Seepage Flow Rate
Seepage Flow Rate
The volume of water seeping through a soil body follows Darcy’s law applied over the flow area — key for dams and excavations.
The flow rate is Q = k·i·A. where k is the permeability, i the hydraulic gradient and A the flow area.
Inputs
k := 1e-5 m/s=1e-05 m/s
i := 0.4=0.4
A := 20 m^2=20 m^2
Apply Darcy’s law over the flow area.
Q := k·i·A=8e-05 m^3/s
Results
This seepage must be collected and drained; excessive gradients can also trigger piping (internal erosion) in dams and cofferdams.
Assumptions & limitations
- Darcy (laminar) flow.
- Saturated, homogeneous soil.
- Steady seepage.