Study and measurement of overburden failure height above high intensity fully mechanized mining face in shallow seams

REN Chenfeng; SUN Bin; ZHANG Hongkai; HU Yingjie

doi:10.11799/ce202501013

Abstract：In order to explore the overburden failure height of shallow-buried high intensity fully-mechanized mining face,No.12407 working face of Huangyuchuan Coal Mine,two ground boreholes before and after mining are set up at the appropriate position above the working face.Based on the borehole data,the key strata and failure height of the overburden rock are theoretically analyzed and measured in situ,and the failure height of the overburden rock is determined based on multi-index factors.Through on-site measurement methods such as drilling flushing fluid consumption and underground video imaging,the change process of parameters in the process of before and after mining drilling is monitored,and the multi-index comprehensive evaluation of overburden failure height is carried out.The results show that there are two key strata in the overlying strata of No.12407 working face,and the fine-grained sandstone at 88.7～116.5 m depth is the main key stratum of overlying strata.The development height of the water-conducting fracture zone of the overburden rock in No.12407 working face is about 77 m from the coal seam floor,which is close to the position of the main key stratum of the overburden rock,and the main key stratum has an inhibitory effect on the failure height of the overburden rock.Based on the comprehensive analysis of multiple indexes of overburden failure height,it can be seen that under the superposition of special conditions such as shallow burial depth,high-intensity mining and thick and hard bedrock,the applicability of the empirical formula of'two zones,collapse zone and water-conducting fracture zone'to calculate the height of fracture zone in this working face is general,and the development height of water-conducting fracture zone in No.12407 working face is comprehensively determined to be 77 m based on the measured value.