Earth shifting trough

The line that limits the mining influence zone on the surface is the boundary of the displacement trough ; it is defined as the geometric location of points on the surface with a subsidence of 10 mm or at boundary angles. The part of the displacement trough, in which the surface points have the greatest subsidence, is called the bottom of the displacement trough.

Within the displacement trough, a zone of dangerous displacement is identified, where displacements and deformations are dangerous for undermining structures, and a zone of cracks defined relative to the boundaries of mining operations, respectively, by the angles of displacement and the angles of rupture. When developing steeply dipping formations in the troughs of displacement, dips can form.

There are troughs of displacement with a flat and concave bottom. In the first case, due to the large size of the mine working compared to the depth of development, a part of the surface (full moonlighting ) within the trough of shear undergoes extreme shear and it is fully developed. In the absence of a flat bottom in one of the main sections of the Muldy of displacement, an incomplete underworking of the surface takes place.

The position of the point of maximum subsidence in the displacement trough with a concave bottom is determined using the angle of maximum vertical displacements.

The extreme points of the flat bottom of the displacement trough on vertical sections are determined using the angles of complete displacements. In the trough of displacement, zones of dangerous and safe displacements are distinguished. The boundaries of the zone of dangerous surface displacements or critical deformation points are determined using the displacement angles.

• Mulda (geology)

• Mulda of displacement Mountain Encyclopedia