Abstract:
Taking return airway of No.2209 working face of Cuijiagou Coal Mine as engineering background, deformation of roadway surface and deep surrounding rock of roof were monitored for 30 d by use of cross distribution point method and roof separation indicator. The results show that cumulative convergence between roof and floor is 142—222 mm, cumulative convergence between two side walls is 140—294 mm, cumulative floor heave value is 54—94 mm, and cumulative roof separation value is 44—77 mm. The convergence between roof and floor, convergence between two side walls, floor heave value and roof separation value are increasing; floor heave is more obvious in which deformation of roof and two side walls are large. Roof separation occurs in range of deep and shallow basis points. In the early stage of monitoring, deformation of roof and floor and two side walls is in slow convergence phase. In the late stage of monitoring, deformation of roof and floor and two side walls is in accelerated convergence phase, which indicate that roadway has entered the secondary deformation stage.