Seepage Analysis

HSWPE 4

A flow net was constructed for a homogeneous earth dam 52 m high and 2 m freeboard, and the following results were obtained. The number of potential drops = 25, Number of flow channels = 4. The dam has a horizontal filter of 40 m in length at its downstream end. Calculate the seepage discharge per meter length of the dam. Assume the dam material's permeability coefficient as 3x10^-3 cm/sec. (7 mark)

Answer: 

Given

K = 3x10^-3 cm/sec = 3x10^-5 m/sec

H = 52-2 = 50 m

Nf = 4

Nd = 25

There seepage discharge per meter length of the dam is 2.4×10^(−4) 𝑐𝑢𝑚𝑒𝑐𝑠/𝑚