1 Hydraulic ModelingSluice canal downstream of the weir is modeled by a one dimension hydraulic model program (HEC-RAS).The model starts upstream just after the weir vertical wall and ends 100 meters after the end of the weirsluice canal. Hatched area shows the area modeled, to get an extreme velocity for design the upstreamboundary condition discharge, and the downstream boundary condition set to be at critical water surface.

Figure 1. Weir location and model boundaryThe discharge at the upstream of the model is set to be at 30 m/sec. Water surface profile in the modelare shown in Figure 2. At sta 100 the sudden expansion from sluice canal to the weir downstream takesplace.

Figure 2. Water surface profileAverage velocity are shown in Figure 3 below.

50,0

0

55,0

0

55,0

0

1:1,

5

1:1,

510,60

22,25

30,00

8,15

7,50

24,2

6

108,

21

27,35

77,3

2

19,45 15,00

30,00

0 20 40 60 80 100 120 140 160404

406

408

410

412

414

416

418

420

422

outlet sluice weir Plan: Plan 01 6/16/2015

Main Channel Distance (m)

Elev

atio

n (m

)

Legend

EG PF 1

WS PF 1

Crit PF 1

Ground

1 1

Figure 3. Velocity profileWith the velocity of 0.82 m/sec, the designed rip rap diameter of 40 cm minimum should suffice to ensureno bed load transport happens. With the numbers above in the hjulstrom chart falls in the depositionarea.

Figure 4. Sediment transport chart (hjulstrom, 1957)

0 20 40 60 80 100 120 140 1600

1

2

3

4

5

outlet sluice weir Plan: Plan 01 6/16/2015

Main Channel Distance (m)

Vel L

eft (

m/s

), Ve

l Chn

l (m

/s),

Vel R

ight

(m/s

)

Legend

Vel Chnl PF 1

1 1

Section after sluicecanal, V= 0.82 m/sec