峰峰新三矿煤矸石山土壤水分特性研究

Study on the Soil Water Characteristics of the Coal Gangue Piles in the Xinsan Mine in Fengfeng Mine Field

为了解煤矸石基质土壤的水分特性,为煤矸石山水土保持、生态修复和复垦提供理论依据,试验选用峰峰新三矿6种不同煤矸石基质土壤,采用室内模拟试验的方法,测定土壤孔隙度、渗透系数和水分入渗规律。试验结果表明:混合基质土壤孔隙度随掺土比例的增大而增大,掺土后基质总孔隙度显著增加;基质土壤的渗透系数山脚>山腰>山顶;矸土比为7∶3、5∶5和3∶7的混合基质土壤的渗透系数分别是原矸石的0.643、0.517和0.459,掺土后渗透系数显著降低。山脚矸石的初始入渗率和稳渗率分别为山腰的1.111和1.078倍;山腰矸石的初始入渗率和稳渗率分别为山顶的1.096和1.102倍;矸∶土/7∶3的初始入渗率和稳渗率分别为5∶5的1.152和1.149倍;矸土比5∶5的初始入渗率和稳渗率分别为矸土比3∶7的1.179和1.057倍。矸土混合土壤的初始入渗率、稳渗率均随矸土比的减小而迅速减小,入渗达到稳定状态的时间随矸土比的减小而增加。Kostiakov入渗模型更适合作为风化煤矸石的入渗模型,通用经验模型更适合作为掺土煤矸石的入渗模型。矸石掺土可以显著降低入渗率,提高累积入渗量,有益于煤矸石山的植物生长。

In order to realize the moisture characteristics of soil weathering coal gangue and research the water retention parameters such as porosity,permeability coefficient,water characteristic curve and infiltration characteristics,the indoor simulation experiments were conducted with soil weathering coal waste from the Xinsan mine in Fengfeng coal field. The results show that the porosity ratio of mixed soil increases significantly with the increase of loess. The permeability coefficient of gangue soil is pile-foot mid-pile pile top. The permeability coefficient of mixed soil 7∶ 3,5∶ 5 and 3∶ 7 is respectively 0. 643,0. 517,0. 459 times of the weathering gangues,and the permeability coefficient of soil mixed is decreasing obviously. The initial and stable infiltration rate of pile-foot gangue were 1. 111 and 1. 078 times higher than that of the gangue at mid-slope; the initial and stable infiltration rate of the gangue at mid-slope were 1. 096 and 1. 102 times higher than that of the gangue at pile top. The initial and stable infiltration rate of gangue with ratio of gangue to loess 7∶ 3 was 1. 152 times and 1. 149 times higher than that of5∶ 5; The initial infiltration rate and infiltration rate of gangue with ratio of gangue to loess 5∶ 5 was 1. 179 times and1. 057 times higher than that of 3∶ 7. As the infiltration time increased,in the same interval,cumulative infiltration volume increased with the increasing quantity of large particles but the more the quantity of granules,the longer the time of wetting front arrival. The Kostiakov model is more suitable for the infiltration model of coal gangue from pile top to pile-foot area,and the general empirical model is more suitable for the infiltration model of coal gangue when the weight ratio of the ratio of gangue soil is small. The cumulated infiltration of gangue is higher at the pile top,water holding ability is strong,and correlation coefficient is higher than 0. 92. Overall mixing soil water curves is higher and holding capacity is stronger. During the coal gangue reclamation,the adding of loess is beneficial to water holding ability and the growth of plants.