The hydraulic structures (dams, barrages, regulators…..) are
complicated constructions and need an accurate technical and
economical visibility studies; prepare design, execution and effective
technique to be followed for maintenance.
The percolation length is one of the most important items controlling the
design of the water structures especially for apron length and thickness
Seepage under the apron of the hydraulic structures was controlled by
providing the apron with row or more of steel piles , but the sheet piles
now is very high costs comparing by others options at the same time, and
to improve the apron conditions of the old structure, the sheet piles is not
possible to implement.
In present paper, an apron with multiple rows of relief wells starting by
one row of relief wells till six rows of relief wells were put under testing
in different arrangements .
An analog model was used with variable depths and distances between
the relief wells rows in different arrangements. 96 runs were performed
for one row of relief wells case, 84 runs were performed for two rows of
wells case, 72 runs for three rows of relief wells case, 60 runs were
performed for four rows of relief well case, 48 runs were done in five
rows of relief case and 36 runs were performed in six rows of relief wells
case. 429 reading node for every test run are recorded and plotted by
using the surfer software.
The conclusions, from the analysis of the obtained model results was as
follows: The effective position in the potential of apron exit edge located
near the edge of the apron for six rows of relief wells rows at (20%-30%-
40%-50%-60%-80%)Lap respectively, measured from upstream of an
apron. The effective percentage reduced in potential of the apron exit
edge is 73% and located at the 80% from the apron total length for six
rows of relief wells (20-30-40-50-60-80). The efficiency of the U.S. relief
wells is greater than that for the D.S. relief wells.