2 Pedestrian Bridge Master Report

Empirical Design Solutions Team 7

Structural Master Report (Pedestrian Bridge) Chandler Municipal Airport Expansion Author: Matthew Smith

November 21, 2014

Empirical Design Solutions Structural Master Report (Pedestrian Bridge)

Table of Contents 1. Executive Summary…………………………………………………………………………………………………………….. 2. Introduction…………………………………………………………………………………………………………………………5 2.1. Purpose……………………………………………………………………………………………………………………..….5 2.2. Project Location…………………………………………………………………………………………………………….5 2.3. Discussion of Project……………………………………………………………………………………………….......6 3. Site Specifications….…………………………………………………………………………………………………………….8 3.1. Soil……………………………………………………………………………………………………………………………….. 8 3.2. Drainage………………………………………………………………………………………………………………………. 8 3.3. Flooding ………………………………………………………………………………………………………………………. .8 3.4. Utilities…………………………………………………………………………………………………………………………. 8 4. Pedestrian Bridge Designs……………………………………………………………………………………………………9 4.1. Concrete AASHTO AASHTO I-Beam Type II Bridge Preliminary Design…………………………………………9 4.2. Concrete AASHTO Box Beam BIII-48 Bridge Prel iminary Design………………………………….. 4.3. Pedestrian Bridge Specifications………………………………………………………………………………… 4.4. Retaining wall/Abutments……………………………………………………………………………………….... 4.5. Ramps………………………………………………………………………………………………………………………..5 4.6. Aesthetics…………………………………………………………………………………………………………………. .15 5. Construction ………………………………………………………………………………………………………………………5 6. Costs…………………………………………………………………………………………………………………………………. 16 7. Bridge Selection………………………………………………………………………………………………………………… 18 8. Sustainability………………………………………………………………………………………….………………………….8 9. References…………………………………………………………………………………………………………………………9

List of Figures Figure 2-1: Project Location…………………………… .…………………………………………………………………………5 Figure 2-: Land Use Bubble Plan….……………………………………………………………………………………………6 Figure 2-3: Bridge Location on Lake ……. .……………………………………………………………………………………7 Figure 4-1: AASHTO I Beam type II Profile Profi le View.…………………………………………………………………………9 Figure 4-2: AASHTO Box Beam type BIII- 8…..……………………………………………………………………………9 Figure 4-3: Plan View I Beam…. .………….…………..………………………………………………………………………. 10 Figure 4-4: I Beam Dimensions.………….………… ..………………………………………………………………………. Figure 4-5: I Beam Properties……….…………………………………………………………………………………… .……10 Figure 4-6: I Beam Strand Chart………………………… ..………………………………………………………………….. Figure 4-7: AASHTO Box Beam type BIII-48 Profile View………………………………………………………….. Figure 4-8: AASHTO Box Beam type BIII-48 Cross Section.……..……………………………………………….. Figure 4-9: Plan View Box Beam...………………………………………….………………………………………………..3 Figure 4-10: Box Beam Properties ………………………………………… .………………………………………………..3 Figure 4-: Box Beam Strand Chart………………………………………………………………………………………..3

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List of Tables Table 4-: AASHTO I Beam type II Specifications……..……………………………………………………………… .13 Table 4-2: AASHTO Box Beam type BIII-48 Specifications..…….…………………………………………………3 Table 4-3: AASHTO I Beam type II Cost Breakdown.………………….…………………………………………….. 6 Table 4-4: AASHTO Box Beam type BIII-8 Cost Breakdown…………………………… .…………………….…7

Appendices Appendix 1: Concrete AASHTO Box beam calculations ……………………………………………………………. Appendix 2: Concrete AASHTO I beam calculations …………………………………………………………………. Appendix 3: Abutment Calculations………………………………………………………………………………………… Appendix 4: Project Validation Form………………………………………………………………………………………..

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1. Executive Summary The Chandler Municipal Airport Expansion will be constructed on the northwest corner of Gilbert Rd and Queen Creek Rd. It will take place on 422 acres of land with zoning spanning from commercial, residential, parks and recreation, all the way to multiple airport zonings. Most of the land being development is in agricultural zoning, so rezoning these areas will be easier because the land is already flat which makes construction faster and cheaper. The airport will incur an additional runway to accommodate a higher volume of planes landing and taking off. This increase in volume is due to the addition of the aviation school and residential parcels that include personal hangers. A taxi-way will be added to the south eastern portion of the airport for the pilots that own a house in the residential area. This taxi-way will be limited to residential owners only. The taxi-way will lead to the front of all the homes. Driveways will then part off from the taxi-way and lead to hangers in the resident’s lot . On the northern portion of the development an aviation school will be added to help anyone pursuing a pilot’s

license and also students learning about aviation. The majority of the zoning along the two arterial roads surrounding the corner of Gilbert Rd and Queen Creek Rd are going to be commercial because they generate the highest volume of traffic and need the easiest access. On the southern portion of the land development there will be a park built with a large pond that flows under Cooper Rd and also flows under a pedestrian bridge. The pedestrian bridge has been designed to be 52 feet long and 8 feet wide spanning the width of the pond. Two alternative designs have been presented in detail further in this report. The first design consists of two type II AASHTO I beams supporting the decking of the bridge. The second design consists of two 4ft wide type BIII-48 AASHTO box beams. Both designs will have a concrete slab above the beams but will have different thickness. Both designs will also have steel handrails and solar panels as the top decking. These solar panels are called Type 2 Prototype solar panels that are considered the future of solar power. They are designed to replace asphalt concrete in a pavement design so they will be more than strong enough to withstand pedestrian and OHV(off highway vehicle) loading. The solar panels will produce enough power to run all electrical services on the park grounds. After considering both bridge designs, the I beam bridge has bee n chosen to be the more reasonable option. It was chosen based off of price, aesthetics, and functionality. The box beam bridge uses a higher volume a concrete which causes higher loading on the foundation and also a higher cost in concrete. The pedestrian bridge will be considered a monument of the park in future years to come.

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2. Introduction 2.1 Purpose Included in the Chandler Municipal Airport Expansion will be a pedestrian bridge that gives pedestrians access from one side of the park in parcel 3 to the other side. The bridge will be running north and south and its main purpose is to get people over the pond/lake in the park area. It will also be built to withstand OHV (off highway vehicles) travel that is used for park maintenance if needed. It will be designed according to AASHTO standards with pre-cast beams. 2.2 Project Location The proposed airport expansion will take place at Chandler Municipal Airport which is located at the northwest corner of Gilbert road and Queen Creek road in Chandler, AZ. The Loop 202 Santan Freeway is a half mile north and the 87 highway (Arizona Ave) is just over a mile west of the project. Figure 2-1: Project Location

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2.3 Discussion of Project The project will be executed on the northeast corner of Queen Creek Rd and Gilbert Rd next to the already existing Chandler Municipal Airport as previously discussed. The new land proposed to be developed contains 12 new zones that range from commercial all the way to park and recreation. There are no major washes flowing through this site. The majority of proposed zoning along the major arterials is commercial seeing that it needs the easiest access and generates the largest traffic volume of all the zones. A residential area in parcel 6 as seen below in figure has been created for pilots that want to land their planes and then pull their plane into their own hanger instead of the airport hangers. This residential area will contain homes that can be used daily or as vacation homes depending on the owner. They will have direct access to the runway through parcel 5 that serves as a taxi-way. Figure 2-2: Land Use Bubble Plan

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Just south of the residential area is an area zoned for a park that will contain a pond/lake with a 52’ pedes trian bridge spanning across it as seen in figure just below. Figure 2-3: Bridge Location across Lake

The bridge will be made from either concrete type II AASHTO I beams or from concrete BIII-48 AASHTO box beams. Abutments will be constructed on each end of the bridge to provide a foundation and support for the beams to be placed on. Each end of the bridge will have a concrete ramp for access to the bridge. The pond will be about 5 ft below the top of the bridge depending on how much rain has fallen. The bridge will be covered in Phase II Prototype solar panels that will provide power to park features such as lighting and water features in the park to be as sustainable as possible. The bridge will be aesthetically pleasing and be considered a park monument for years to come.

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3. Site Specifications 3.1. Soil The predominant soil found in Chandler is a gravel with some stiff clay with an average unit weight of 115 lb/ft^3. Clay is an expansive soil but the percentage of clay compared to gravel in the area isn’t high enough to be factored in into the

bridge design. This soil is considered strong enough to withstand the bearing pressure of the pedestrian bridge. 3.2. Drainage All water that falls onto the bridge from rain will runoff into the pond below. The small amount of rain water that hits the ramps on each end will also drain the rain water out into the park grass. 3.3. Flooding Flooding will not be a major issue in regards to the pedestrian bridge. The bridge will be high enough above the surface of the water that heavy rains will not overflow onto the bridge. The overflow will go out into the park grass. The pond will not be used for a retention. The only water that can enter the pond is from direct rain fall into the water. The park will be flat so that rainwater will leach into the ground where it lands, this way the pond will not overflow from heavy rains. 3.4. Utilities The bridge is located in the middle of the park therefore there will not be many existing utilities except for possible irrigation lines. The whole site will be blue-staked and all existing utilities will be accounted for. For proposed utilities there will be electrical lines that run to and from the solar panels and future lighting being placed in the park. There will also be electrical lines installed that can run to the future possible water fountain in the pond. A small version of the Bellagio fountains may look nice as far as aesthetics which could run off of power from the output of the solar panels.

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4. Pedestrian Bridge Designs 4.1 Concrete AASHTO I-Beam Type II The I beam bridge was the first of the two bridges to be designed and calculated. All dead loads, live loads, and wind loads were calculated using AASHTO guidelines. Detailed calculations can be found in Appendix A. The live load for pedestrians came out to be 1.187 kip/ft and 1 kip/ft for OHV. The dead load came out to be 1.02 kip/ft. The beam may seem a bit over built in regards to a pedestrian bridge but it is not only limited to pedestrians. The bridge has been designed to also withstand loads from OHV (off highway vehicles) such as rhinos, gators, rzrs, rangers, and any sort of buggy that the landscapers and parks and rec. workers may use. The horse shoe shaped pond covers a large portion of the park and access is needed over the water to minimize haul time. Figure 4-1: AASHTO I Beam type II Profile View

Figure 4-2: AASHTO I Beam type II Cross Section

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Figure 4-3 shows a profile view of the bridge in the park. The water can be seen in blue and grass can be seen around the bridge ramps in green. The solar panels are located atop of the bridge in a box/textile format. A small gap of soil can be seen between the pond water and grass to show the level that the water will be at the majority of time depending on rainfall. Figure 4-3: Profile View I Beam

Below a detailed figure of the dimensions of the AASHTO I Beam type II are shown. Figure 4-4: I Beam Dimensions

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Figure 4-5 shows more detailed information about the I beams properties and dimensions. Figure 4-5: I Beam Properties

The Type II beam was chosen because it has a max span length of 55 ft. The pedestrian bridge being built is 52 feet long which made it a great fit. The Type I beam had a max span length of 40 feet which made it too small for this project. The Type III beam was taken into consideration but because of its larger area it would be considered over built. The factor of safety would have been too safe on the Type III beam making it too expensive for this project. Figure 4-6 shows a detailed chart on how to determine the amount of reinforcing steel needed in the beam. The spacing of the I beams was predetermined to be 6 feet and the span to be 52 feet long. By using both of these numbers it can be seen on the chart that the I beam will need 13 strands per beam. The concrete will need to be 7000 psi as shown circled in lower right hand corner of the chart.

Figure 4-6: I Beam Strand Chart

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4.2 Concrete AASHTO Box Beam BIII-48 The box beam bridge was the second bridge designed and calculated. All dead loads, live loads, and wind loads were calculated using AASHTO guidelines. Detailed calculations can be found in Appendix B. The live load came out to be .335 kip/ft for pedestrians and 1k/ft for OHV. The dead load came out to be 1.187 k/ft. This beam may also seem a bit over built in regards to a pedestrian bridge but it is not only limited to pedestrians. The bridge has been designed to also withstand loads from OHV (off highway vehicles) such as rhinos, gators, rzrs, rangers, and any sort of buggy that the landscapers and parks and recreation workers may use. The horse shoe shaped pond covers a large portion of the park and access may be needed over the water to minimize haul time if necessary.

Figure 4-7: AASHTO Box Beam type BIII-48 Profile

Figure 4-8: AASHTO Box Beam type BIII-48 Cross Section

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Figure 4-9 shows a plan view of the bridge in the park. The water can be seen in blue and grass can be seen around the bridge ramps in green. The solar panels are located atop of the bridge in a box/textile format. A small gap of soil can be seen between the pond water and grass to show the level that the water will be at the majority of time depending on rainfall. Figure 4-9: I Profile View Box Beam

Figure 4-10 shows more detailed information about the box beam properties and dimensions.

Figure 4-10: Box Beam Properties

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Figure 4-11 shows a detailed chart on how to determine the amount of reinforcing steel per box girder like in Figure 4-6 for the I beam. Using an 8 foot wide bridge at 52 feet long gives a strand count of 17. The strand locations inside the box beams can be find in the cross section of the bridge of the bridge in figure 4-8 above.

Figure 4-11: Box Beam Strand Chart

4.3 Pedestrian Bridge Specifications Both of the tables below have shown all specifications and totals needed to complete each beam. Table 4-1: AASHTO I Beam type II Specifications Description

Specification

Dimensions

Total per item

Excavation Labor Foundation I Beams Reinforcing Steel Concrete Slab Railing Solar Panels

remove/compact assembly 7000 PSI 7000 PSI 15,000 lbs 4000 PSI steal

CYD HRS CYD 52' long .5"diamx52' 8'x4"x73'5" 3"diameter 2'x2'x4"

6CYD 112HRS 4.59CYD 4.93CYD 676 ft 7.24CYD 128LF 4SQFT

Quantity

2 5 2 2 2 1 2 78

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Table 4-2: AASHTO Box Beam type BIII-48 Specifications Description

Specification

Dimensions

Total per item

Quantity

Excavation Labor Foundation Box Beams Reinforcing Steel Concrete Slab Railing Solar Panels

remove/compact assembly 7000 PSI 7000 PSI

CYD HRS CYD 52' long

6CYD 112HRS 4.59CYD 10.87CYD

2 5 2 2

15,000 lbs 4000 PSI

.5"diamx52' 8'x4"x73'5" 3"diameter 2'x2'x4"

676 ft 7.24CYD 128LF 4SQFT

2 1 2 78

4.4 Abutments There will be a 2ft 10in retaining wall on top of a 1ft thick foundation on each end of the bridge holding the soil pressure back. The retaining walls have been designed to hold the soil pressure back but they will also have water from the pond loading the insides of the walls. The retaining wall/abutment will be a monolific pour and is 3ft 10in deep. These structures will hold the live and dead loading of the bridge. These structures have been designed to meet all specs necessary and provide efficient safety and will hold all forces being loaded on them. 4.5 Ramps On both ends of the bridge ramps will be constructed for access to the brid ge. These ramps will be wheel chair accessible at an angle of 21 degrees from horizontal. These ramps will also allow OHV traffic to access the bridge. The ramp s will be constructed from compacted dirt covered with a 4in slab of 4000 psi concrete. 4.6 Aesthetics The final bridge will not be painted but will actually be a bit rustic looking to the eye. As seen around the valley some buildings have steel as their outer surface and when rained on it gives off a rustic type of look. This type of aesthetic will be used on the bridge outer surface and handrails. A thin metal sheeting will be placed on the outer visible sides of the bridge.

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5. Construction The construction of this project will be as efficient as possible to keep costs under the GMP of the project. The soil taken from the pond will be used to build the ramps at each end of the pedestrian bridge. The excess soil taken from the pond will be used to create a slope like surrounding in some parts of the park. Some soil can also be used to build some of the nearby building pads if it meets spec. First the foundations and retaining wall areas will be dug and compacted to meet spec. The abutment will then be poured mono-lifically. The precast beams will then be placed on top of the abutments by a large crane and bolted down to their anchor bolts. The ramps will then be backfilled with soil and then compacted. The upper slab will then be poured on top of the beams and for the ramps. Next, the railing will be installed and bolted down to the slab. Lastly the solar panels will be installed and all aesthetic related portions will be executed to leave a well-constructed and beautifully designed bridge.

6. Costs The following tables will give a cost breakdown of the two different concrete bridges being designed. Table 4-3: AASHTO I Beam type II Cost Breakdown Description

Specification

Dimensions

Total per item

Excavation Labor Foundation I Beams Reinforcing Steel




$20/CYD $17/hr $300CYD $300/CYD

2 5 2 2

$240 $9,520 $2,755 $2,958

15,000 lbs imperial flat sheet 4000 PSI steel Type 2

.5"diamx52'

676 ft

$0.95/LF

2

$1,284.00

SQFT 8'x4"x73'5" 3"diameter 2'x2'x4"

200SQFT 7.24CYD 128LF 4SQFT

$1.66/SQFT $90/CYD $9/LF $135/panel

2 1 2 78

$666.66 $652.44 $2,304 $10,530 $30,910.10

metal sheeting Concrete Slab Railing Solar Panels Total Contingencies (15%) Total

Unit Cost

Quantity Total Cost

15% $35,546.62


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Table 4-4: AASHTO Box Beam type BIII-48 Cost Breakdown Description

Specification

Dimensions

Total per item

Excavation Labor Foundation Box Beams Reinforcing Steel metal sheeting Concrete Slab Railing Solar Panels Total




$20/CYD $17/hr $300CYD $300/CYD

2 5 2 2

$240 $9,520 $2,755 $6,522

15,000 lbs imperial flat sheet

.5"diamx52'

676 ft

$0.95/LF

2

$1,284.00

SQFT

200SQFT

$1.66/SQFT

2

$666.66

4000 PSI steel Type 2

8'x4"x73'5" 3"diameter 2'x2'x4"

7.24CYD 128LF 4SQFT

$90/CYD $9/LF $135/panel

1 2 78

$652.44 $2,304 $10,530 $34,474.10

Contingencies (15%) Total

Unit Cost

Quantity

Total Cost

15% $39,645.22

Both bridges have similar prices because they are made from a lot of the same materials. The main differences of the two bridges are the difference in the beams used and the size of the concrete slabs used for the decking. In the I beam bridge it was chosen to use a thicker 6” concrete slab because the I beams won’t give as much support in the center of the bridge because it will be overhanging the water. Where as in the box beam bridge it will have a 3” concrete slab because it already has deck support from the 5.5” thick upper portion of the beam that spans across the

whole width of the bridge. The largest costs to the bridges were the labor costs and the cost of the solar panels. Labor was determined by estimating it would take 5 labors at 8 hours a day for 2 weeks to complete the bridge. The solar panels seem like a large cost, but with most solar investments, they will pay themselves off and then save money in the long run. They are also a needed sustainability factor for the project.


7. Bridge Selection After taking both designs into consideration, a decision has been made to forward with the I beam bridge for multiple reasons. The most important reason for choosing the I beam bridge is based off of cost of materials. A lot the materials on both bridges are the same but the largest difference is the type of beams used. The I beam uses a little less than half of the concrete that the box beam uses. This excess use of concrete with the box beam will be about $4,000 more expensive than the I beam bridge. The extra 5cyd of concrete will also result in a higher dead load that ultimately will affect the foundation in a negative way. The I beam is cheaper, more functional, and more aesthetically pleasing and that is why it has been chosen as the beam of choice for this project.

8. Sustainability One of the main goals of the Chandler Municipal Airport Expansion is to develop and construct the property to be as sustainable as possible. In pre-job meetings it will be a main focus point. All contractors will try their best to not waste any materials in the building process and try to be as efficient as possible when using large equipment to avoid excess greenhouse gases. For the pedestrian bridge, instead of having a top decking of steel or a concrete slab it will have type II prototype solar panels. These solar panels are in the process of being patented by their inventing company but will be ready for use by the time of construction of the project. These solar panels are strong enough to withstand the weight and loading of large vehicles. They are designed to replace asphalt paving on roadways but will be used at a walkway in this case. There will be OHV (of highway vehicle) loading from groundskeepers and landscapers for the park that need to get from one side of the pond to the other. This type of loading will be no problem for the solar panels as they are rated for heavier vehicles. The cutting edge solar panels will feed power to the surrounding lighting of the bridge and park but also to the water feature/fountain in the underlying pond. The initial cost of these solar panels will be $10,530 but they will pay themselves off in the near future by providing power to the entire park and recreational area. The final choice of designing a concrete bridge was mainly decided by cost but also for sustainability reasons. Concrete has a long lifespan that can go over 100 years in some cases. Concrete needs less maintenance than the alternative of steel.

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9. References http://www.solarroadways.com http://www.fhwa.dot.gov/everydaycounts/technology/bridges/pbeswebinartraining/s3_m7.cf m http://www.oceansteel.com/aashtotech.aspx http://www.solarhome.org/solartech40wsolarpanel.aspx?gclid=CIbGwfyHq8ECFeZAMgodGywA QQ http://www.virginiadot.org/business/resources/pc-box-beams-12.pdf http://www.lowes.com/Hardware/Structural-Hardware/Sheet-Metal

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Appendix 1: Concrete AASHTO Box Beam calculations

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Appendix 2: Concrete AASHTO I Beam calculations

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Appendix 3: Abutment Calculations

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Appendix 4: Project Validation Form

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2 Pedestrian Bridge Master Report

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