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The influence of pauses in longwall working on surface strains as measured by soil'strain measuremen |
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The influence of pauses in longwall working on surface strains as measured by soil'strain measurement devices Authors: J. Gustkiewicz, A. Kanciruk, L. Stanisławski
Observations have been conducted of horizontal soil strains resulting from longwan working as monitored by lines of strain transducers. The observation lines were installed in the area where the underground extraction took place parallel to their laid direction. Measurements were taken every three hours. In one case the observation period exceeded one year; in the other took place over a period of over 8 months. With a face advance of about 8 m per working day, an evident influence of weekend breaks in working on regular accelcrations and retardations of strains in time could be observed. However, the phenomenon was not observed when the face advance was only 4 m per day. Hence, there must be a critical face advance rate above which the influence of rhythmic stoppages in working is manifested on the surface.
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2011