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Soft-ground etching uses a special softer ground. The artist places a piece of paper (or cloth etc. in modern uses) over the ground and draws on it. The print resembles a drawing. Soft ground can also be used to capture the texture or pattern of fabrics or furs pressed into the soft surface.
A ground is waxy material applied to the surface of a metal etching plate. A metal etching plate is a piece of sheet metal, usually copper, zinc, steel, or aluminium.The ground resists the acid or mordant which is used for etching, protecting areas of the metal plate.
Underground soft-rock mining is a group of underground mining techniques used to extract coal, oil shale, potash, and other minerals or geological materials from sedimentary ("soft") rocks. [1] Because deposits in sedimentary rocks are commonly layered and relatively less hard , the mining methods used differ from those used to mine deposits in ...
Soapstone is relatively soft because of its high talc content—talc has a definitional value of 1 on the Mohs hardness scale. Softer grades may feel similar to soap when touched, hence the name. No fixed hardness is given for soapstone because the amount of talc it contains varies widely, from as little as 30% for architectural grades such as ...
Tunnel Construction. Tunnels are dug in types of materials varying from soft clay to hard rock. The method of tunnel construction depends on such factors as the ground conditions, the ground water conditions, the length and diameter of the tunnel drive, the depth of the tunnel, the logistics of supporting the tunnel excavation, the final use and shape of the tunnel and appropriate risk management.
Soft ground drilling can be undertaken using a rotary auger or wash boring techniques, while rock drilling often use methods such as NMLC which allow for recovery of a core of material which can be examined to determine the strength, degree of weathering, understanding of any how intact the rock is and identify any discontinuities or other ...
Chalk is a soft, white, porous, sedimentary carbonate rock.It is a form of limestone composed of the mineral calcite and originally formed deep under the sea by the compression of microscopic plankton that had settled to the sea floor.
The material is increasingly being used at domestic properties as a low cost and environmentally friendly alternative to concrete and block paving in paths and driveways. [1] A compacted sub-base of larger crushed stone is often laid prior to the top layer of hoggin, especially if the area to be covered is soft ground, or prone to puddling. The ...