Transcript Bridge Protection System - Mechanical Engineering at the

Current Delaware Memorial
Bridge Protection System
Bridge Protection System
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Team: 98.6
Members: Nikhil Bhate, Brandon Clark, Neil Smith, Scott
Suhmann
Direct Customer: Hardcore DuPont Composites, LLC
Advisor: Dr. Jack Vinson
Mission: By the end of Spring Semester 1998, design, fabricate,
and test a working unit section model of a bridge protection
system that gives meaningful information towards replacing
the current fender system on the Delaware Memorial Bridge.
Approach: Use Total Quality Design principles to provide a
background for concept generation and evaluation.
Customers List:
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Hardcore DuPont:
• George Tunis, Dave Harris
Delaware River Bay Authority (DRBA):
• Joe Volk, Rick Volk, Steve Moore
Delaware Pilot’s Association:
• Captain Linton
Army Corps Of Engineers:
Governmental Agencies:
Construction Crew:
Other Ships and Vessels:
• Maurice Richard, Tony Smith
Wants, Metrics, and Target Values
Prioritized Wants
No damage to bridge.
Associated Metrics
Deflection
Energy
Percent Hardcore
Composite
Target Values
<20 ft
6.24x107 ft-lbs.
10%-100% by
volume
Easy to install
Construction Time
Elastic
Yield Strength
Easy to maintain
Maintenance time
1 Construction
Season: 6
months
75000 psi in
composite
8000 psi in
concrete
< 1 week per
year
Use composites
Wants, Metrics, and Target Values
Prioritized Wants
Associated Metrics Target Values
Profitable
Cost
< $30 million
Quick to replace
Repair Time
< 6 months
damaged components
Easily dockable
System Height
Level with
footing
Minimal ship damage Hull Deformation
Wide passage
System Width
Aesthetically pleasing Appearance
< 325' from
base
Conventional
looking,
available in
different colors
Constraints:
 Cannot Alter Bridge Foundation
 Cannot Obstruct 1000 foot channel
 Visible
 No Creosols
 No Lead Based Paints
Benchmarking
 System Benchmarking
• Protection Systems for smaller vessels
– Camels, Fenders, Springs
• Protection Systems for larger vessels
– Sunshine Skyway Bridge, Golden Gate Bridge, Great
Belt Easter Bridge
Benchmarking
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Functional
Benchmarking
• Energy Absorbing
Systems
– Hex-Foam, Cushion
Wall, Hexalite, Fluidic
Shocks
Hex-Foam Sandwich
Cushion Wall
Concept Generation
 Artificial Island
 Stand Alone Dolphin System
 Horizontal Piling Structure
 Pile Supported Fender with Large Protective
Cells
Artificial Island
Large island
surrounding footing,
made of any material
 Easy to Construct
 Difficult to apply
composites
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Dolphin System
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Two or more composite
walled structures filled
with crushed stone or
sea shells around
footing
Prevents head-on
impact
Too expensive to
protect side impact
Horizontal Piling Structure
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Filled Pilings arranged
horizontally outward from
footing.
Device attached to induce
fracture inside piling on
impact
Dissipates energy
through fracture
mechanics
Theory difficult to apply to
ship impact
Destroyed during use
Pile Supported Fender with
Protective Cells
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Takes advantage of large
protective cells for head
on impact
Channel side protected by
smaller fender structure
Uses composites to aid
installation
Makes use of structural
aspects of composite
materials
Complex design
Concept Selection
 Evaluated advantages and shortcomings of
concepts through an iterative design
process (SSD).
 Pile Supported Fender System determined
to be the best in terms of satisfying wants
and metrics
Advantages of Design
 Uses composites to reduce installation
time
 Composite adds structural advantages
• Composite replaces rebar by taking tensile
loads
• Composite confines concrete eliminating the
need for stirrups in support column
Concept Discussion
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Choosing a design vessel:
Channel Traffic Over 3 Years
3000
Number of Ships
2500
2000
1500
1000
500
0
0
200
400
600
800
1000
Tonnage of Ships (x 100)
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An 80,000 ton ship was chosen
1200
1400
1600
Concept Discussion
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Vessel Speed and
Orientation:
• Using tactical
diameter, depth
conditions, and
current flow data an
angle of attack of 30°,
and speed of 4 knots
was calculated.
Design Details
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Protective Cells:
• 80 ft dia.
• Situated at footing end
to prevent head on
collision
• Composite sheath,
filled with gravel, and
capped with concrete
Design Details
 Support Columns
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12 ft dia.
1” thick carbon glass hybrid pile
Installed in sections
Filled with concrete
Assumed to be cantilevered at 500 year scour
Design Details
 Support Column
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Applied load: 1.11E6 lbs.
EI total: 2.17E13 lb.-in^2
Base Bending Moment: 1.07E9 in-lb.
Tube tensile stress: 5.37E4 psi
Filler compression stress: 7.4E3 psi
Design Details
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Fender
• 20 ft. x 15 ft. x 36 ft.
• Concrete encased with
‘bottle core’ composite
• Cone at base for
installation
• Rebar used to
distribute load to pile
Design Methodology
Energy vs. Velocity
Energy (ft-lbs)
3.00E+08
2.50E+08
2.00E+08
1.50E+08
1.00E+08
5.00E+07
0.00E+00
0
2
4
6
Velocity (knots)
8
10
Design Methodology
 Design focus on support column and fender
• Protective cell size benchmarked
 Iterative design process for support
column
• analyzed diameters of 10 ft. to 14 ft.
• determined the flexural rigidity of composite
column with concrete filler
Force - Displacement
Testing
 Tested to determine distribution factor
to the adjacent piles.
Force vs Diplacement
Displacement (in/1000)
250
200
y = 115.42x - 8.9752
One Pile
150
Eleven Piles
Linear (Eleven Piles)
100
Linear (One Pile)
50
DF=9.33
y = 12.371x - 2.5591
0
0
0.5
1
1.5
Force (lbs.)
2
2.5
due
Costing
 Concrete: $875,000
 Composites:
• Protection Cell -- $400,000
• Support Columns -- $165,000
• Bottle Core Wall -- $3,750,00
 Total:
$10.3 million
 Labor: $9.5 million
Issues for Further Investigation
 Further costing analysis
 Connecting fender to end protection cells
 Test a larger scale prototype for further
proof of distribution factor.