Flow Net Applications – What Can Be Determined from a Properly Drawn Net? A correctly constructed flow net for seepage through a homogeneous, isotropic soil can be used to determine which of the following quantities?

Introduction / Context:
Flow nets graphically solve Laplace’s equation for two-dimensional, steady, incompressible flow through porous media. They are extensively used in the analysis of earth dams, sheet piles, and cutoff walls to estimate uplift, piping potential, and seepage quantities.

Given Data / Assumptions:

• Soil is homogeneous and isotropic in the plane of analysis.
• Steady-state flow; boundary conditions defined by impervious and constant-head lines.
• Flow net composed of orthogonal flow lines and equipotentials forming curvilinear squares.

Concept / Approach:

Once the net is drawn, the discharge per unit thickness is q = k * (N_f / N_d) * Δh, where N_f is number of flow channels and N_d is number of potential drops. Pore pressure at any point follows from the potential head at that equipotential. Seepage pressure equals γ_w times the head loss per distance along the flow line. The exit gradient is the head loss across the last potential drop divided by the distance to the outlet, read from the net geometry.

Step-by-Step Solution:

Verification / Alternative check:

Comparisons with finite element seepage models show good agreement when the net satisfies curvilinear-square quality.

Why Other Options Are Wrong:

Each item is a legitimate outcome of a valid net; omitting any would be incomplete, so 'All of the above' is correct.

Common Pitfalls:

Drawing distorted elements that are not near squares; miscounting flow channels or potential drops; applying the method to anisotropic soils without transforming axes.

Final Answer:

All of the above