地表裂缝是陕北煤矿区最常见的一种地质灾害，不仅损伤地表生态环境，与覆岩裂隙贯通的地表裂缝还是地表水溃入井下的主要通道，威胁井下安全生产。

为进一步揭示浅埋煤层开采地表裂缝发育规律，并阐明其形成及演化机理，以陕北红柳林煤矿15218工作面和25213工作面为研究对象，采用地表裂缝填图、裂缝动态监测和数值模拟等方法，对地表裂缝进行深入研究。

研究表明：(1)浅埋煤层开采地表裂缝整体呈“C”形展布，其发育特征与发育位置和地貌类型密切相关。相同开采条件下黄土沟壑区>5 cm宽度的裂缝数量占比是风沙滩地区的2.15倍，发育程度明显大于风沙滩地区；工作面边界裂缝发育程度明显大于面内裂缝。(2)浅埋煤层开采地表裂缝具有超前和滞后2种动态发育特征，其中，25213工作面开采诱发的地表裂缝滞后回采位置发育，滞后距6.49 m；15218工作面开采诱发的地表裂缝超前回采位置发育，超前距20.07 m；面内裂缝具有4种活动特征，边界裂缝宽度仅呈现“开裂—增大—稳定”的活动特征，地表裂缝整体活动时间4~14 d。(3)采空区地表附近形成压缩区、拉压转换区和拉伸区，随着工作面推进，采空区顶板岩层和地表移动变形破坏区不断向前扩展。地表下沉盆地范围略大于采空区，最大下沉系数0.82。(4)非贯通裂缝主要由地表移动盆地边缘土体拉伸变形超过其极限值所引起，贯通裂缝是覆岩内部上行裂缝与地表裂缝相接或直接导通地表的结果。随着工作面推采，基本顶周期破断引起地表裂缝向前不断扩展。地表裂缝宽度变化特征与裂缝两侧块体的复杂运动密切相关。研究成果对浅埋煤层开采区地表裂缝防治具有重要参考价值。

Surface cracks are recognized as one of the most common geologic hazards in coal mining areas in northern Shaanxi Province. These cracks directly cause damage to surface ecosystems. Furthermore, those penetrating fractures in the overburden act as primary channels for surface water to burst underground, threatening the safe production underground.

This study aims to further reveal the developmental patterns of surface cracks induced by the mining of shallowly buried coal seams and elucidate their formation and evolutionary mechanisms. To this end, this study investigated mining face 15218 and 25213 in the Hongliulin Coal Mine in northern Shaanxi. Specifically, the surface cracks in the mining face were comprehensively examined using methods including surface crack mapping, dynamic monitoring of cracks, and numerical simulations.

The results indicate that the surface cracks caused by the mining of shallowly buried coal seams exhibited a C-shaped distribution overall. The developmental characteristics and locations of the surface cracks were closely related to landform types. Under the same mining conditions, the proportion of cracks with widths greater than 5 cm in areas with loess gullies was 2.15 times that in areas with sandy beaches, suggesting a significantly higher developmental degree of cracks in the former areas than in the latter areas. Besides, the boundary cracks of the mining face exhibited a significantly higher developmental degree than cracks within the mining face. Surface cracks induced by the mining of shallowly buried coal seams manifested two dynamic developmental characteristics: ahead of and lagging behind mining positions. Among them, the formation of surface cracks induced by mining along mining face 25213 lagged behind the mining position, with a lag distance of 6.49 m. In contrast, surface cracks induced by mining along mining face 15218 were formed ahead of the mining position, with a lead distance of 20.07 m. Cracks within the mining face exhibited four activity characteristics, while the boundary cracks only showed an activity characteristic of cracking, increase in length, and stability sequentially. The surface cracks exhibited overall activity time ranging from 4 days to 14 days. Compression zones, tension-compression transform zones, and tensile zones were formed near the surface of the goaves. As the mining face advanced, movement deformation and failure zones within the roof strata and on the surface constantly expanded forward. The surface subsidence-induced basins were slightly larger than the goaves, with a maximum subsidence coefficient of 0.82. Non-penetrating cracks were primarily formed when the tensile deformations of soils along the margins of surface moving basins exceeded their limited values. In contrast, penetrating cracks were formed by the connection between upgoing cracks within the overburden and surface cracks or by the direct connection between the upgoing cracks and the surface. As the mining of the mining face advanced, the cycle rupture of the main roofs caused the surface cracks to continuously expand forward. The characteristics of variations in the surface crack width were closely related to the complex movement of blocks on both sides of the cracks. The results of this study can serve as an important reference for the prevention and control of surface cracks in the mining areas of shallowly buried coal seams.