Coal resources are vital in national energy security, the consumption and production of coal account for 63% and 77% of the primary energy, respectively [1
]. With the long-term high-intensity mining of coal resources, coal resources with simple conditions in eastern China are becoming increasingly scarce. The issue of mining short-distance coal seams is widely distributed in China and has been receiving increasing attention to preserve China’s energy supply. The recoverable reserves of short-distance coal seams account for approximately 43% of China’s total coal resources, and over 65% of the mining areas in China have short-distance coal seams [2
]. The common mining methods for short-distance coal seams are upward and downward mining. Downward mining is the most widely used mining method, i.e., mining from top to bottom [3
]. When the short-distance coal seam undergoes downward mining, the stoping of the upper layer coal causes damage to the floor to a certain depth, and the mining of the lower layer coal is adversely affected by the roof cracking and the abutment pressure caused by the goaf and coal pillars. The law of strata behaviors will be different from the mining of a single coal seam [4
]. Therefore, the analysis of the effects of the goaf resulting from the upper coal seam mining on the law of strata behaviors in the lower coal seam will be of great significance for the safe and efficient production of short-distance coal seams.
At present, scholars have studied and summarized the mining of short-distance coal seams and the mining below the goaf. Based on the damage depth formed in the floor because of mining-induced stress, Yingda defined short-distance coal seam groups and established a structural model control theory for them [5
]. Ming studied the evolution and influence of stress concentration and rock fracture in deep multi-coal seam mining, established a mechanical model using the infinitesimal strain theory, and analyzed the failure of the middle layer at the vertical and horizontal directions [6
]. Cheng et al. studied the control of surrounding rocks during stoping of the protected layers under the protective layers using methods such as similar simulation and numerical simulation; they obtained the relationship between the effects of the support methods on the roadway wall rock and structural evolution and the advancing speed of the working face and the failure height of the wall rock and overburden rock [7
]. Singh et al. determined the stability and support requirements for the short-distance continuous coal seam mining by establishing a numerical model, analyzing and summarizing the prediction formula for the interval between layers [9
]. Qiwei et al. studied the overburden rock structure and crack evolution of the short-distance coal seams and found that the vertical stress concentration moderately decreased on repeated mining, the width and number of cracks gradually increased with the mining of the working face [12
]. Suchowerska studied the evolution law of vertical stress at the ultra-long working face under the conditions of multi-coal seam mining and found a significant correlation between the influence angle of abutment pressure and the vertical stress below the coal pillar [14
]. Shuangsuo used a theoretical calculation method, studied the end face roof via vector analysis, and analyzed the roof structure and mine pressure law during the mining of the lower coal seams [15
]. Mandal et al. established a safe mining system for mining below the continuous coal seam goaf by measuring the impact of mining activities on the upper structure with methods such as field surveys, theoretical analysis, and numerical simulation [16
]. Long and Shimin performed cyclic loading and unloading of coal seams to quantify maximum stress and obtain changes in coal seam properties [19
]. Zhanbo et al. studied the distribution law of non-uniform stress in the floor coal rock mass under the action of residual coal pillars and the reasonable layout of the lower coal seam roadway [20
The aforementioned studies performed detailed analyses of the structure and stability of overburden rock in mining coal seams. However, few studies have investigated the stress distribution law during mining in the goaf. Moreover, the research on the law of strata behaviors during the stoping of short-distance coal seams below the goaf is of great significance for stably supporting the wall rock of the stope. Therefore, this study considers the 051508 fully mechanized working face of the No. 15 coal seam in the fifth mining area of Lingxin Mine as the research object and studies the law of strata behaviors under the influence of the goaf of the upper No. 14 coal seam. The study analyzes the working resistance and distribution of the working face supports support for the 051508 working face when the roof fractured and weighting occurred under the influence of the goaf of the upper No. 14 coal seam and summarizes the law of strata behaviors at the working face, thus providing a reference for the mining of working faces with similar working conditions.