Mechanized longwall mining is considered as one of the best choices for excavating low dip coal seams. In this method, the position and movement of power supports play an important role in production, safety and performance. In this article we surveyed stress condition around the longwall face based on a numerical simulation using FLAC3D software. Then the effect of stress distribution and geomechanical condition of roof and floor strata in longwall face on power supports function has been studied too. As a case study we chose First panel of mechanized Tabas coal mine in Iran. The approach that has been used in this paper could be considered as a new systematic observational method, especially for second panel of Tabas coal mine.
Parvadeh coal mine is located 85 km off the south of Tabas city inYazd province in mid east of Iran. Because it is located on a desert line it has a dry weather, sparsely having trees.
Tabas coal mine has probable amount of ore about 357 million tons, and its proved reserve is around 270 million tons for B1, B2, and C1 strata in Parvadeh carbonaceous zone (Moeen 1993). B1, B2, and C1 strata have more than 80 cm thickness in vast zones of east Parvadeh and among them C1 seam, which is the main layer in this paper, has an equal extension all around the Parvade zone. C1 seam is the thickest stratum in west part of the zone with the average thickness of 1.83 cm. Also its extension in the length of the outcrop is around 40 km and follows the seam dip toward the Ghourichaai fault (30 km off the out-crop).