|
|
Screening
banks
Screening banks (also known as amenity banks) are often used
to limit the views into the quarry operations. They also have
other functions, including acting as 'baffles' or barriers
to reduce noise or dust, which would otherwise reach unacceptable
levels beyond the site.
As with any artificial slope, whether excavated or constructed
from loose materials, the primary concern is stability. Screening
banks are engineered structures that have to be designed in
accordance with the Quarries Regulations 1999. All banks are
subject to hazard appraisals and, where necessary, to geotechnical
assessments, because the collapse of a screening bank can have
serious consequences for anyone who happened to be nearby.
An assessment of the stability of a screening bank will include
consideration of:
- The nature and strength of the materials used to form
the bank
- The condition of the ground on which the bank is built
- The height and slope angle of the bank
- The flow of water
Very large screening banks can be constructed of excavated
rock covered in overburden materials and planted to create
a landscape feature. However banks built of topsoil should
not normally exceed three metres in height, whereas those of
subsoil can reach, but should not exceed, five metres.
|
Newly established screening bank at a sand
and gravel quarry in West Yorkshire.
Consideration has to be given to the type of vegetation to
be planted on the screening bank. Topsoil banks can be worn
away by the wind unless grass is seeded onto their slopes.
However, trees and shrubs are not generally planted if the
screening bank is only temporary in nature. |
