采煤沉陷区包气带土壤水力参数测定及特征分析

Analysis of Hydraulic Parameters and Characteristics for Soil of Unsaturated Zone in Mining Subsidence Area

为研究矿山采煤沉陷中的裂隙对包气带土壤水力参数影响,通过对淮南潘一煤矿沉陷区包气带土壤颗粒组成、水分特征曲线(SWCCs)和非饱和导水率曲线(UHCCs)测试分析,并与非沉陷区进行对比分析讨论。结果表明:处于稳沉阶段的沉陷区,其裂隙对包气带土壤水力参数产生影响表现为沉陷作用降低了包气带SWCCs斜率,且地表深部隐伏裂隙减小了SWCCs中的进气值,导致沉陷区包气带土壤释水能力增大;UHCCs测定分析表明,在相同基质势作用下,沉陷区土壤UHCCs明显低于对照组,由于沉陷产生的裂隙中的水最先被排空,形成不导水的空隙,导致非饱和导水率下降。研究结果为沉陷区水分运移试验研究提供一定理论与指导。

To study the variation of hydraulic parameters of unsaturated zone in the coal mining subsidence cracks region,the soil particle size distribution,soil water characteristic curves(SWCCs)and unsaturated hydraulic conductivity curves(UHCCs)were measured and analyzed in PanJi coal mining subsidence area in Huainan compared with the no-Subslihen cearea.The results showed that the hydraulic parameters of unsaturated zone chagend continuously in the coal mining subsidence in steady phase,and subsidence fissures had reduced the slope of the SWCCs and the SWCCs air entry value,and then resulted in higher water-holding capacity.Under the same matrix potential,the UHCCs of subsidence area soil significantly is lower than that of the non-subsidence area.This was due to the precedence flow in subsidence fissure,which would produce non-water-conductive fissure zone and resulted in the decrease of moisture content and hydraulic conductivity.All the results above will provide significant basis for experimental studies in water movement process of unsaturated zone in coal mining subsidence region.