彬长矿区采陷裂缝影响因素分析

Analysis of Mining-induced Crack Characteristics and Contributing Factors in Binchang Mining Area

对彬长矿区地面裂缝进行了详细调查,指出该矿区地面裂缝的主要为开采塌陷引起的采陷裂缝,并对采陷裂缝的发育特征进行了归类。分析认为:采深增大,基岩厚度增大,覆岩的稳定性增强,对地面裂缝的规模控制也增强,60°～70°为塌陷裂缝边界范围圈定的指标值;工作面变宽,采厚变大,会加剧地面裂缝的产生和发展;"上硬下软"的地层结构,有利控制地表移动变形,关键层厚度增大,可以明显减缓地表移动;松散层厚度愈大,抗变形能力愈大的土层,其裂缝愈不发育;V型沟谷对裂缝的形成和发展影响较小,斜坡则对裂缝的发育有加剧作用;降雨对裂缝的发育有明显的加速作用。

Detailed investigation has carried out on surface cracks in the Binchang mining area, pointed out that the surface cracks in the mining area are mainly mining-induced cracks because of mining subsidence, and sorting out mining-induced crack development characteristics. The analysis considered that： along with mining depth increasing, bedrock thickness, overburden stability and surface crack scope controlling are also increased, 60o-70o is the targeted value for subsidence crack boundary delineation. Working face widening, working thickness increasing will intensify surface crack producing and development. The strata configuration of ＂upper hard, lower soft＂ is in favor of to control surface movement and deformation, increasing of key strata thickness can relief surface movement obviously. Soil horizon with larger thickness and larger non-deformability will be developed with lesser cracks. Impact to crack formation and development from V-typed ravines is smaller, while slope will prick up crack development. Rainfall accelerates crack development obviously.