**6. Conclusions**

(1) The characteristics of strong strata behaviors of AHR were obtained by field observation. The specific manifestations of the strong strata behaviors include a large mining impact range, large roadway deformation, severe anchor cable damage, large inclination angle of roadway hydraulic support, and early warning of hydraulic support resistance in the working face.

(2) Based on various factors, the mechanism of strong strata behaviors in the roadway of the Burtai 4-2 coal seam has been obtained. The thicker and harder the roof strata, the greater the elastic energy accumulated before the roof fractures. The reserved roadway was greatly affected by the repeated mining of the working face when the double roadway was arranged, and the stress superposition was obvious. The coal pillar in the goaf of the overlying 2-2 coal seam promotes stress concentration in the 4-2 coal seam, resulting in more complex regional stress field conditions.

(3) Based on the theoretical analysis, the implementation scope of hydraulic fracturing was determined. Combined with the site situation, the pressure relief control technical scheme of hydraulic fracturing in the 42107 working face is proposed. After adopting a reasonable hydraulic fracturing scheme, the average step distance and load of periodic weighting were significantly reduced, the deformation and failure of the roadway were weakened, and high stress transmission in the working face area was achieved.

**Author Contributions:** All authors contributed to this paper. Conceptualization, C.L. and D.X.; methodology, C.L. and Y.L.; validation, C.L. and T.C.; formal analysis, C.L.; data curation, Y.L.; writing—original draft preparation, T.C.; writing—review and editing, C.L. and D.X.; validation, Y.L. and C.L.; funding acquisition, C.L. All authors have read and agreed to the published version of the manuscript.

**Funding:** This work is supported by the China Postdoctoral Science Foundation (2021M700427) and the Innovation Project of CCTEG Wuhan Engineering Company (ZZYF202319 and ZZYF202321).

**Institutional Review Board Statement:** Not applicable.

**Data Availability Statement:** All data and/or models used in the study appear in the submitted article.

**Conflicts of Interest:** The authors declared no potential conflict of interest with respect to the research, authorship, and publication of this article.

#### **References**


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**Hongyan Lei 1,2, Linchao Dai 1,2,\*, Jie Cao 1,2, Rifu Li 1,2 and Bo Wang 1,2**


**Abstract:** In view of the problems of heavy work, long cycle, high cost and low efficiency in the process of indirect determination of coal seam gas content, the basic gas parameters and coal quality indexes of 24 coal samples from 5 coal mines in the Hancheng area of Shanxi Province are measured by the laboratory measurement method. The raw coal gas content–gas desorption index of drilling cuttings (*W*–*K*1) relationship model is characterized by logarithmic function. Using SPSS data analysis software, a stepwise multiple linear regression method is used for statistical analysis. The results show that the factors that have a significant impact on the regression slope *C* in the *W*–*K*<sup>1</sup> relationship model are gas adsorption constant (*a*), apparent density (*ARD*), initial velocity of gas diffusion (Δ*p*) and consistent coefficient (*f*). The factors that have a significant impact on the regression constant *D* are Δ*p* and atmospheric adsorption (*Q*). Then, the mathematical model of rapid prediction of coal seam gas content is determined. Compared with the measured values, the average absolute error rate is 12.84%, which meets the prediction requirements and provides a simple and easy method for rapid determination of coal seam gas content in coal mines in the Hancheng area.

**Keywords:** coal seam gas content; *W*–*K*<sup>1</sup> relation model; multiple linear regression; gas pressure
