PRELIMINARY CULVERT ANALYSIS REPORT FOR CULVERT NO. 008-C OREGON AVENUE OVER PINEHURST CREEK

Transcription

1 PRELIMINARY CULVERT ANALYSIS REPORT FOR CULVERT NO. 008-C OREGON AVENUE OVER PINEHURST CREEK Prepared for The District of Columbia Department of Transportation Washington, D.C. Prepared by Parsons Transportation Group 100 M Street, SE Washington, DC SEPTEMBER 2010

2 TABLE OF CONTENTS 1.0 LOCATION MAP DESCRIPTION DESIGN STANDARDS AND CRITERIA EXISTING CONDITONS PROPOSED CONDITIONS HY 8 CULVERT ANALYSIS REPORT PHOTOS

3 1.0 LOCATION MAP 3

4 2.0 DESCRIPTION The existing Oregon Avenue Project is bounded by Military Road on the South and Western Avenue on the North. The existing culvert consists of singular rectangular concrete barrel of varying in size over Pinehurst Creek with two lanes of traffic. This structure is nearly 34 long and 14 6 x 4 6 at inlet and x 5 7 at outlet as per inspection report prepared by Wilbur Smith Associates, Falls Church, VA dated 07/18/03. The purpose of this report is to analyze the existing conditions of the culvert and check the adequacy. This report will identify the existing culvert issues and provide a basis for future improvement. 3.0 DESIGN STANDARDS AND CRITERIA The existing culvert is analyzed in accordance with Chapter 23 and 33 of the District of Columbia Department of Transportation (DDOT) Design and Engineering Manual and the Federal Emergency Management Agency (FEMA), District of Columbia Washington DC. The culvert is in floodplain and analyzed using 50 year storm draining to low point in sag. In compliance with the National Flood Insurance Program (NFIP) it is necessary to consider 100 year frequency flood at all locations where construction will encroach on a floodplain. The NFIP prohibits any construction in floodplains, when combined with all other existing and anticipated uses, which would increase the water surface elevation of 100 year flood more than one foot at any given point. This does not necessarily require that the culvert be sized to pass the 100 year flood, provided the capacity of the culvert plus flow bypassing the culvert is sufficient to accommodate the 100 year flood without raising the water surface elevation excessively. Following are the summary of data for Pinehurst Run upstream of Oregon Avenue from Flood Insurance Study, Federal Emergency Management Agency, District of Columbia Washington DC dated August 16, Drainage Area (sqmi) year flood (cfs) year flood (cfs) year flood (cfs) year flood (cfs) year elevation (ft) 100 year elevation (ft) (From Flood Profile) (From Flood Profile) 4

5 4.0 EXISTING CONDITONS Existing culvert (size 14 6 X 4 6 ) is analyzed, considering 3.5 height parapet wall above the culvert, by using HY 8 and results are provided in end of this this report. From table 1, headwater elevation for design discharge (1580 cfs) is ft, discharge through culvert is cfs and roadway discharge is cfs. Headwater elevation for 100 year flood (1805 cfs) is ft which is less than ft. It is observed that there is significant scouring on downstream of the culvert and outlet velocity is ft/s for design discharge from table 2. Existing culvert has supercritical flow and function under inlet control. 5.0 PROPOSED CONDITIONS A triple barrel box culvert in different conditions and size with same length and parapet wall is recommended and analyses are provided on this report. It is assumed that road surface will be raised by 1.5 in proposed condition. From table 4, the headwater elevation for design discharge (1580 cfs) is ft, discharge through culvert is cfs and roadway discharge is 0.00 cfs. It shows that 50 year flood passes through culvert without overtopping road. Headwater elevation for 100 year flood (1805 cfs) is ft which is less than ft. A class II dry Riprap mat (L=30, W=60 & T=36 ) is recommended for downstream protection of the culvert because outlet velocity is ft/s for design discharge from table 5. Proposed culvert will have supercritical flow and will be functioning under inlet control. 5

6 6.0 HY 8 CULVERT ANALYSIS REPORT 6

7 Table 1 - Summary of Culvert Flows at Crossing: Exist Culvert Headwater Elevation (ft) Total Discharge (cfs) Exist-1 Discharge (cfs) Roadway Discharge (cfs) Iterations Overtopping 7

8 Rating Curve Plot for Crossing: Exist Culvert 8

9 Table 2 - Culvert Summary Table: Exist-1 Total Discharge (cfs) Culvert Discharge (cfs) Headwater Elevation (ft) Inlet Control Depth (ft) Outlet Control Depth (ft) Flow Type Normal Depth (ft) Critical Depth (ft) Outlet Depth (ft) Tailwater Depth (ft) Outlet Velocity (ft/s) Tailwater Velocity (ft/s) * 0-NF * 1-S2n * 1-S2n * 5-S2n * 5-S2n * 5-S2n * 5-S2n * 5-S2n * 5-S2n S2n S2n

10 * theoretical depth is impractical. Depth reported is corrected. ******************************************************************************** Inlet Elevation (invert): ft, Outlet Elevation (invert): ft Culvert Length: ft, Culvert Slope: ******************************************************************************** 10

11 Culvert Performance Curve Plot: Exist-1 11

12 Water Surface Profile Plot for Culvert: Exist-1 Site Data - Exist-1 Site Data Option: Culvert Invert Data Inlet Station: ft Inlet Elevation: ft Outlet Station: ft Outlet Elevation: ft Number of Barrels: 1 Culvert Data Summary - Exist-1 Barrel Shape: Concrete Box Barrel Span: ft Barrel Rise: 4.60 ft Barrel Material: Concrete Embedment: 0.00 in Barrel Manning's n: Inlet Type: Conventional Inlet Edge Condition: Square Edge (90º) Headwall 12

13 Inlet Depression: None 13

14 Table 3 - Downstream Channel Rating Curve (Crossing: Exist Culvert) Flow (cfs) Water Surface Elev (ft) Depth (ft) Velocity (ft/s) Shear (psf) Froude Number Tailwater Channel Data - Exist Culvert Tailwater Channel Option: Irregular Channel Channel Slope: User Defined Channel Cross-Section: Coord No. Station (ft) Elevation (ft) Manning's n Roadway Data for Crossing: Exist Culvert Roadway Profile Shape: Irregular Roadway Shape (coordinates) 14

15 Irregular Roadway Cross-Section: Coord No. Station (ft) Elevation (ft) Roadway Surface: Paved Roadway Top Width: ft 15

16 Crossing Front View (Roadway Profile): Exist Culvert 50 Yr HW Parapet wall Exist Culvert Road Profile 16

17 Table 4 - Flows at Crossing: Prop Culvert-1 Headwater Elevation (ft) Total Discharge (cfs) Prop- No Overtopping Discharge (cfs) Roadway Discharge (cfs) Iterations Overtopping 17

18 Rating Curve Plot for Crossing: Prop Culvert-1 18

19 Table 5 - Culvert Summary Table: Prop- No Overtopping Total Discharge (cfs) Culvert Discharge (cfs) Headwater Elevation (ft) Inlet Control Depth (ft) Outlet Control Depth (ft) Flow Type Normal Depth (ft) Critical Depth (ft) Outlet Depth (ft) Tailwater Depth (ft) Outlet Velocity (ft/s) Tailwater Velocity (ft/s) * 0-NF * 1-S2n * 1-S2n * 1-S2n * 1-S2n * 1-S2n * 1-S2n * 5-S2n * 5-S2n S2n S2n

20 * theoretical depth is impractical. Depth reported is corrected. ******************************************************************************** Inlet Elevation (invert): ft, Outlet Elevation (invert): ft Culvert Length: ft, Culvert Slope: ******************************************************************************** 20

21 Culvert Performance Curve Plot: Prop- No Overtopping 21

22 Water Surface Profile Plot for Culvert: Prop- No Overtopping Site Data - Prop- No Overtopping Site Data Option: Culvert Invert Data Inlet Station: ft Inlet Elevation: ft Outlet Station: ft Outlet Elevation: ft Number of Barrels: 3 Culvert Data Summary - Prop- No Overtopping Barrel Shape: Concrete Box Barrel Span: ft Barrel Rise: 6.00 ft Barrel Material: Concrete Embedment: 0.00 in Barrel Manning's n: Inlet Type: Conventional Inlet Edge Condition: Square Edge (90º) Headwall Inlet Depression: None 22

23 Table 6 - Downstream Channel Rating Curve (Crossing: Prop Culvert-1) Flow (cfs) Water Surface Elev (ft) Depth (ft) Velocity (ft/s) Shear (psf) Froude Number Tailwater Channel Data - Prop Culvert-1 Tailwater Channel Option: Irregular Channel Channel Slope: User Defined Channel Cross-Section: Coord No. Station (ft) Elevation (ft) Manning's n Roadway Data for Crossing: Prop Culvert-1 Roadway Profile Shape: Irregular Roadway Shape (coordinates) 23

24 Irregular Roadway Cross-Section: Coord No. Station (ft) Elevation (ft) Roadway Surface: Paved Roadway Top Width: ft 24

25 Crossing Front View (Roadway Profile): Prop Culvert-1 25

26 Table 7 - Summary of Culvert Flows at Crossing: Prop Culvert-2 Headwater Elevation (ft) Total Discharge (cfs) Prop-No increse in HW Elev Discharge (cfs) Roadway Discharge (cfs) Iterations Overtopping 26

27 Rating Curve Plot for Crossing: Prop Culvert-2 27

28 Table 8 - Culvert Summary Table: Prop-No increse in HW Elev Total Discharge (cfs) Culvert Discharge (cfs) Headwater Elevation (ft) Inlet Control Depth (ft) Outlet Control Depth (ft) Flow Type Normal Depth (ft) Critical Depth (ft) Outlet Depth (ft) Tailwater Depth (ft) Outlet Velocity (ft/s) Tailwater Velocity (ft/s) * 0-NF * 1-S2n * 1-S2n * 1-S2n * 1-S2n * 1-S2n * 5-S2n * 5-S2n * 5-S2n S2n S2n

29 * theoretical depth is impractical. Depth reported is corrected. ******************************************************************************** Inlet Elevation (invert): ft, Outlet Elevation (invert): ft Culvert Length: ft, Culvert Slope: ******************************************************************************** 29

30 Culvert Performance Curve Plot: Prop-No increse in HW Elev 30

31 Water Surface Profile Plot for Culvert: Prop-No increse in HW Elev Site Data - Prop-No increse in HW Elev Site Data Option: Culvert Invert Data Inlet Station: ft Inlet Elevation: ft Outlet Station: ft Outlet Elevation: ft Number of Barrels: 3 Culvert Data Summary - Prop-No increse in HW Elev Barrel Shape: Concrete Box Barrel Span: 9.00 ft Barrel Rise: 6.00 ft Barrel Material: Concrete Embedment: 0.00 in Barrel Manning's n: Inlet Type: Conventional Inlet Edge Condition: Square Edge (90º) Headwall Inlet Depression: None 31

32 Table 9 - Downstream Channel Rating Curve (Crossing: Prop Culvert-2) Flow (cfs) Water Surface Elev (ft) Depth (ft) Velocity (ft/s) Shear (psf) Froude Number Tailwater Channel Data - Prop Culvert-2 Tailwater Channel Option: Irregular Channel Channel Slope: User Defined Channel Cross-Section: Coord No. Station (ft) Elevation (ft) Manning's n Roadway Data for Crossing: Prop Culvert-2 Roadway Profile Shape: Irregular Roadway Shape (coordinates) 32

33 Irregular Roadway Cross-Section: Coord No. Station (ft) Elevation (ft) Roadway Surface: Paved Roadway Top Width: ft 33

34 Crossing Front View (Roadway Profile): Prop Culvert-2 34

35 Table 10 - Summary of Culvert Flows at Crossing: Prop Culvert-3 Headwater Elevation (ft) Total Discharge (cfs) Prop- HW Elev 1.5' Below Shoulder Discharge (cfs) Roadway Discharge (cfs) Iterations Overtopping 35

36 Rating Curve Plot for Crossing: Prop Culvert-3 36

37 Table 11 - Culvert Summary Table: Prop- HW Elev 1.5' Below Shoulder Total Discharge (cfs) Culvert Discharge (cfs) Headwater Elevation (ft) Inlet Control Depth (ft) Outlet Control Depth (ft) Flow Type Normal Depth (ft) Critical Depth (ft) Outlet Depth (ft) Tailwater Depth (ft) Outlet Velocity (ft/s) Tailwater Velocity (ft/s) * 0-NF * 1-S2n * 1-S2n * 1-S2n * 1-S2n * 1-S2n * 1-S2n * 1-S2n * 5-S2n S2n S2n

38 * theoretical depth is impractical. Depth reported is corrected. ******************************************************************************** Inlet Elevation (invert): ft, Outlet Elevation (invert): ft Culvert Length: ft, Culvert Slope: ******************************************************************************** 38

39 Culvert Performance Curve Plot: Prop- HW Elev 1.5' Below Shoulder 39

40 Water Surface Profile Plot for Culvert: Prop- HW Elev 1.5' Below Shoulder Site Data - Prop- HW Elev 1.5' Below Shoulder Site Data Option: Culvert Invert Data Inlet Station: ft Inlet Elevation: ft Outlet Station: ft Outlet Elevation: ft Number of Barrels: 3 Culvert Data Summary - Prop- HW Elev 1.5' Below Shoulder Barrel Shape: Concrete Box Barrel Span: ft Barrel Rise: 6.00 ft Barrel Material: Concrete Embedment: 0.00 in Barrel Manning's n: Inlet Type: Conventional Inlet Edge Condition: Square Edge (90º) Headwall Inlet Depression: None 40

41 Table 12 - Downstream Channel Rating Curve (Crossing: Prop Culvert-3) Flow (cfs) Water Surface Elev (ft) Depth (ft) Velocity (ft/s) Shear (psf) Froude Number Tailwater Channel Data - Prop Culvert-3 Tailwater Channel Option: Irregular Channel Channel Slope: User Defined Channel Cross-Section: Coord No. Station (ft) Elevation (ft) Manning's n Roadway Data for Crossing: Prop Culvert-3 Roadway Profile Shape: Irregular Roadway Shape (coordinates) 41

42 Irregular Roadway Cross-Section: Coord No. Station (ft) Elevation (ft) Roadway Surface: Paved Roadway Top Width: ft 42

43 Crossing Front View (Roadway Profile): Prop Culvert-3 43

44 7.0 PHOTOS 44

45 Upstream of Culvert 45

46 Upstream of Culvert 46

47 Downstream of Culvert 47

48 Downstream of Culvert 48

49 Downstream of Culvert 49

50 Parapet Wall 50

51 Parapet Wall 51

52 52

53 53