Thursday test at Dulles Metrorail project may sound like small explosion

By Ashley Halsey III
Washington Post Staff Writer
Wednesday, January 6, 2010; 4:21 PM

A sound that may be mistaken for a small explosion will be heard Thursday in McLean as contractors building the Dulles Corridor Metrorail Project test the structural integrity of a caisson near the interchange between Dolley Madison Boulevard and the Dulles Connector Road.

The test is scheduled for about 1 p.m. if weather permits.

It is a routine test to gather data about the load capacity of caissons, which are the underground portions of the piers that will support the aerial structures of the future Metrorail tracks.

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