plant will be subterranean, lying directly below Van Cortlandt Park's Mosholu Golf Course.
Quarry or construction?
Schiavone decided the most cost-effective method to excavate the rock at this project is the quarry-style drill and blast method, once the overburden is removed using conventional equipment such as excavators, bulldozers and articulated trucks.
There is little difference between this excavation project and a typical stone quarry operation. The drilling and blasting is carried out by making multiple benches with the faces ranging from 10 to 20 ft. high. All blasted rock is hauled to the top of the excavation pit using 70-ton capacity off-road haulers and stacked on the site so front-end wheel loaders can load tri-axle dump trucks. Most excavated overburden and rock is exported to other contractors' construction projects in NYC.
Partnering early on
In considering the extensive rock drilling required for this project, the contractor sought outside expert advice on selecting drilling rig types and production capacities. One of the people consulted prior to making the bid was George Haas, representing Contractor's Sales Co. Inc. of Albany. Contractor Sales is a Sandvik sales and services dealer for specific types of the manufacturer's extensive drilling rig product lines.
 Going an extra mile or two |
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