水库挡水坝渗流边界问题

wangtiejun10

在水库挡水坝渗流分析中，具体见附件，AD上直接加降雨条件，BC不透水边界，AB边水位线以上我感觉应该用流量Q=0, CD边界以上应该加降雨，但感觉也不对，因为在靠近水位时的边界有降雨，也有可能水从此处渗出，不知道该怎么设置，希望版主，即高手指教，有对渗流感兴趣的朋友可以探讨，
我qq：402694331

basara

瞬态分析？初始条件是左右两侧定义的水头（水头为零点的连线是初始水位线？），计算降水水位线的抬升？如果是的话，AB边水位线以上部分不需要定义边界，由计算得到。

wangtiejun10

是瞬态分析，计算在降雨条件下孔压场地变化，我定义了cd水位线以上是流量检查边界，AB水位线以上是有可能渗流的，不设边界就是默认的不透水了，这样不合适吧

basara

参考算例 Road ditch ponding during rainfall
你需要理解的是边界定义的三个重要的fundamental
1 A very important point to note is that boundary conditions can only be one of two options. We can only specify either the H or the Q at a node.
2 Another very important concept you need to fully understand is that when you
specify H, the solution to the finite element Equation 5-1 will provide Q. Alternatively, when you specify Q, the solution will provide H.
3 A third important fundamental behavior that you need to fully understood is that when neither H nor Q is specified at a node, then the computed Q is zero.
你认为在AB边界应该指定流量还是水头？显然，在这一边界只能是流量为0的边界what it means is that the flow coming towards a node is the same as the flow leaving the node.

basara

Seepage faces 边界也是非常重要的一类型边界
situations where neither H nor Q are known. A typical situation is the development of a downstream seepage face. 计算原理 在计算开始时边界上的Q is zero，每次迭代计算，将边界上节点孔隙水压力为正的点处的边界改为压力边界H equal to the y-coordinate (zero water pressure)。At the end of the repeated solution step, water can now leave or enter the system at the nodes that were converted from a Q-type to an H-type.

这类边界可以分析得到出溢点。

哥萨克

Thanks for host's question and the 4#'s answers!!

lidongguang

学习学习，谢谢~~

qinrong_0305

正在学习中。。。