## 5 Conclusions  
In recent years, gas outburst accidents in structurally complex areas have become increasingly frequent. This study analyzes the geological characteristics of the present-day Kaiping syncline hinge zone, current gas content, and the generation and occurrence characteristics of gas to explore the controlling effects of regional and local structural patterns on coal seam gas occurrence. The main results are summarized as follows:  
1. The structural distribution of the Kaiping syncline hinge zone shows pronounced north-south differentiation. The strata on the northwestern limb are steeply inclined, with locally vertical or overturned sections, and dip angles generally ranging from 60\({}^{\circ}\) to 85\({}^{\circ}\). Conversely, the strata on the southeastern limb are relatively gentle, with dip angles ranging from 10\({}^{\circ}\) to 30\({}^{\circ}\), further complicated by a series of subordinate folds trending in the same direction. Based on the geological data of the syncline hinge zone, the degree of structural development, and the dip angles of the strata, the area can be roughly categorized into six structural zones: west wing fault structure area, wellhead open syncline area, Kaiping syncline structural zone, monoclonal tectonic zone, Dujunzhuang Anticline structure area, and Heiyazi Syncline structure area. Additionally, the variation in the dip angles of the strata shows a strong correlation with the development of faults and folds within the study area. 2. The Kaiping syncline hinge zone is classified into Structural Zone I (Zhaogezhuang Mine) and Structural Zone II (Linxi Mine) based on variations in coal thickness, strata dip angles, and hydrogeological conditions. The study reveals that in Structural Zone I, the gas content ranges from 4.8 to 12.0 m\({}^{3}\)/t, the relative gas emission ranges from 5.68 to 12.63 m\({}^{3}\)/t, and the absolute gas emission ranges from 19.19 to 35.1 m\({}^{3}\)/min. In Structural Zone II, the gas content ranges from 2.8 to 6.6 m\({}^{3}\)/t, the relative gas emission ranges from 3.74 to 6.87 m\({}^{3}\)/t, and the absolute gas emission ranges from 9.27 to 14.86 m\({}^{3}\)/min. Overall, both gas content and gas emissions show a significant increase with coal seam depth. Gas content and gas emissions on the northern limb of the hinge zone are notably higher than those in the southern structural zone, suggesting that structural complexity plays a significant role in influencing gas distribution and emission. 3. The coal-bearing strata in the Kailuan mining area have undergone structural burial, thermal evolution, and hydrocarbon generation, with subsequent preservation conditions ultimately determining the characteristics of gas occurrence in the coal. The burial history of the coal seams on both limbs of the Kaiping syncline is approximately \"V-shaped\", with a turning point in the Late Indosinian period. The coal seams in the study area have undergone multiple cycles of subsidence, hydrocarbon generation, and dissipation, resulting in varied current states of gas occurrence. Through quantitative analysis of the evolution of the \"three histories\" and coal seam characteristics, the complete process of gas generation, occurrence, and migration in the study area has been revealed. This process is divided into five stages: the initial generation stage, the deep burial and enrichment stage, the stagnation and dissipation stage, the intense accumulation and reservoir formation stage, and the dissipation and stabilization stage. 4. Gas occurrence in the study area is stepwise, controlled by geological structures. North China Craton governs regional gas generation, migration, and preservation, while the Kaiping syncline plays a dominant role in controlling gas occurrence in the Kailuan mining area. The structural differences and burial depths on the two limbs of the turning end are the main factors influencing the variation in gas occurrence between the two limbs. Conceptualization, Z.C. and Y.Z. ; methodology, Z.C. ; software, Z.C. and Y.Z. ; validation, Z.C.