单 位：
华北水利水电大学水利学院;洛阳水利勘测设计有限责任公司
关键词：
非稳定渗流;非饱和土;基质吸力;水力梯度;渗透破坏
摘 要：
为了研究非稳定渗流对坝体非饱和土体水力梯度的动态变化影响,考虑土体基质吸力与体积含水量的变化关系,建立了非饱和土体的渗流运动微分方程.采用SEEP/W软件对均质土坝在水位降落和上升等工况下的瞬时渗流场进行数值模拟,分析坝体上游侧、下游侧等不同深度的水力梯度变化值,以探寻坝体不同部位水力梯度在整个渗流历时内的动态变化规律及其可能发生渗透破坏的主要时间段.数值模拟结果表明:上游侧坝体底部水力梯度会在骤降历时的60%~70%时间段内出现高出稳定渗流期36.4倍的峰值,是最易引发渗流破坏的时间段;坝体上游侧水位变动区土体的水力梯度在上升历时的25%~50%时间段内增加较慢,在50%时间段后迅速增加,增加幅度达30~50倍,水位上升历时的50%时间段之后是其发生水力渗透破坏的主要时间段;水位升降对坝体下游侧土体水力梯度的影响甚微.计算结果可为大坝的调洪运行管理提供可参考的决策依据.
译 名：
Time-varying analysis on hydraulic gradient for non-saturated soil in transient seepage
作 者：
Xu Cundong;Zhang Shuo;Shi Guokun;Chang Zhoumei;School of Water Conservancy,North China University of Water Resources and Electric Power;Luoyang Water Resources Surveying & Designing Co. Ltd.;
关键词：
transient seepage;;non-saturated soil;;matric suction;;hydraulic gradient;;seepage failure
摘 要：
To study the dynamic change of hydraulic gradient non-saturated in transient seepage,the differential equation of non-saturated seepage flow was established,and the relationship of matric suction and volumetric-water content was also taken into account in the equation. SEEP / W software was applied on simulating the seepage field in drawdown process and rise process,the change of hydraulic gradient at different depth was analyzed for exploring the rule of hydraulic gradient in different dam parts and the main periods of seepage failure. The simulation results show that hydraulic gradient at upstream side of the bottom,when sudden drawdown at 60%- 70% of process,appears a peak which is 36. 4 times than stable seepage period,it is the main periods of seepage failure. For the non-saturated soil at the upstream side of dam,hydraulic gradient increases slowly at 25%- 50% of the water level rising period,but increases to 30- 50 times rapidly after 50% of period,so it is the main period of seepage failure after 50% of slowly rising period. Variation of water level has almost no effect on the downstream. The results can provide a decision-making reference for flood regulation and operation management.
