摘要
用具有不同尺寸的裂隙的混凝土预制块模拟采动裂缝岩体,以粘土、粉土、粗砂和砾砂为基本材料配制21种土样模拟松散层,采用改装的渗透仪,对采区上覆垮落带和裂缝带之上的这种松散层发生渗透变形破坏的类型和机理进行了研究,得出了水往裂隙带方向流动时松散层发生渗透变形破坏的临界水力坡度与土层粒度成分、物理力学性质和裂隙尺寸等的关系。试验表明,粘粒含量少的粉土、粗砂、砾砂较易发生水砂突涌;同一种土样发生渗透变形破坏时,裂缝宽度越大,临界水力坡度越小。试验还得出了突砂口张开程度与突砂量的关系。
Concrete blocks with fissures of different sizes are adopted to simulate mining fractured rock mass, and the clay, sih, coarse sand and gravel are used to compose 21 kinds of soil samples with different particle size distributions. Then, the types and mechanisms of the seepage deformation and failure of the unconsolidated soil layers across the caving zone and water flowing fractured zone within overburden, and the relationship between the critical percolation gradient of unconsolidated soil layers while seepage failure across mining-induced fissures from above to bellow vertically, soil particle size distributions, physical and mechanical properties and the widths of fissures are studied in laboratory tests by reequipped seepage meters. The results show that the silt, coarse sand and gravel with small amount of clay are easier to quicksand. The wider the fissures are, the smaller the critical percolation gradient for the same soil sample is when seepage failure deformation occurs across fissures, and the critical percolation gradient decreases exponentially with the extension of the width of fissures. So it can be deduced that the width of fissures are the key factors controlling the amount of the quicksand.
出处
《水文地质工程地质》
CAS
CSCD
北大核心
2008年第6期66-69,共4页
Hydrogeology & Engineering Geology
关键词
采煤
渗透破坏
水力坡度
覆岩破坏
coal mining
seepage failure
hydraulic gradient
overburden failure
