神府煤田风沙区采煤塌陷对粒度成分特征的影响

为了研究采煤塌陷对地表环境的粒度成分(机械组成)影响作用与过程,通过野外调查和取样,以神府煤田风沙区采煤塌陷1年、塌陷2年的塌陷区和非塌陷区(对照)为研究对象,采用对比法系统地分析了采煤塌陷区粒度变化特征。结果表明:塌陷1年、塌陷2年塌陷区粒度组成以粗沙和中沙为主,占整个组成的65%以上,非塌陷区以中沙和细沙为主,约占80%;多变量方差分析表明,塌陷1年、塌陷2年塌陷区粒径变化无明显差异存在,而与非塌陷区粒径变化有显著差异;塌陷区沙粒起动风速随着平均粒径的增大,以对数函数增加,而风蚀量与平均粒径的关系则随着起动风速的增大,以指数函数增大。塌陷1年、塌陷2年塌陷区粒度分布曲线均为双峰态,峰值出现在0.54 mm和0.125 mm处,众数组出现在0.63~0.45 mm和0.1~0.065 mm,而非塌陷区粒度分布曲线为单峰,其极值出现在0.125处。塌陷区地表(0~10 cm)范围内细粒和极细粒基本被风带走,地表颗粒呈现粗化现象,潜在的可风蚀性程度加强。

The Impact of Coal Mining Subsiding on Particle Size Composition in Shenfu Coalfield

In order to master the effects and the process of coal mining subsiding on particle size composition in the surface environment, this paper studied the particle size variations using contrast method in Shenfu coalfield based on field investigation and sampling analysis of subsiding one year, two years and no subsiding. The results indicated that the particles in one year subsiding area and two years subsiding area were mainly composed of coarse and medium sands as many as 65%, and the particles in no subsiding area was mainly composed of medium and fine sand as many as 80%. There was no significant difference in particle size variations between one year subsiding area and two years subsiding area, but the difference between subsiding and no subsiding areas was significant. With the increase of mean particle diameter, driving wind speed of blown sand in one year subsiding area and two years subsiding areas increased by logarithmic function; while with the increase of the driving wind speed, there was an exponential function relation between amount of wind erosion and mean particle diameter. The distribution curve of one year subsiding area and two years subsiding areas were both bimodal, the peak value was 0.54 mm and 0.125 mm. While the distribution curve of no subsiding area was single peak, and the peak value was 0.125 mm. The fine and very fine sands in the surface environment(0-10 cm depth) were basic gone by wind, the particle in surface present coarsening phenomenon, and the wind erosion possibilities intensified.