CE En 544 - Exam #1 - SEEPAGE KEY

Winter Semester 2018

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1. (1 pt each) True or False:

a. T F  (seep-goveq) A direct solution to the governing differential equation in the form of an equation or formula is called an analytical solution.

b. T F  (seep-analytical) A flow net consists of flow lines and pressure head contours.

c. T F  (seep-flownets) When considering flow nets for unconfined problems, the line of seepage (phreatic surface) corresponds to a flow line

d. T F  (seep-flownets) For anisotropic soils, the flow lines and equipotential lines will not necessarily intersect at right angles.

e. T F  (seep-head, darcy) Water cannot flow from a region of low pressure to a region of high pressure.

f. T F  (seep-welleq) The standard well equation for confined aquifers assumes that the flow is completely horizontal.

g. T F  (seep-finelem) The exit face boundary condition forces the pore pressure to be zero at all points along the exit face, assuming the points are below the exit point of the phreatic surface.

h. T F  (seep-finelem) Both the finite element and finite different methods result in a matrix of equations that is banded and symmetric.

i. T F  (seep-head, darcy) Pressure head at a point is the height that the water would rise in a standpipe inserted at the point, measured relative to the selected datum.

j. T F  (seep-head, darcy) When flowing perpendicular to the layers, the layer with the lowest k value has the largest impact on the flowrate through the system of layers.

k. T F  (seep-finelem) If you don't explicitly assign a boundary condition in SEEP2D, it is assumed to be a constant head boundary by default.

l. T F  (seep-flownets) For a flow net involving a sheetpile, the boundary corresponding to the sheetpile (down one side and up the other) represents an equipotential line.

m. T F  (seep-welleq) When deriving the equations for flow to a well in a confined aquifer, the Dupuit assumptions are not needed.

n. T F  (seep-goveq) For a confined aquifer, transmissivity is defined as the hydraulic conductivity divided by the thickness.

o. T F  (seep-head, darcy) The radius of influence (R) for a well is defined as the radius at which drawdown due to pumping at the well is negligible.