摘要
N_2红土层是我国西北干旱-半干旱矿区广泛存在的、对保水采煤起关键作用的隔水层,为了研究釆动破裂N_2红土水土相互作用渗透性变化规律,在分析N_2红土矿物成分及膨胀性的基础上,采用自制的水土相互作用突水过程试验装置,定量化地研究了不同釆动破裂宽度N_2红土水土相互作用突水演化过程.研究结果表明:N_2红土的黏土矿物中亲水性矿物蒙脱石(含量达36%)、伊利石/蒙脱石混层(含量达18%)含量高,亲水性强,具有较强的膨胀性;釆动破裂N_2红土水土相互作用的初期裂缝周边松散颗粒堆积、裂缝边缘溃塌较为剧烈,裂缝闭合量较大,突水试验100 min中前15 min裂缝闭合量约占总闭合量的60%;突水量的变化可分为典型的3个阶段,即初期水量快速下降阶段、中期水量缓慢下降阶段和后期水量稳定阶段,裂缝宽度越大,突水稳定时间越长;釆动破裂N_2红土水土相互作用渗透性与时间呈负指数关系.
The laterite of Neogene pliocene series (N2),abbreviated as N2 laterite,over coal seams distributed widely in the mining area of western China is the key aquifuge soil for protecting the shallow water from being destroyed by coal mining. The permeability change induced by soil-water interactions of mining-cracked N2 laterite was studied. On the basis of analyzing the mineral composition and swelling properties of N2 laterite,the water inrush evolution process induced by soil-water interactions of mining-cracked N2 laterite was studied quantitatively using self-made experimental equipment. The results show that there is a high content of hydrophilic minerals in the clay minerals of N2 laterite, such as montmorillonite and illite/montmoduonite interstratified,therefore N2 laterite is more hydrophilic and has strong expansionary. During the early stages of soil-water interactions of mining-cracked N2 laterite, the accumulation of loose particles and the collapse of fracture edges were more intense,and the degree of fracture closure was larger. In the 100 minutes of the whole water inrush test,the amount of crack closure in the first 15 minutes accounts for about 60% of the total closure degree. In addition,the change of water inrush volume can be divided into three typical stages,namely,the rapid decline stage, the slow decline stage, and the stable stage. The greater the crack width is, the longer the water inrush stability time. The relationship between the permeability induced by soil-water interactions of miningcracked N2 laterite and time is a negative exponential relationship.
作者
王启庆
李文平
裴亚兵
吕城成
WANG Qiqing;LI Wenping;PEI Yabing;Lü Chengcheng(School of Resources and Geosciences,China University of Mining and Technology,Xuzhou 221116,China;Nuclear Industry Huzhou Engineering Surver Institute,Huzhou 313000,China)
出处
《西南交通大学学报》
EI
CSCD
北大核心
2019年第1期91-96,共6页
Journal of Southwest Jiaotong University
基金
国家自然科学基金重点资助项目(41430643)
关键词
N2红土
釆动破裂
水土相互作用
渗透性
N2 laterite
mining crack
soil-water interactions
permeability
