Project strengthens and adds tunnels to subway

Article Abstract:

The New York Metropolitan Transportation Authority (MTA) is already using the two 1,100-ft long subway tunnels running beneath Queens Boulevard in New York City, NY. The tunnels were built at a cost of $160 million and took four years to complete. The construction was so complex that engineers devised a way to alter the existing tunnel's structural system such that the new tunnels could be built in greater safety. Chief engineer Bernard Grand said the tunneling operation was turned into an opencut project so they did not have to work under loaded areas.

Public works, New York, New York

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Cutting off water in Queens

Article Abstract:

The New York City Transit Authority began a project to connect a dead-end subway stop in Queens to other routes in 1992. Contractors used tunneling to allow the uninterrupted operation of the subway while cut-off walls were constructed to minimize the drawdown of the contaminated groundwater outside the excavated areas. However, digging for the installation of cut-off walls was made difficult by the presence of boulders and the density of the soils.

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Tunneling beneath Cairo

Article Abstract:

Issues discussed concern the design and construction of an urban underground rail system in Cairo, Egypt. Topics addressed include the need for the Greater Cairo Metro System to maintain structural integrity in the saturated soil conditions, and the use of computers to control tunnel-boring machines.

Egypt, Statistical Data Included, Transportation, Cairo, Egypt (City)

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