Sand Relocation Project

Transcription

1 Sand Relocation Project (Contract E ) Dade County BEC & HP Project Tom R. Martin, P.E. Senior Coastal Engineer USACE, Jacksonville District February 15, 2013 US Army Corps of Engineers JACKSONVILLE DISTRICT

2 Dade County Beach Erosion Control & Hurricane Protection Project ( Dade BEC&HP )

3 BUILDING STRONG

4 BUILDING STRONG

5 Before & After Fed Project Initial Fill = 15.1 Mcy / Renourishment = 3.3 Mcy

6 Erosion Continues

7 BUILDING STRONG

8 Hotspot!

9 Hotspot! Accretionary Zone

10 BUILDING STRONG

11 Most frequent area of renourishment (9)

12 Northern erosive area 32 nd St Breakwaters Southern erosive area

13 Miami Beach - Erosional Hotspots February 2009

14 South Beach Accretionary Zone

15 BUILDING STRONG

16 All Dade offshore BA s are exhausted. Future borrow options include : Cleaning out existing offshore BA s Upland sources Offshore BA s outside of Dade County Nondomestic sources Relocation of material from existing beaches

17 Basic Backpassing Strategy

18 Previous Backpassing Operations : Truck Haul Operations in 1996, 2002 Larger-scale pumping operations in 2007, 2012.

19 Backpassing Considerations Environmental Impacts (at borrow and fill areas) RSM / Downdrift Impacts Disruption (tourism, concessionaires, surrounding hotels and businesses) Public Safety Noise, vibration, pollution, aesthetics Opposition at the borrow site Low production rate vs erosion Truck-haul : Unconsolidated fill vs hydraulic placement

20 Pumping vs Trucking : Pro s & Cons Pumping is more efficient for moving large volumes Less traffic : environmental, safety, aesthetic concerns Slurry fill compacts better; better performance Less (?) equipment required Higher mob/demob costs Pump/Pipes can be maintenance intensive Pipeline can limit backpass distance

21 Challenging Construction Zone

22 Challenging Politics

23 Challenging Politics Original Design

24 Challenging Politics Final Design Original Design

25 (16 th St.)

26 Basic Layout of Contract E Backpassing Operation N. Fill R53-R54 S. Fill R60-R61 Borrow R64-R69

27 Contract E Sand Backpass Operation Total volume of 84,000 cy backpassed Length of fill areas = 2,100 feet Length of borrow area = 5,000 feet Pumping distances of 1.1 and 2.3 miles Fill area : 205-ft construction template Borrow area : 100-ft cut into seaward berm Methodology : Pipeline transport of slurry

28 Overall Project Layout

29 Overall Project Layout Borrow zone

30 Overall Project Layout Slurry Pump Borrow zone

31 Overall Project Layout Pipeline Pipeline Slurry Pump Borrow zone

32 Overall Project Layout Discharge / Earthmoving equipment Pipeline Pipeline Slurry Pump Borrow zone

33 Overall Project Layout Discharge / Earthmoving equipment Pipeline Pipeline Slurry Pump Borrow zone

34 Equipment / Setup

35 Overall Layout

36 Overall Layout

37 Overall Layout 100

38 Overall Layout

39 Overall Layout

40 Overall Layout

41 Overall Layout

42 Overall Layout

43 Excavation at the Borrow Site

44 Stockpiling Borrow Material

45 Safety Zone Around Loader

46 Pump and Hydraulic Loader

47 Loading the Hopper

48 Discharge Pipeline

49 Booster Pump

50 Slurry Discharge

51 Discharge / Fill Area

52 Discharge / Fill Area

53 Final Placement and Shaping

54 Finished Project

55 B/A -C

56 BUILDING STRONG

57 Lessons Learned Backpassing can be a viable method if : Downdrift effects are not important Distance between borrow and fill areas not too great Disruptions to beach use/operations not too great Requires special attention to : Public/political aspects : noise, disruption, safety, etc. Tradeoffs between trucking and pumping

58 Questions?