The phrase "below the ground level" is correct and usable in written English.
"Below the ground level" can be used to describe a physical location that is a certain distance below the ground. For example, "The tunnel entrance was located below the ground level."
Lateral pile deflection, 8 to 10 diameters below the ground level, is negligible in most cases.
The ground water level was about 2 m below the ground level at the location of the pit.
The Environment Agency estimates that in the last century, the water table sank to 93 metres below the ground level of Trafalgar Square.
An image detection chamber has been set inside a concrete block below the ground level without changing the frame structure for anti-vibration.
As a result the availability of ground water in these areas dropped down to 135 m below the ground level in northern part of the city and 145m in stretch southern part of the city.
In Latin, crypta designated any vaulted building partially or entirely below the ground level, such as sewers, the stalls for horses and chariots in a circus, farm storage cellars, or a long gallery known as a cryptoporticus, like that on the Palatine Hill in Rome.
Turned out that the ground level (below which the tanks will sit) was a hill that they plan to build.
The original proposal for a below-the-ground road was changed to ground level.
Looking at his pictures, I was reminded of a recent visit to the Olympic site in east London where in one part of the cavernous excavation a perfectly preserved 18th-century street, with its gutterings and cobbles and pavement, had been revealed, 30ft below the current ground level (after the Blitz, apparently, the rubble of bombed houses was dumped above it, layer on layer).
Therefore, the cornerstone was laid below the 1848 ground level.
In 2006, excavations revealed that it continues for some distance below the current ground level.
