2. OBJECTIVE
Introduce the Seafarer’s Center Pedestrian
Bridge Project and review the project
process and results.
3. WHY BUILD A PEDESTRIAN BRIDGE?
The seafarer’s center will have a restaurant open
soon and POHA employees will need a way to cross
the ditch to reach the Seafarer’s center
It will provide access to a safe haven during fire drills
It will provide recreation through a jogging trail
(coming up next year)
It would provide support to not just executive building
inhabitants, but also parking for those who attend
large Seafarer’s Center Events
4. AGENDA
Optimal Routes
Bridge Design Considerations
Painted Steel
Aluminum
Galvanized Steel
Weathered Steel
Bridge Fabrication and Erection Cost Estimates
Bridge Material Recommendation
Aluminum vs Steel Life Cycle Cost
Recommended Material
Deck Material Recommendation
Loadings
Option Recommendation
Foundation Design
Anchorbolt Design
Bridge and Foundation Drawings
5. OPTIMAL ROUTES
Option 1: Located 112 feet from the bottom of the ditch
Option 2: Located 300 feet from the bottom of the ditch
Option 3: Located 230 feet from the bottom of the ditch
10. BRIDGE DESIGN CONSIDERATIONS
Design consideration factors:
Loading: Pedestrian Traffic
Must not run into cable installed in the ground
Width:
The ADA compliant minimum inside clear width is 4 feet,
but the actual width of the bridge will be 5 to 6 feet
Narrow Bridge Advantages
more efficient load support
less material
minimizes the risk of unintended use (like vehicular traffic)
Since a narrow bridge is advantageous, we will go with
the minimum:
6 feet
Potential length of bridge:
Option 1: 60 feet
Option 2: 28 feet
11.
12. PAINTED STEEL
Advantages Disadvantages
High strength to weight Weak fire resistance
Strong and flexible Maintenance: Must be repainted
Eco-friendly and low waste Brittle fracture
Uniformity Susceptibility to buckling
Ductility
a solid material's ability to deform under
tensile stress Fatigue
Toughness
the ability of a material to absorb energy and
plastically deform without fracturing Heavy and expensive to transport
14. GALVANIZED STEEL
Galvanized steel is steel that has been
coated with zinc to prevent corrosion.
Advantages Disadvantages
Long life Internal rusting
Low corrosion Unstable joints
Protection at all areas Water contamination
15. WEATHERING STEEL
"Weathering" refers to the chemical
composition of these steels, allowing them to
exhibit increased resistance to atmospheric
corrosion compared to other steels.
Advantages Disadvantages
Low maintenance
Marine environments
o Weathering steel should not be used for
bridges within 2km of coastal water.
Appearance improves with age
Atmospheric Pollution
Weathering steel should not be used in
atmospheres where high concentrations of
corrosive chemicals or industrial fumes,
specifically SO2, are present.
Long Term Performance
16. DESIGN BUILD COST ESTIMATES
Painted Steel Excel Bridge
60' by 6' cost $53,000
28' by 6' cost $32,000
Aluminum deck Gator Bridge
60' by 6' cost $33,450
28' by 6' cost $18,000
Excel Bridge
Galvanized Steel 60' by 6' cost $68,000
28' by 6' cost $42,000
Weathered Steel Big R Bridge
60' by 6' cost $35,100
28' by 6' cost $17,700
17. BRIDGE MATERIAL RECOMMENDATION
Weathering steel is ruled out because:
It should not be used in atmospheres where high concentrations of corrosive chemicals or
industrial fumes are present
It is within 2 K of coastal waters
This leaves the options of:
Painted Steel
Aluminum
Galvanized Steel
Materials
Matrix Strength
Eco-
friendly Flexible
Anti-
corrosive
Fire
Resistance Maintenance
Ease of
Transport Weight Cost SUM
Painted Steel 2 1 1 1 1 1 2 9
Aluminum 1 2 1 2 2 3 2 2 3 18
Galvanized
Steel 3 1 3 1 2 1 1 1 13
SCALE
19. Figure 1 shows the Present Value (PV) for
each cost and Total Cost of Ownership (TCO)
for each option for a three percent discount
rate. Using a three percent discount rate,
aluminum has a better TCO than all other steel
options by more than $7,000 for an urban
environment, and by more than $16,000 for a
maritime environment. Aluminum has a TCO
equivalent to galvanized steel after 33 years in
the urban environment, and after 21 years in
the maritime environment.
20. RECOMMENDED MATERIAL
The recommended material to be
used for the bridge is aluminum.
Cost:
The material cost itself is the least
It has the least total cost of ownership
Materials Matrix
It scored the highest amount of point in the
materials matrix, due to advantageous factors
that outweighed those of the other materials.
21. DECKING MATERIAL
Decking Options:
Aluminum
Standard Timber Tech Composite Decking
Fiber Reinforced Polymer Synthetic Concrete
*Prices below include bridge and deck
Aluminum deck Gator Bridge
60' by 6' cost $33,450
28' by 6' cost $18,000
Standard Timber Tech Composite Decking Gator Bridge
60' by 6' cost $36,150
28' by 6' cost $19,260
FRP Synthetic Concrete Gator Bridge
60' by 6' cost $36,870
28' by 6' cost $19,596
22. DECK MATERIAL RECOMMENDATION
Maintenance, durability, adherence (non-slip surface),
and sustainability should be considered when choosing
the most suitable decking material.
Decking Material Matrix Maintenance Durability Adherence Sustainability Cost SUM
Aluminum deck 3 3 3 3 3 15
Standard Timber Tech Composite
Decking 1 1 1 2 2 7
FRP Synthetic Concrete 2 2 2 1 1 8
SCALE
23. RECOMMENDED DECKING MATERIAL
The recommended decking material is aluminum
Least cost
Most points in the decking material matrix
Durable, slip resistant, remains cool to the touch
27. OPTION RECOMMENDATION
Maximum allowed load according to Geotechnical report:
4500 psf
Load the drill shafts of the 60 foot bridge would have to
resist:
5000 psf
Recommended cause of action:
Have geotechnical engineer drill 50 feet, obtain bore hole, and
provide allowable skin friction resistance or other method to
resist 5000 psf
Use the 28 foot bridge option
28. DECISION:
To use the 28 foot option
Less project cost due to the size being half of
the 60 foot
Cost of geotechnical engineer drilling bore
holes saved
29. FOUNDATION DESIGN
Foundation Design Program Viathor Vbent
Analysis run on the estimated dimensions to
predict whether it can sustain the maximum
loading or not.
Hand calculations done to confirm the
Foundation Design Program results as well.
30. FOUNDATION DESIGN
Pier Diameter
2.5 feet
Pier Length
22-24 feet
Because, as seen in the Bore Log Report above,
the soil obtains stiffness at 24 feet
10 inch Backwall
Abuntment Cap
2 feet deep
3 feet wide
10 feet long
38. RESULT:
Bridge:
aluminum bridge and deck
Lighting will be added upon completion
28 foot bridge, 6 foot clear width
Foundation:
Piers, backwall, abutment cap, anchorbolts designed
Bid Package:
CAD Drawings:
Abutment, bridge location and details, foundation, profile, silt fence, dam
Specifications:
Bridge
Drilled Pier
Excavation
Hydromulching
Safety
Mobilization and demobilization
Storm water control
39. SCHEDULE
Advertise on Buyspeed: November 10th, 2016
Bid Proposal Due Date: December 14th, 2016
Prebid Meeting/Site Visit: November 10th, 2016
Seafarer’s Center Restaurant Opening:
January/February
