Abstract: For the inefficiency of the loose rock theory and numerical simulation in the study of loosened surrounding rock scope in the rectangular roadway, based on the data obtained from on-site measurement of loosened surrounding rock scope in the main roadways of Wangcun mine, Wangxie mine, Erkuang mine as well as Dongjiahe mine by means of multipoint displacement and drilling peeping, this paper established different prediction formulas of the loosened surrounding rock scope with roadway depth, section size, surrounding rock strength as well as various factors under different lithologies. The results show: 1) when the section size of the rectangular roadway is constant, the average thickness of loosening in the roof has a positive growth with the roadway depth and anti-growth with compressive strength of the roof; 2) when the depth of the rectangular roadway is constant, the average thickness of loosening in the roof has a positive growth with span-height ratio of the roadway and anti-growth with tension and compression strength ratio of the roof rock; 3) when the lithology of the sides is constant, the average thickness of the loosening in the sides rock of the rectangular roadway has a positive growth with the depth and proportional positive growth with the span of the roadway. Field supporting test of the transport trough was conducted in the 13503 coal face in Wangcun mine according to the obtained prediction formula, which achieved good effect in controlling the surrounding rock.

Key words: rectangular roadway, the broken zone, field test, stable control of the surrounding rock