摘要
为了满足多级坝的安全稳定,必须了解尾矿库区排渗系统对渗流场的作用.通过构建特殊网格系统与子结构技术处理,在渗流有限元模型中实现了水平排渗管与纵横排渗盲沟的精细模拟,模型参数反演值与实测值具有较好拟合度.尾矿库区渗流数值模拟得出了填筑过程中(不同排渗条件)的渗流流速场、浸润面及水头分布.分析表明浸润面性态沿程不一致,在矿渣区水头变化平缓,在初期坝趾处渗透坡度急剧增加.排渗系统对降低渗压水头有明显作用,渗透坡度的降低程度与排渗管尺寸、盲沟布置有关,其大小则与尾矿坝填筑高度存在单调增函数关系.仅设置水平排渗管,最大坡降可降低8.7%—12.6%;管、沟结合的综合排渗系统能够调匀浸润面沿程性态,最大坡降可降低20.4%—43%,可以很好满足尾矿坝体的渗透稳定性要求.
In order to satisfy the safety and stability of the multistage dam, the action of drain seepage system must be understood in areas of tailing reservoir. By constructing a specific FEM element mesh and substructure technique, the combined drain system （horizontal drain pipe and blind ditch net）was well achieved in the model, and the simulating results were verified by the measuring results. Through the 3D seepage simulation in the tailing reservoir, the velocity field, phreatic surface and water head distribution had been obtained during different filling periods and with different drain seepage conditions. The analysis showed that phreatic line was varied along the valley from upstream to downstream of seepage field：where the seepage gradient changed relative mildly in slag accumulative area, and rised steeply in the initial dam toe. The drain system can reduce seepage head obviously. The seepage gradient has relations with size of drain pipe and arrangement of drainage ditch; it also presented monotone increase relevance with the effective water head of multistage dam. As the increase of the filling height, the seepage gradient increased correspondingly and decreased with a perfect draining measure. Only adapt horizontal drain pipe, maximum seepage gradient could be reduced 8. 7%-12. 6%. The combine system（ pipe ＋ ditch）could harmonize the properties of phreatic surface, and reduced gradient 20.4% -43.0%, so that it can well meets the stability requirements of the multistage dams.
出处
《应用基础与工程科学学报》
EI
CSCD
北大核心
2013年第3期532-543,共12页
Journal of Basic Science and Engineering
基金
国家自然科学基金(51079055)
中央高校基本科研业务费专项资金资助(2012210020202)
关键词
尾矿坝
子结构
排渗系统
填筑期
渗透坡度
tailing dam
substructure
drain seepage system
filling period
seepage gradient
