Development Characteristics And Water Inrush Evaluation Of Floor Failure Zone In Working Face Under 24m Mining Height

In the process of mining,water inrush is often caused by floor failure of working face.Therefore,the reasearch of the development characteristics of the floor failure zone in the working face is of good significance to the water inrush from the floor.In the current research on the failure mechanism of the coal seam floor,the development law of the coal seam floor failure is not clear.In this paper,the 61601 working face of longwanggou coal mine is taken as an example,and field measurement is carried out by the floor network parallel electrical method.Combined with FLAC3 D,the failure numerical simulation of coal seam floor in working face is carried out.Through comprehensive analysis of the two methods,the failure depth of working face floor is 15 m,the depth of floor disturbance zone is 25 m,and the depth of leading disturbance zone is 20 m.By setting up a monitoring line in the numerical simulation to monitor the vertical stress,shear stress and horizontal stress,and combining with the measured resistivity in the borehole,the quantitative relationship between the resistivity and the three stress data was comprehensively analyzed.The peak position and influence range of the vertical stress are obtained,which will increase with the increase of the mining height,and the shear stress is the main factor affecting the failure depth of the bottom plate of the working face.Through empirical formula and theoretical analysis,it is concluded that when the mining height of working face is large enough,the failure depth of working face bottom plate will decrease.On this basis,the "lower three zones" method,the theoretical formula calculation method and the stress distribution law of the floor are used to evaluate the floor water inrush of the working surface.The dynamic change of water inrush from floor of working face is obtained.By "five figure coefficient method" of mine water bursting evaluation,by means of the western and central three suspected of collapse anomaly area belongs to the danger zone,western mining field in the danger zone main reason is because it is a high pressure area,in the process of production in the future need of western mining area Shu Fang step-down and collapse column probe into three abnormal area.There are 61 figures,21 tables and 99 references in this paper.