This study experimentally examined the performance of pooled stilling basins with positive and negative steps,
with and without baffle blocks, for mitigating local scour and enhancing energy dissipation downstream of sluice
gates. The study combined 1, 2, and 3 negative steps with 1, 2, 3, and 4 positive steps. Additionally, the experimental
setup included the investigation of adding 1, 2, or 3 rows of baffle blocks, with each row configuration being
tested at three different vertical height specifications. Experiments were conducted in a 15.6 m long, 0.30 m wide,
and 0.468 m deep recirculating flume at Froude numbers 1.0 to 2.0 under a fixed submergence ratio ( sr = 3.3). A 2.0 m
long and 0.1 m deep mobile sand bed was installed downstream of the basin. A total of 12 models with 81 test runs,
were examined in the laboratory under various flow conditions. Results showed that steeped basin, model C1 (two
negative steps followed by four positive steps), reduced scour by up to 48%. Adding baffle blocks; with the tallest
blocks ( E2,hb
K =1.5) and blockage ratio of 5%, further increased the reduction to 54%. Energy dissipation improved
by up to 59% for model B4 (one negative step followed by four positive steps). Adding single row configurations
of baffles with blockage area 5% and relative height ( hb
K =1) provided the most efficient balance between scour reduction
and energy loss. Finally, experimental data are used to derive empirical formulas through multiple linear regression
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