# Risk Identification Method and Application of Roof Water Inrush Under Multi-Working Face Mining
## 7 Conclusions  
* A method of risk identification for roof water innyush under multi-working face mining conditions, based on the theory of Key Strata and Full Mining Disturbance, has been proposed. This method comprehensively accounts for the effects of repeated disturbances from multiple working faces and involves the derivation of a critical dimension formula for the key strata at the working face. When the critical dimension of the working face of the key stratum exceeds the combined width of the two working faces, the maximum development height of the water-conducting fracture zone is determined to be equal to the height of the key stratum. In contrast, if this dimension is less than the combined width, the maximum development height of the water-conducting fracture zone corresponds to the height of the unfractured portion of the upper key stratum. Furthermore, if the critical dimension exceeds the width of the preceding working face but remains less than the combined width of the working faces, there exists a risk of delayed water innyush from the roof of the preceding working face. Additionally, when the main key stratum experiences fracturing, the maximum development height of the water-conducting fracture zone is either equal to or greater than the thickness of the bedrock.
* Based on the theory of Key Strata and Full Mining Disturbance, in conjunction with numerical simulation calculations, it was determined that, for a mining height of 4 m, the development height of the water-conducting fracture zone in the 120501 working face is approximately 60 m, with the protective strata thickness ranging from 100 to 140 m. Under these conditions, there is no risk of roof water innyush, and the adjacent 110504 working face is not at risk for delayed roof water innyush.  
* Microseismic monitoring was employed to measure the development height of the water-conducting fracture zone in the 120501 working face, which reached a maximum of 64 m. The development height of the water-conducting fracture zone in the 110504 working face remained unchanged, and no delayed roof water intrush was observed. The results align closely with the theoretical predictions, further validating the proposed method.  
Conceptualization, Z.H.; investigation, B.F. and Y.Z. ([PERSON]); methodology, Z.H.; software, Y.Z. ([PERSON]) and X.L. ([PERSON]); supervision, K.W. and X.L. ([PERSON]); writing--original draft, Z.H.; writing--review and editing, K.W. and X.L. ([PERSON]). All authors have read and agreed to the published version of the manuscript.  
The research described in this paper was financially supported by the National Natural Science Foundation of China (No. 52204172, 52174122, and 52374218), the Excellent Youth Fund of Shandong Natural Science Foundation (No. ZR2022 YQ49), and the Taishan Scholar Project in Shandong Province (No. tsqn202211150).  
Not applicable.  
The data used to support the findings of this study are available from the first author upon request.  
The author would like to thank reviewers and editors for their kind work.  
The authors declare no conflicts of interest.