796455_P1043_FinalDrawings_Vol_8.pdf

Outlet Pipe Diameter

(D) (Inches)

Maximum Pipe

Discharge (Q, cfs)

Velocity (V, fps)

Minimum Apron Length

(La) (Ft.)

Minimum Apron

Width (W) (Ft.)

Minimum Apron

Thickness (d)

(Ft.)

Median Stone Size d50

Ft.)

Maximum Tailwater

Depth (ft)

NCDOT

Rip Rap

15 6.1 5 8 9.25 1 0.5 1.1 Class A 18 8.8 5 9 10.5 1 0.5 1.4 Class A 24 15.7 5 13 15 1 0.5 1.7 Class A 30 24.5 5 16 18.5 1 0.5 2.1 Class A

UNDEFINED DISCHARGE CHANNEL

Outlet Pipe Diameter

(d (Inches)

Maximum Pipe

Discharge (Q, cfs)

Velocity (V, fps)

Minimum Apron Length

(La) (Ft.)

Minimum Apron

Width (W) (Ft.)

Minimum Apron

Thickness (d)

(Ft.)

Median Stone Size d50

Ft.)

Maximum Tailwater

Depth (ft)

NCDOT

Rip Rap

15 6.1 5 7 4 1 0.5 1.1 Class A 18 8.8 5 7 4.5 1 0.5 1.4 Class A 24 15.7 5 9 6 1 0.5 1.7 Class A 30 24.5 5 11 7 1 0.5 2.1 Class A

WELL DEFINED DISCHARGE CHANNEL

1. ENSURE THAT THE SUBGRADE FOR THE FILTER AND RIPRAP FOLLOWS THE REQUIRED LINES AND

GRADES SHOWN IN THE PLAN. COMPACT ANY FILL REQUIRED IN THE SUBGRADE TO THE DENSITY OF

THE SURROUNDING UNDISTURBED MATERIAL. LOW AREAS IN THE SUBGRADE ON UNDISTURBED SOIL

MAY ALSO BE FILLED BY INCREASING THE RIPRAP THICKNESS.

2. THE RIPRAP MUST CONFORM TO THE SPECIFIED GRADING LIMITS SHOWN ON THE PLANS.

3. FILTER CLOTH, MUST MEET DESIGN REQUIREMENTS AND BE PROPERLY PROTECTED FROM

PUNCHING OR TEARING DURING INSTALLATION. REPAIR ANY DAMAGE BY REMOVING THE RIPRAP AND

PLACING ANOTHER PIECE OF FILTER CLOTH OVER THE DAMAGED AREA. ALL CONNECTING JOINTS MUST

OVERLAP SO THE TOP LAYER IS ABOVE THE DOWNSTREAM LAYER A MINIMUM OF 1 FOOT. IF THE

DAMAGE IS EXTENSIVE, REPLACE THE ENTIRE FILTER CLOTH.

4. RIPRAP MAY BE PLACED BY EQUIPMENT, BUT TAKE CARE TO AVOID DAMAGING THE FILTER.

5. THE MINIMUM THICKNESS OF THE RIPRAP MUST BE 1.5 TIMES THE MAXIMUM STONE DIAMETER.

6. RIPRAP MAY BE FIELD STONE OR ROUGH QUARRY STONE. IT MUST BE HARD, ANGULAR, HIGHLY

WEATHER‐RESISTANT AND WELL GRADED.

7. CONSTRUCT THE APRON ON ZERO GRADE WITH NO OVERFILL AT THE END. MAKE THE TOP OF THE

RIPRAP AT THE DOWNSTREAM END LEVEL WITH THE RECEIVING AREA OR SLIGHTLY BELOW IT.

8. ENSURE THAT THE APRON IS PROPERLY ALIGNED WITH THE RECEIVING STREAM AND PREFERABLY

STRAIGHT THROUGHOUT ITS LENGTH. IF A CURVE IS NEEDED TO FIT SITE CONDITIONS, PLACE IT IN THE

UPPER SECTION OF THE APRON.

9. IMMEDIATELY AFTER CONSTRUCTION, STABILIZE ALL DISTURBED AREAS WITH VEGETATION

(PRACTICES 6.10, TEMPORARY SEEDING, AND 6.11, PERMANENT SEEDING).

1 2 3

2.50 1.50 2.50

4,588 2,953 4,588

4,500 2,700 4,500

24 X 58 28 X 56 24 X 58

34 X 68 18 X 46 34 X 68

3:1 3:1 3:1

23.5 36.0 29.0

22.5 25.0 28.0

21.5 24.0 27.0

20.0 22.5 25.5

5 5 5

WEIR LENGTH (FT) 6 4 6

2 2 2

ORIFICE DIAMETER (IN) 1.25 1.00 1.25

15 15 15

45 75 75

0.01 0.01 0.01

BARREL DIAMETER (IN)

BARREL LENGTH (FT)

BARREL MINIMUM SLOPE (FT/FT)

STORAGE LEVEL ELEVATION

INVERT SKIMMER ‐ TOP OF SEDIMENT STORAGE

EMBANKMENT WIDTH (FT)

SKIMMER DIAMETER (IN)

BASIN BOTTOM ELEVATION

BASIN BOTTOM DIMENSIONS (FT)

BASIN TOP DIMENSIONS (FT)

SIDE SLOPE

RIM ELEVATION

SKIMMER SEDIMENT BASIN

DRAINAGE AREA (AC)

STORAGE PROVIDED (CF)

STORAGE REQUIRED (CF)

0.50

2,133

1,800

4 X 29

3:1

3.5

1,250

WEIR LENGTH (FT) 2

0.5

SEDIMENT TRAP

TOP SURFACE AREA (SF)

DEPTH OF FLOW (FT)

BASIN BOTTOM DIMENSIONS (FT)

BOTTOM AREA (SF)

SIDE SLOPE

DEPTH (FT)

DRAINAGE AREA (AC)

STORAGE PROVIDED (CF)

STORAGE REQUIRED (CF)