subgrade

American  

[suhb-greyd] / ˈsʌbˌgreɪd /

noun

1. the prepared earth surface on which a pavement or the ballast of a railroad track is placed or upon which the foundation of a structure is built.

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adjective

1. beneath the finished ground level of a project.

subgrade British  

/ ˈsʌbˌɡreɪd /

noun

1. the ground beneath a roadway or pavement

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Etymology

Origin of subgrade

First recorded in 1895–1900; sub- + grade

Example Sentences

“Reinforcing the ground below the tracks required removing any work already completed, excavating additional soil beneath 1400 feet of track, and installing new subgrade materials to provide the required stability,” according to WMATA.

From Washington Times

They say the assessment indicated that the south end of the runway has deteriorated significantly, large cracks exist, precipitation is leaking through the cracks into the subgrade and the existing pavement is raveling.

From Washington Times

One reason for the extensive trailer rig, says Zander, “Highway 14 does not have the best subgrade. Because of this we had to work closely with the state and our engineering department to come up with a configuration that would not damage the road.”

From Seattle Times

The intent is not to go back to the Legislature repeatedly for approval of smaller, more incidental permits, such as a change in subgrade to a road, Gustafson said.

From Seattle Times

It is estimated the cost will be $109,000.00 to complete the subgrade, and it is expected this project will be commenced in 1919.

From Project Gutenberg