水库水位升降影响下库岸裂隙岩体渗流特性分析  

Seepage features in bank fractured rock mass under the influence of reservoir upstream water level rising or drawdown

作　　者：张彦洪[1,2] 柴军瑞[1,3] 

机构地区：[1]西安理工大学水利水电学院,西安710048 [2]甘肃农业大学水利水电工程系,兰州730070 [3]三峡大学土木水电学院,湖北宜昌443002

出　　处：《工程勘察》2010年第5期26-30,73,共6页Geotechnical Investigation & Surveying

基　　金：国家自然科学基金项目(50579092);"楚天学者计划"特聘教授资助项目(603108)

摘　　要：水力边界变化对边坡岩体渗流应力状态以及岩体稳定性具有重要影响。本文应用离散裂隙网络非稳定渗流模型,分析水库水位升降运行方式对岩质边坡内渗流场的影响,探求裂隙岩体内部水头分布与边界水位之间的关系。分析表明,水库水位升降变化时,边坡岩体渗流场中水头改变存在滞后效应,滞后程度与水位变化速度、研究点距变化边界的距离、以及裂隙的连通性等密切相关。水库水位和运行方式是影响裂隙岩体渗流场分布的主要因素。水库水位单向匀速上升(下降)或连续等速升降时,裂隙岩体渗流场主要决定于边界水位值。水库水位非等速连续升降变化时,岩体渗流场主要决定于水位升降速度之差以及节点位置。如果采用慢蓄快泄的运行方式,将在岩体内形成较大的渗透动水压力,降低岩体的稳定性。Variation of hydraulic boundary has an important influence on the seepage feature,stress status and rock slope stability in reservoir engineering.In this paper,by using the discrete fracture network unsteady seepage model,the effect put on flow fields in rock slope by reservoir water table going up or down is analyzed,and the distribution characteristics of hydraulic head in rock mass varies with boundary water level is studied too.The results show when upstream water level changes vertically,the variation of hydraulic head in rock mass may displays delayed effect,and the delayed extent of hydraulic head in rock mass closely related with such factors as velocity of water level changing,location of the studied nodes and connectivity of fissures.Both water level and its way of operation are the two primary factors decide seepage fields.When water table other changing only in one direction or going up and falling continuously with the same velocity,the seepage field is mainly dominated by the boundary water level.But when the speed of water table rising greatly different to that of drawdown,the features of seepage field correlate closely to the difference of speed between water level rising and drawdown and position of nodes in rock mass.If reservoir runs in the way of sluice fast but storage slow,it will produce huge hydrodynamic pressure in rock mass slope and may lower its stability.

关 键 词：岩体水力学 水位升降 水头分布 裂隙岩体 滞后效应 

分 类 号：TV122[水利工程—水文学及水资源]