A multifactor coupling prediction model for the failure depth of floor rocks in fully mechanized caving mining: a numerical and in situ study

To study the mining-induced failure depth of floor rocks in a fully-mechanized mining caving field affected by different coal seam pitches, mining face lengths, burial depths and aquifer water pressures, multifactor coupled orthogonal numerical tests on the failure depth of floor rocks were conducted. The numerical results show that the failure depth of floor rocks increases with increasing mining face length, coal seam pitch and burial depth. According to the relationship between failure depth and these impact factors, a multifactor coupled prediction model for the failure depth of floor rocks was established. In addition, the in-situ measurement of the failure depth of floor rocks in the Yitang Coal Mine in Huoxi coal field in Shanxi Province, China, was performed, and the in-situ failure depths of floor rocks in the 100502 (80 m) and 100502 (180 m) mining faces were approximately 12.50~14.65 m and 17.50~19.20 m, in good agreement with the results of the multifactor prediction model. ...