Underwater Concrete Technologies in Marine Construction Projects

Transcription

1 Underwater Concrete Technologies in Marine Construction Projects Sam X. Yao Ben C. Gerwick, Inc.

2 oncrete Production from a Floating Batch Plan

3 Conventional Tremie Placement

4 Concrete Delivery on Transit Mixers

5 Placing Concrete from a Delivery Barge

6 Tremie Placement with Suspended Pipes

7 Underwater Concrete Construction Technologies Concrete Mix Proportions Workability and Rheology Strength Development Underwater Concrete Construction Concrete Placement Planning Concrete Production/Transportatio Mass Tremie Concrete Properties Thermal Behavior Form Pressure Concrete Placement Procedures Finish and Protection Inspection and Quality Control Laitance, Bleeding, Segregation

8 erformance Requirements for Underwate Concrete in Structural Applications Flowability and Self-Compaction Workability Retention within Work Window Cohesion Against Washout, Segregation, and Laitance Formation Low Bleeding Low Heat of Hydration Controlled Set Time Compressive Strength Adequate Bond

9 Washout Test and Slump Test

10 Slump vs. Slump Flow

11 Mock-up Tremie Concrete Test

12 Mock-up Tremie Concrete Test

13 Principal Parameters in Mix Design Particle Packing Characteristics - Sand Content, Gradation, Size, and Shape The water-to-fine ratio - Enough Fine to Make It Flowable and Cohesive ( by volume) Cementittious Material Content High Volume Fly Ash plus Silica Fume Dispersion characteristics - Proper Use of Chemical Admixtures HRWR and Set-retarder

14 Tremie Concrete Placement Planning An Overview llowable Work Window llowable Flow Distance acement Area Configuration Concrete Production & Delivery: Method & Rate Concrete Placement Sequence Tremie Placement Rate & Procedure Form Pressure ISK FACTORS rodcution & Delivery ogistics oss of Flowability ashout - Laitance egregation, Bleeding rapping of Water xcessive Disturbance rosion Tremie Pipe Layout Form Design Slope, Vent, Laitance Collector Quality control plan: Testing, sounding, inspection Concrete Protection Concrete Flow Pattern Quality of In-Situ Concrete Strength Uniformity Bond

15 Initiation of Tremie Placement Initiation of Placement using the Dry Pipe Method with a End Plate as the Seal

16 c * h + Ww * D + F W c R Hydrostatic Balance Point H = (W c h+w w D+F R ) / W c

17 Flow Patterns of Tremie Copncrete Layered Flow - Excessive Laitance Bulging Flow - Minimum Laitance

18 Tremie Pipe Spacing 3-5 Times Depth of Tremie Pours

19 Placement Sequence Simultaneous Placement Method Advanced Slope Method

20 Removal of Laitance Underwater

21 Lower Monumental Dam

22 Hydraulic Flow Pattern in Stilling Basin

23 Pomona Dam Stilling Basin Hydraulic Model Study

24 18 months after repair Kinzua Stilling Basin

25 Erosion Damage

26 Erosion Damage Repair

27 Erosion Repair within a Cofferdam

28 Undrewater Repair of a Dam

29 Tremie Concrete over Rock Anchor

30 Coarse Aggregates pecific Gravity: 2.85 bsorption: 1.1% aximum Nominal ize: 3/4-inch ppearance: Clean nd round-shaped ith smooth surface xture

31 Fine Aggregates Specific Gravity: 2.72 Fineness Modulus: 2.9 Absorption: 3.0% Natural River Sand

32 Gradations of Aggregates Volume Ratio of Fine Aggregates to Total Aggregates: 47% Volume Ratio of Coarse Aggregates to Total Solids: 42% Percentage Passing Sand Grading Curve Combined Sand and Gravel Gravel 0 #200 #100 #50 #30 #16 #8 #4 3/8" 1/2" 3/4" 1" 1-1/2" Sieve Number

33 igh Volume Fly Ash Concrete for Underwater Repa Reducting the heat of hydration in mass concrete Increasing concrete flowability without compromising cohesion Facilitating concrete flowability retention and extended set time

34 Mix Proportions Mix No. 1 Mix No. 2 Mix No. 3 (52% F.A) (25% F.A) (control) ement Type II, lb./cy ly Ash, lb./cy icro Silica, lb./cy oarse Agg, lb./cy ,659 1,688 ine Agg, lb./cy 1,367 1,396 1,420 ater, lb./cy heomac UW, oz/cwt elvo, oz/cwt lenium, oz/cy

35 Compressive Strength Development Averag e Comp ressive Streng th (p si) Mix 3 Mix 2 Mix Age (days)

36 itial Concrete Slump 10 to 10-3/4 itial Slump Flow 21 to 26 inimum Requirement r Achieving 1:10 lope on Top Surface f the Concrete Pours 10 Slump and 20 lump Flow Workability Test

37 Workability Retention Test lump after 60 minutes 10 to 10-3/4 lump flow after 60 min. 21 to 26 nticipated work indow for a truck of oncrete 45 minutes

38 Set Time Test Mix No. 1 Set Time > 12 hour Mix No. 2 and No. 3 Set Time = 7 hour Anticipated Concrete Placement Duration: 12 hours

39 remie Concrete Placement at the Dam Sit

40 Tremie Concrete Placement Sequence

41 Tremie Concrete Slump

42 Tremie Concrete Placement

43 Concrete Cores

44 Conventional Dam Construction

45 Cofferdam Failure

46 Conventional Lock Construction

47 Cofferdam Overtopping

48 Cleanup After the Flood

49 Braddock Dam

50 Braddock Dam - Illustration Towing and Positioning In Dam.ppt

51 Braddock Grouting -In Dam.ppt

52 Braddock Dam Stage 5 Concrete Infill -In Dam.ppt

53 27.5 River Miles from Fabrication Site to Outfitting Pier Leetsdale (Fabrication Site) 3 Miles N Ohio River Emsworth L/D ashields L/D Mile 13.3 Pittsburgh Mile 14.7 Mile 6.2 Allegheny River Braddock L/D Mile 0.0 Duquesne RIDC (Outfitting Pier) Mile 11.2 Monongahela River Mile 12.8

54 In-the-Wet Foundation Preparation

55 Underwater Foundations PILE DRIVING BARGE FLOW SCREED BARGE Concurrent Operations: Dredge/Backfill Place Base Stone Screed Stone Install Piers

56 Fabrication Site Launch Basin Segment 1 Segment 2

57 Braddock Dam

58 Top Slab Fabrication

59 Segment 1 in Launch Basin

60 Transport of Dam Segment 1

61 Towing and Setting a Float-in Dam

62 Braddock Dam

63 Savings: 1 Year 5 Million Braddock Dam

64 Construction Complete

65 Florida Keys

66 Coral Reef in Florida Keys

67 One of the Ground Sites

68 Damaged Coral Reef

69 Repair Design

70 Precast Repair Module

71 Repair of Corral Reef in Florida Keys

72 Setting a Precast Module

73 Floating Batch Plants

74 Adding Nitrogen Cooling Agent

75 Repair of Coral Reef in Florida Keys Pumping Concrete Underwater

76 Placing Underwater Concrete

77 lacing Concrete in Large Holes of Corral

78 Finishing Underwater Concrete

79 Project Location

80 Coachella Canal Engineering Data Construction period Length 123 mi Diversion capacity 2,500 cfs Typical section, earth lined: Bottom width ft Side slopes 2:1 Water depth 10.3 ft Lining, clay-blanket 12 in Typical section, concrete lined: Bottom width 12 ft Side slopes 1.5 :1 Water depth 10.8 ft Lining thickness 3.5 in

81 Salton Sea/Coachella Canal One of numerous geothermal plants on the eastern side of the Salton Sea. Bombay Beach at Salton Sea. The Coachella Canal. Coachella Canal Bathers.

82 Installation of Liner and Concrete Overlay Kiewit received a $5.2 Million Contract to Install 1.5 miles test section at Coachella Canal. Paving half of a section at a time Average Speed: 4-ft per minute

83 Canal Lining Design

84 Liner: 30 mil thick PVC geomembrane backed with a nonwoven geotextile Nonwoven fabric prevent slippage of concrete during placement and strengthen the liner Vibrator on slip form to consolidate and maintain concrete flow Trial Testing

85 Completion of the Lining Construction