seafarer’s center pedestrian bridge_presentation

SEAFARER’S CENTER PEDESTRIAN BRIDGEPRESENTATION7/28/2016

OBJECTIVE Introduce the Seafarer’s Center

Pedestrian Bridge Project and review the project process and results.

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

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

OPTIMAL ROUTES

Option 1: Located 112 feet from the bottom of the ditchOption 2: Located 300 feet from the bottom of the ditchOption 3: Located 230 feet from the bottom of the ditch

NARROW DOWN ROUTES

SCALE 1 bad2 medium3 good

Remaining Options:Option 1Option 2

OPTION 1

OPTION 2

AERIAL PHOTO

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

PAINTED STEELAdvantages DisadvantagesHigh strength to weight Weak fire resistance

Strong and flexible Maintenance: Must be repaintedEco-friendly and low waste  Brittle fractureUniformity  Susceptibility to bucklingDuctility a solid material's ability to deform

under tensile stress FatigueToughness the ability of a material to absorb

energy and plastically deform without fracturing Heavy and expensive to transport

ALUMINUMAdvantages Disadvantages

Light weightLow bendingLow vibration absorption

Low stress capability

Anti-corrosiveHigh strength to weight ratio  Conductivity  Resilient  Recyclable  Seamless  

GALVANIZED STEEL

Galvanized steel is steel that has been coated with zinc to prevent corrosion.

Advantages Disadvantages

Long life Internal rusting

Low corrosion Unstable jointsProtection at all areas Water contamination

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 environmentso Weathering steel should not be

used for bridges within 2km of coastal water.

Appearance improves with age

Atmospheric PollutionWeathering steel should not be used in atmospheres where high concentrations of corrosive chemicals or industrial fumes, specifically SO2, are present.

Long Term Performance  

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 Bridge60' by 6' cost $35,100 28' by 6' cost $17,700

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 1 bad2 medium3 good

ALUMINUM VERSUS STEEL LIFE CYCLE COST

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.

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.

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

DECK MATERIAL RECOMMENDATION Maintenance, durability, adherence (non-slip surface), and

sustainability should be considered when choosing the most suitable decking material.

Decking Material MatrixMaintenance

Durability

Adherence

Sustainability Cost SUM

Aluminum deck 3 3 3 3 3 15Standard Timber Tech Composite Decking 1 1 1 2 2 7

FRP Synthetic Concrete 2 2 2 1 1 8SCALE 1 bad

2 medium3 good

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

LOADINGS

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

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

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.

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

ANCHORBOLT

BRIDGE AND FOUNDATION DRAWINGS

LOCATION

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

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

SEAFARER’S CENTER

PHASE 2

PHASE 1

Objective:Introduce the Seafarer’s Center Pedestrian Bridge Project and review the project process and results. Objective met? Any questions?