## 6 Conclusions  
In this paper, through numerical simulation, theoretical analysis, and other research methods, the load reduction mechanism of long-distance borehole blasting was analyzed, and the effect of this method was verified based on field practice. The research conclusions are as follows:  
1. Common blasting pressure relief has the limitations of a small pressure relief range and suitability only for low roof treatment. Long-distance drilling blasting pressure relief is arranged by arranging the high-level drilling field above the coal seam, and the long-distance drilling is arranged in a fan-shaped distribution, which effectively pre-splits the whole overburden rock;
2. Based on existing research, the influence of three factors, i.e., blasting the pre-splitting layer, blasting rock thickness, and blasting rock lithology, on the pressure relief effect of long-distance drilling blasting in practical applications, e.g., a working face, is analyzed, and an orthogonal test was designed. Based on the actual drilling information of the working face, a UDEC numerical model was established to analyze the overburden subsidence, stress change, and rock fracture. Taking Scheme 1 as an example, it was found that after long-distance drilling and blasting, the average value of overburden subsidence increased by 21.2%, the maximum value increased by 15.2%, the average stress value decreased by 22.8%, and the maximum stress value decreased by 34%. The orthogonal test results showed that the weight ratio of the blasting effect was as follows: blasting layer position \(\rightarrow\) blasting rock thickness \(\rightarrow\) blasting rock lithology;  
Figure 14: Changes in the displacement of the roof surface of the entry for long-distance drilling and blasting in construction.  
3. Combined with our analysis of the factor weight ratio, the selection of a blasting horizon should be given priority in the design of a long-distance drilling blasting implementation scheme. Combined with actual drilling information, the roof above the 2412 working face was set as the blasting horizon at about 52-67 m. According to our analysis of measured micro seismic data, long-distance drilling blasting can effectively reduce the frequency of micro seismic energy and events, reduce the spatial activity of the working face, avoid the influence of a high roof on the mining period of a working face from the source, release energy over time, avoid the accumulation of large energy events, and reduce the risk of rock burst.  
Conception and design of experiment, Q.G.; provision of ideas and proposal, A.C.; manuscript writing, W.Z. and Q.G.; use of simulation software, Y.Y.; data and graph processing, C.X. and Q.H.; project administration and funding acquisition, A.C. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the National Natural Science Foundation of China (52274098, U21A20110), National Key Research and Development Program (2022 YFC3004603) and Jiangsu Province International Collaboration Program-Key National Industrial Technology Research and Development Cooperation Projects (BZ2023050).  
Not applicable.  
The data used to support the findings of this study are available from the corresponding author upon request.  
The authors are grateful to the coal mine for providing field data. The authors would also like to thank the peer reviewers and editors for their valuable comments and suggestions.  
The authors declare no conflicts of interest.