2009 final report team 14

Team 14:

Going Green

Engineering 340

Calvin College

5/19/2009

Final Design Report

Mike Vander Ploeg

Michael Dirkse

Jeff Bergman

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Table of Contents

1. Executive Summary ............................................................................................................................................... 5

2. Introduction ........................................................................................................................................................... 8

a. Team Members ................................................................................................................................................ 8

b. Project Background .......................................................................................................................................... 8

3. Objectives .............................................................................................................................................................. 8

a. Project Objectives ............................................................................................................................................. 8

b. Design Norms ................................................................................................................................................... 9

i. Stewardship................................................................................................................................................ 10

ii. Transparency .............................................................................................................................................. 10

iii. Integrity ...................................................................................................................................................... 11

4. Green Roof Benefits............................................................................................................................................. 11

a. Educational Benefits ....................................................................................................................................... 12

5. Green Roof Design ............................................................................................................................................... 12

6. Hydraulic Design .................................................................................................................................................. 13

a. Introduction .................................................................................................................................................... 13

b. Precipitation and Temperature Data .............................................................................................................. 14

c. Snow Melt....................................................................................................................................................... 14

d. Evapotranspiration ......................................................................................................................................... 15

e. Drainage and Runoff ....................................................................................................................................... 16

f. Irrigation System ............................................................................................................................................ 16

i. Alternatives ................................................................................................................................................ 16

ii. Soil Moisture .............................................................................................................................................. 17

iii. Timed Irrigation .......................................................................................................................................... 18

iv. System Type ............................................................................................................................................... 18

v. System Layout ............................................................................................................................................ 19

g. Cistern Sizing .................................................................................................................................................. 21

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h. Pump Operation ............................................................................................................................................. 24

i. Pump Sizing .................................................................................................................................................... 24

j. Pipe Selection and Sizing ................................................................................................................................ 26

k. Stormwater Collection and Conveyance ........................................................................................................ 28

l. Optional Gravel Filtration Bed ........................................................................................................................ 29

7. Structural Design ................................................................................................................................................. 29

a. Entry Structure ............................................................................................................................................... 33

8. Cost Analysis ........................................................................................................................................................ 33

a. Hydraulic System ............................................................................................................................................ 33

b. Green Roof and Structural supports ............................................................................................................... 34

c. Total cost ........................................................................................................................................................ 35

9. Conclusion ........................................................................................................................................................... 36

10. Further Steps .................................................................................................................................................. 36

11. Acknowledgements ........................................................................................................................................ 36

12. Bibliography .................................................................................................................................................... 37

Table of Figures

Figure 1: New Commons Building .................................................................................................................................. 5

Figure 2: Green Roof Stormwater Management Process Diagram ............................................................................... 6

Figure 3: Green Roof Layers ........................................................................................................................................ 13

Figure 4: Green Roof Stormwater Management Process Diagram ............................................................................. 14

Figure 5: Soil moisture range chart.............................................................................................................................. 17

Figure 6: Plan View of Irrigation Layout ...................................................................................................................... 20

Figure 7: Water Level Over Time in a 22,000 Gallon Cistern ....................................................................................... 23

Figure 8: Plan view of storage cisterns ........................................................................................................................ 23

Figure 9: Plan View of Drainage System ...................................................................................................................... 26

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Figure 10: Footing layout for the green roof design .................................................................................................... 32

Table of Tables

Table 1: Evapotranspiration Calculations for the Wet Year (1986) ............................................................................. 16

Table 2: Irrigation system comparison ........................................................................................................................ 19

Table 3: Sprinkler Head Radius and Area Covered ...................................................................................................... 20

Table 4: Irrigation Zone Design .................................................................................................................................... 21

Table 5: Water Flows for a 22,000 Gallon Cistern ....................................................................................................... 22

Table 6: Total Headlosses for Each Irrigation Zone ..................................................................................................... 25

Table 7: Peak Flow Rates for Downspouts................................................................................................................... 27

Table 8: Downspout and Collection Pipe Diameters ................................................................................................... 28

Table 9: Point Load Capacities for Plastic Grate .......................................................................................................... 29

Table 10: Design roof loads for the green roof and a standard roof design................................................................ 30

Table 11: Floor loads applied to model ....................................................................................................................... 31

Table 12: Cost Analysis for Hydraulic System Components......................................................................................... 34

Table 13: Cost of green roof and structural supports .................................................................................................. 35

Appendices

Appendix A: Green Roof Soil Specifications................................................................................................................. 38

Appendix B: Drainage Layer Specifications .................................................................................................................. 39

Appendix C: Hydraulic Model of Green Roof Stormwater Management and Irrigation System ................................. 40

Appendix D: Snow Melt Calculations ........................................................................................................................... 43

Appendix E: Evapotranspiration Calculations .............................................................................................................. 45

Appendix F: Drainage and Runoff Calculations ........................................................................................................... 48

Appendix G: Irrigation Controller Specifications ......................................................................................................... 49

Appendix H: Comparison of Timed Irrigation to Irrigation Based on Soil Moisture .................................................... 51

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Appendix I: Sprinkler Head Specifications ................................................................................................................... 53

Appendix J: Annual Energy Costs for Pumps ............................................................................................................... 54

Appendix K: Pump Curves and Specifications .............................................................................................................. 55

Appendix L: Minor Head losses Due to Pipe Bends ..................................................................................................... 58

Appendix M: Head losses for Pipes in each Irrigation Zone ........................................................................................ 60

Appendix N: Pump Head Calculations ......................................................................................................................... 61

Appendix O: Peak Flow Rate Calculations for Downspouts ......................................................................................... 62

Appendix P: IDF Curve for Kent County ....................................................................................................................... 63

Appendix Q: Downspout Size Calculations .................................................................................................................. 64

Appendix R: Drainage and Collection Pipe Calculations .............................................................................................. 65

Appendix S: Drainage Channel Size Calculations ......................................................................................................... 67

Appendix T: Beam and Column Check Calculations .................................................................................................... 68

Appendix U: Foundation Design and Calculations ....................................................................................................... 79

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1. Executive Summary

Recent construction projects at Calvin have highlighted the issue of sustainable growth

on campus. In an effort to promote sustainable growth, the team decided to design an

intensive green roof, stormwater management system, and irrigation system for the southern

portion of the new Commons building that is currently being proposed (see Figure 1). Also

included was a comprehensive look at the costs involved in the construction of a green roof.

The resulting design was a green roof that would provide aesthetic as well as environmental

benefits to the entire Calvin community.

Figure 1: New Commons Building

The green roof designed by the team is an intensive roof with a six inch thick layer of soil

with grassy vegetation. In addition to the stormwater runoff reduction the roof would provide,

it was also designed to allow students or other members of the Calvin community to use the

area as a recreational space. This would allow Calvin to get the maximum amount of use out of

the roof.

Proposed Green Roof

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In addition to the green roof itself, the design also includes a stormwater collection and

reuse system which would increase the amount of stormwater retained by the system and

reduce the dependence on outside sources for irrigation. This system collects runoff from the

roof and stores it in underground cisterns. The water in these cisterns is then pumped back to

the roof for irrigation. This allows the green roof to reduce stormwater runoff over 65% in an

average year as compared to a more traditional roofing system. In case of drought, the system

provides emergency inflow from Calvin’s current irrigation system. During a heavy rainfall, the

system provides outflow to the storm sewer system to prevent it from being overwhelmed.

Figure 2 shows a process diagram of the system.

Figure 2: Green Roof Stormwater Management Process Diagram

As part of the design, it was decided that the structural systems of the new commons

building would need to be modeled in order to accurately determine the total cost of the green

roof. The southern half of the building, which included the green roof, was modeled. This

included the entire portion of the roof that would support the extra load of the green roof.

From this model, beam, column, and foundation sizes were calculated for a traditional metal

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roof and the green roof. Comparing the extra support required for the green roof to the

standard roof allowed a good estimation of the additional costs for the green roof.

The total cost for the irrigation system was estimated at $41,000. This includes the

cisterns, pumps, sprinkler heads, and all required piping. The extra cost for the green roof

compared to a metal roof came out as estimated at $350,000. The total cost of the green roof is

around $700,000 or $32 per square foot. The entire green roof project would total less than

2.8% of the budget for the entire $25 million commons renovation project.

In order to pursue this project, it is recommended that Calvin begin talking local

engineering firms with experience in green roof design and construction. With their help,

Calvin can further refine the green roof design and move to a construction phase.

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2. Introduction

a. Team Members

Team 14 consists of three senior civil/environmental engineering students: Jeff

Bergman, Michael Dirkse, and Mike Vander Ploeg. After graduation, Jeff Bergman plans to

attend University of Michigan and pursue a master’s degree in structural engineering. Michael

Dirkse plans to serve with Engineering Ministries International in India for a month after

graduation. While in India, he will be a part of a team of architects and engineers who will work

on a design project involving improvements to the structures and water systems of a hospital

and a school. Michael plans to pursue work in water resources and/or environmental

engineering in the future. Mike Vander Ploeg is currently looking for full-time employment in

the areas of water resources, geotechnical, or transportation engineering.

b. Project Background

The project started with the idea of designing a water recycling system (“toilet to tap”

system) for Calvin’s campus. After considering this idea, the scope of the project was expanded

to include any improvements to Calvin’s water systems. The three water systems considered

were: wastewater, drinking water, and stormwater. The team explored the feasibility of four

different alternatives for improving these systems: a water recycling system (“toilet to tap”

system), a greywater re-use system, a stormwater re-use system for irrigation, and green roofs.

After conducting a feasibility study, the team found that the water recycling system, the

greywater re-use system, and the stormwater re-use system would not be feasible if

implemented on Calvin’s campus. However, the team discovered that it would be feasible to

construct a green roof on a new building on Calvin’s campus to improve the stormwater

system. The team decided to design an intensive green roof on the southern section of the new

Commons building.

3. Objectives

a. Project Objectives

The project was split into two areas – structural and hydraulic design. The objective of

the structural design was to determine how much extra steel would be needed to support the

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additional loads of a green roof compared to a conventional roof. To achieve this goal, the

team sought to model the beams and columns for the portion of the new Commons building

that would support the green roof. The objective of the hydraulic portion of the project was to

design a stormwater recycling and irrigation system which would provide adequate irrigation to

the vegetation on the green roof and provide a significant reduction in stormwater runoff when

compared to the runoff from a traditional roof of the same size. The team sought to optimally

size different components of the hydraulic system such as storage cisterns, pumps, pipes, and

sprinkler heads. An overall project objective was to complete a cost analysis of both the

hydraulic system and the structural requirements for the construction of a green roof on the

southern portion of the new commons building.

b. Design Norms

Design norms played an important role in this project because they provided ethical and

moral guidelines for the design. In an engineering design process it is critical to not only

evaluate the design from a technical perspective, but also from an ethical and moral

perspective. The way a design fits into the surrounding environment and culture is something

that cannot be overlooked in the design process. It is important to consider the impact that

design decisions will have on the people that will use the system that is being designed.

Three design norms applied specifically to the design of the green roof for the new

Commons building: stewardship, transparency, and integrity. The team sought to incorporate

these design norms into all design decisions. Stewardship in an engineering design accounts for

how well resources are used. Any engineering project will utilize both financial and

environmental resources. These resources should be used efficiently and in ways that preserve

the natural environment. People usually interact with engineered systems every day.

Transparency is a design norm that evaluates how well the users of the designed system

understand the system they interact with. It is critical for the users of the system to know why

the system was designed and what function it performs. Integrity in an engineering design

evaluates how close the appearance of the design is to the actual function of the design. Some

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engineered systems may appear to perform a certain function, but if they do not actually

perform this function adequately, then the design does not show integrity.

i. Stewardship

As a Christian college, Calvin seeks to act as stewards of God’s creation. Stewardship

includes the responsibility to use natural resources and preserve ecosystems in a way that

honors God. With the addition of a green roof, Calvin can more efficiently manage its water

resources and preserve the natural environment. The stormwater recycling system will

significantly reduce the amount stormwater runoff from the roof of the commons building.

Stormwater runoff from the commons building currently flows into the seminary pond. This

stormwater contains fertilizers and other nutrients. When excess amounts of nutrients

accumulate in the seminary pond, this causes significant algae growth. When the growth of

algae becomes excessive, the amount of dissolved oxygen in the seminary pond decreases

significantly. Decreased dissolved oxygen levels are detrimental to aquatic life and disruptive to

the ecosystem of the pond. When stormwater runoff is decreased, it helps to maintain

ecological stability and diversity of species in the seminary pond. In this way, the green roof on

the new commons building would help Calvin fulfill God’s call to be stewards of the earth by

preserving the natural environment.

In addition to acting as God’s stewards of natural resources, Calvin also seeks to use

financial resources wisely. With this in mind, the team designed the green roof, the stormwater

recycling system, and the irrigation system to be low in cost, while still fulfilling their intended

purposes. Financial stewardship in this project was sought by choosing quality, cost effective

components in the design.

ii. Transparency

Transparency was another design norm that was incorporated into the design of the

green roof. It is vital that the Calvin community will be able to understand the purpose of the

green roof and feel comfortable with how the roof looks and operates. The green roof would

provide educational opportunities, which will help students to understand how the green roof

works and the benefits it provides to Calvin and the surrounding environment. The green roof

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can act as a teaching tool to inform students about water quality issues associated with

stormwater runoff and aquatic life.

iii. Integrity

Integrity is the third design norm that was incorporated into the design of the green

roof. It is critical that the green roof and the structure supporting it be designed to adequately

fulfill their intended purposes. The Calvin community should be assured that the green roof

and its supporting structure will not fail. When storing a lot of water on a roof, leaking is a big

concern. It is important that the Calvin community also feels confident that this will not occur.

Calvin’s students, faculty, and staff should have the assurance that the stormwater recycling

system and the irrigation system will operate correctly and efficiently.

4. Green Roof Benefits

There are many benefits associated with a green roof. The primary benefit associated

with green roofs is the amount of water they are able to retain. Thus, stormwater runoff and

its associated pollution and negative effects on pond ecosystems would be reduced. A further

benefit of a green roof is a decrease in heating and cooling costs for the building. Layers of soil

and plant matter provide extra insulation in the winter, and in the summer evapotranspiration

acts to cool the roof. A green roof could also supply extra green space for recreational use by

the Calvin community.

Constructing a building on Calvin’s campus with a green roof would provide a positive

image for the college. In recent years, building projects at Calvin have required the removal of

a number of trees from the campus. This was a move that has been strongly opposed by

students as well as donors and faculty members. For example, the building of the Spoelhof

Fieldhouse Complex required the removal of a large wooded area. This was a controversial

move among the Calvin community. The situation has been further exacerbated by the fact

that Calvin’s administration has not sought LEED certification for many of its new projects. The

addition of a green roof to the new Commons building would be a major step in repairing these

relationships and well worth the moderate investment it would require. In addition, green

roofs are perceived by many people as a sign of environmental stewardship. Calvin would

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further build its reputation as a college that is committed to conserving natural resources if a

green roof was constructed on the new commons building.

a. Educational Benefits

A green roof can provide many opportunities for advancement in education. A green

roof can provide the Calvin community with a working example of what a green roof is.

Another educational benefit could be for students to plant gardens with different types of

plants on the roof. Planting different gardens would not only improve the aesthetic value of

the roof but also allow students to take ownership of the roof and discover what types of plants

would thrive on green roofs. Another educational benefit of the roof would be the study of the

efficiency of the green roof. Students could measure the amount of runoff from the green roof

and compare it to a standard roof. This would show the community the value a green roof has

in stormwater reduction. Studies could also be done to analyze the quality of the recycled

stormwater that is used for irrigation on the green roof. Engineering students could design

ways to improve the quality of the stormwater, such as implementing a gravel bed for filtration.

5. Green Roof Design

A 22,000 square foot intensive green roof was designed for the southern portion of the

new Commons building. The roof was designed to serve as a recreational area for the students,

faculty and staff at Calvin College. Several types of plants could be grown on the green roof,

but designing specific components the landscape of architecture of the green roof was beyond

the scope of this project. For simplification purposes, the team assumed that the green roof

would be covered entirely with grass. Below the grass, there will be a 6 inch layer of Rooflite

intensive green roof soil, which is specifically designed for applications on intensive green roofs

(see Appendix A for specifications). Underneath the soil there will be a drainage layer, which

will act to convey water away from the green roof. This drainage layer consists of a polystyrene

core (7/16 inch thick), which is enclosed by two layers of polypropylene geotextile fabric (see

Appendix B for specifications) giving the layer a total thickness of approximately 1 inch. The

additional layers of the green roof are shown in Figure 3.

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Figure 3: Green Roof Layers

6. Hydraulic Design

a. Introduction

The team approached the hydraulic design of the irrigation and stormwater

management system as a water balance problem. There are several process streams in this

system, including: rainfall, evapotranspiration, runoff from the green roof to the cisterns, water

pumped from the cisterns to the green roof, inflow from Calvin’s irrigation system to the

cisterns, and emergency outflow from the cisterns to the storm sewer. Daily flows of water

within these process streams were quantified and analyzed in an Excel spreadsheet (Appendix

C). This spreadsheet acted as a tool to size different components of the system. A process

schematic diagram of the system is shown in Figure 4.

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Figure 4: Green Roof Stormwater Management Process Diagram

b. Precipitation and Temperature Data

Daily precipitation and temperature data for Grand Rapids, MI, from the last 50 years was

analyzed. This data was obtained from:

http://dipper.nws.noaa.gov/hdsb/data/archived/index.html. From this data, total precipitation

within each year was calculated and a wet year (highest annual rainfall), a dry year (lowest

annual rainfall), and an average year (average annual rainfall) were determined and

incorporated into the model. These years were chosen to provide an accurate representation

of rainfall in Grand Rapids, while reducing the total amount of data within the model. In

addition to precipitation data, the minimum, maximum, and average temperatures for each day

were recorded in the spreadsheet.

c. Snow Melt

Daily precipitation data in the model was quantified as either a rainfall volume or a

snowfall volume. If the temperature on a given day was below freezing, a snowfall volume

would be calculated by multiplying the precipitation amount by the green roof area. In a similar

way, the precipitation would be quantified as rainfall if the temperature was equal to or above

http://dipper.nws.noaa.gov/hdsb/data/archived/index.html

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the freezing point. All snowfall volumes in the model are expressed as water-equivalent

volumes. The distinction between snow and rain was made in the model because spring snow

melts can cause a significant amount of runoff, which would directly affect the cistern level and

amount of discharge to the storm sewers.

Snow accumulation was quantified on a daily basis by adding the snow volume from the

previous day to the snowfall from the current day and then subtracting snow melt. A water-

equivalent snow melt volume for each day the year was calculated if there was any snow

accumulation on the roof (See Appendix D). The daily snow melt volumes were then

incorporated into calculating daily volumes of runoff from the green roof into the cisterns.

Including snow melt in the model increased the accuracy of the runoff calculations.

d. Evapotranspiration

Evapotranspiration is very difficult to accurately calculate because it depends on several

parameters that are highly variable and hard to quantify with readily available information.

These parameters include: wind speed, solar radiation, exposed water surface area, and

humidity. However, approximate estimates for evapotranspiration can be made using readily

available information such as air temperature. The Thornthwaite-Mather method was used to

make the evapotranspiration calculations for the green roof (See Appendix E).

Table 1 shows the evapotranspiration calculations for the wet year (1986).

Evapotranspiration data for the other two years was calculated in a similar way (See Appendix

E). The value for PET was multiplied by the area of the green roof to obtain the daily volume of

water that exited the green roof through evapotranspiration. This volume of water was

subsequently used to calculate the volume of water that was in the soil on any given day (See

Appendix F).

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Table 1: Evapotranspiration Calculations for the Wet Year (1986)

Wet Year 1986 Total Days Avg. Temp I /mo PET Adjusted PET PET PET

C

mm/mo mm/mo in/mo in/day

Jan 31 -5.16 0.00 0.00 0.00 0.00 0.0000

Feb 29 -5.32 0.00 0.00 0.00 0.00 0.0000

Mar 31 2.62 0.38 9.46 9.34 0.37 0.0119

Apr 30 9.81 2.75 43.09 47.91 1.89 0.0629

May 31 14.87 5.13 69.37 84.88 3.34 0.1078

Jun 30 18.01 6.84 86.43 110.86 4.36 0.1455

Jul 31 22.52 9.56 111.68 140.67 5.54 0.1787

Aug 31 18.87 7.33 91.19 106.49 4.19 0.1352

Sep 30 17.12 6.34 81.56 85.31 3.36 0.1120

Oct 31 10.09 2.87 44.48 40.97 1.61 0.0520

Nov 30 1.64 0.19 5.53 4.48 0.18 0.0059

Dec 31 -1.22 0.00 0.00 0.00 0.00 0.0000

I= 41.37

a= 1.15

e. Drainage and Runoff

The amount of drainage and runoff from the green roof was another water volume

stream that was quantified in the water balance analysis (Appendix C). If the daily volume of

water in the soil exceeded the saturated soil volume, the difference between the daily volume

of water in the soil and the saturated soil volume was quantified as runoff from the green roof.

If the average temperature was below freezing, no runoff from the green roof was assumed.

f. Irrigation System

i. Alternatives

The team considered two irrigating options for the green roof: irrigation based on soil

moisture and irrigation based on a timed schedule. Irrigating based on soil moisture was found

to be much more efficient because less water was required. Some irrigation at Calvin is already

being done based on evapotranspiration data and soil moisture monitoring. This method of

irrigation will become more prevalent in the future. Irrigating the Commons building green

roof using soil moisture and evapotranspiration data would be advantageous because the staff

at the physical plant would already be familiar with this method of irrigation.

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ii. Soil Moisture

Significant water savings can be achieved when the green roof is irrigated based on soil

moisture. The team recommends that a WaterTec S100 soil moisture probe be installed on the

green roof to carefully monitor the amount of water in the soil so that irrigation can occur only

when the soil is in need of water. This probe will communicate electronically with a Toro TMC-

424-OD Modular irrigation controller (see Appendix G for specifications). Figure 5 was used to

evaluate soil moisture levels and determine when irrigation should occur.

Figure 5: Soil moisture range chart

Source: ftp://ftp.dynamax.com/turf_irrigation/Soil%20Moisture%20Range%20Chart.pdf

Figure 5 was also used to calculate the wilt point volume. If the volume of water in the soil falls

below the wilt point, the grass will begin to die. Adequate irrigation was defined by ensuring

ftp://ftp.dynamax.com/turf_irrigation/Soil Moisture Range Chart.pdf

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that zero days within the three year period in the model had a soil water level that fell below

the wilt point. The team assumed a sandy clay loam soil. For this type of soil, irrigation should

begin when 28% of the volume of the soil is water. This “irrigation start volume” was calculated

in the model and was then compared to the water volume in the soil for each day (see

Appendix A). If the volume of water in the soil for a given day was less than the “irrigation start

volume” and no precipitation occurred for that day, irrigation would occur.

iii. Timed Irrigation

Another option for irrigation was irrigating based on rainfall, average temperature, and

irrigation on previous days. Eight different combinations of these conditions were analyzed

(See Appendix H). Based on these conditions, the amount of irrigation water that would need

to be pumped to ensure that the soil moisture level did not fall below the wilt point was

compared to the amount of water that would need to be pumped if irrigation based on soil

moisture was used instead. A total cistern volume of 47,000 gallons was used in this analysis.

The optimum condition under a timed schedule had the following criteria: irrigation would

occur when the average temperature was greater than 63 °F and no precipitation would fall

that day. Even under this condition, 1.77 times more water would have to be pumped over the

three year period in the model, when compared to irrigation based on soil moisture.

iv. System Type

The team considered two different types of irrigation for use on the green roof: drip

irrigation and conventional irrigation. The team consulted Charles Huizinga and Geoff Van

Berkel from Calvin’s physical plant, as well as Bruce Funnel from Spartan Distributors Inc. for

guidance in deciding between these two options. They recommended using a conventional

irrigation system rather than a drip irrigation system. After considering their advice and the

advantages and disadvantages of both drip and conventional irrigation, the team decided to

implement a conventional irrigation system on the commons building green roof. Table 2

summarizes the advantages and disadvantages of each system.

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Table 2: Irrigation system comparison

Drip Irrigation Conventional Irrigation

Advantages Disadvantages Advantages Disadvantages

- Significant water savings - 90% efficient water use - Lower pressure required (smaller pump) - Easy to water plants with different water requirements

- High cost - More lateral piping required - Difficult to establish root zones (through seeding or by sod) - Inconsistent watering pattern - Susceptible to damage - High maintenance

-Less lateral piping required -Easy to establish root zones -Low maintenance -Lower cost -More proven and familiar irrigation method

-70% efficient water use -Water blows off roof on a windy day -Larger pump required

v. System Layout

Spartan Distributors Inc. assisted the team with designing a layout for different

sprinklers on the green roof. The sprinkler heads were split up into 8 different zones consisting

of different sprinkler heads (Appendix I for specifications). The zones were split up so that

there would be minimal variation in the flow rates of each zone. Figure 6 shows a layout of the

irrigation system.

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Figure 6: Plan View of Irrigation Layout

The area of green roof that each sprinkler zone would cover was calculated using the

pressure at each sprinkler head and the corresponding radius of spray (Appendix I). The

pressures at each sprinkler head were found using the program EPANET, which models water

distribution piping systems. The radius of spray was calculated based on an average pressure of

50 psi for all sprinkler heads. The pressures at each sprinkler head varied from 46.9 - 56.3 psi

according to the EPANET model. Table 3 shows the different radii for each sprinkler head and

the area that it covers.

Table 3: Sprinkler Head Radius and Area Covered

*Radius of spray (ft) Area covered (ft2)

450 R: 3.0 Nozzle 40 2513

450 R: 6.0 Nozzle 46 6648

450 R: 3.0 LA Nozzle 35 3848

*The radius of spray was taken from the 450R Series Pop-up Rotor Specifications (Appendix G)

Zone 6

Zone 1

Zone 8 Zone 3

Zone 5

Zone 4

Zone 7

Zone 2

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The areas in table 3 for each sprinkler head were used to calculate the total area

covered by each irrigation zone. These areas were then used to determine the operating time

for each zone. Operating times per zone were adjusted such that the percentage of area

covered would correspond to the percentage of volume that was pumped by each zone. The

total operating time was adjusted to provide the minimum irrigation volume per day that would

ensure that 0 days were in the wilt zone. These results are summarized in Table 4.

Table 4: Irrigation Zone Design

450 R: 3.0

Nozzle 450 R: 6.0

Nozzle 450 R: 3.0 LA

Nozzle Total Flow Area

Covered

Zone (2.4 gpm) (4.9 gpm) (3.10 gpm) (gpm) (ft2)

1 5 0 0 12 8,796

2 5 0 0 12 10,053

3 1 2 0 12.2 15,808

4 1 2 0 12.2 15,808

5 1 2 0 12.2 15,808

6 0 3 0 14.7 19,943

7 5 0 0 12 11,310

8 4 0 1 12.7 10,132

Totals 22 9 1 100 107,659

% of Total Area Operating Time Volume Pumped % of Volume

Zone Covered per day (min.) (gallons) Pumped

1 8% 14 168 8%

2 9% 16 192 9%

3 15% 25 305 15%

4 15% 25 305 15%

5 15% 25 305 15%

6 19% 26 382.2 19%

7 11% 18 216 10%

8 9% 15 190.5 9%

Totals 100% 164 2063.7 100%

g. Cistern Sizing

The size of the cistern was chosen based on three criteria: providing significant storm

water recycling, minimizing cost, and minimizing inflow from Calvin’s irrigation system. To

appropriately balance these three criteria, a total cistern volume of 22,000 gallons was chosen.

To achieve this total storage volume, four 5,500 gallon precast cisterns will be used. Using four

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precast cisterns from a local supplier (Kerkstra Precast) provided a cheaper option than using a

single fiberglass cistern. The dimensions for the individual cisterns are 15’-8” long x 6’-10”wide

x 10’0”tall with 5” walls. The cisterns will be connected by four 12” pipes to create one larger

cistern. Table 5 shows the amount of water flowing in and out of the cistern and the efficiency

of the system. Figure 7 shows the cistern level for the wet, average, and dry years. Figure 7

shows a layout drawing of the cisterns. Figure 8 shows a plan view drawing of the four cisterns.

Table 5: Water Flows for a 22,000 Gallon Cistern

Rainfall + Snow Melt

(gal.) Irrigation (gal.) Runoff (gal.) Overflow (gal.) Inflow (gal.)

WET YEAR 639,231 18,573 321,122 302,549 0

AVERAGE YEAR 478,095 59,847 198,397 165,378 26,828

DRY YEAR 309,024 179,542 148,005 137,037 156,841

3 YEAR TOTAL 1,426,350 257,963 667,524 604,964 183,669

3 YEAR AVG. 475,450 85,988 222,508 201,655 61,223

23

Figure 7: Water Level Over Time in a 22,000 Gallon Cistern

Figure 8: Plan view of storage cisterns

0

5,000

10,000

15,000

20,000

25,000

0 100 200 300 400 500 600 700 800 900 1000 1100

Tota

l Wat

er

Vo

lum

e in

Cis

tern

s (g

allo

ns)

Number of Days (Wet, Avg., Dry years)

Wet Year

Average Year

Dry Year

Inflow Required

24

The proposed storage cisterns were thought to be beneficial, but not necessary

components of the hydraulic system. The use of storage cisterns will make the green roof more

efficient in recycling stormwater and will reduce demand on the current irrigation system. To

provide adequate pressure at the sprinkler heads on the green roof, a booster pump may be

needed anyway if the cisterns were not included in the design. However, eliminating the

cisterns from the design could provide cost savings. If the cisterns were eliminated, then all

irrigation water would have to be pumped from Calvin’s current irrigation system. For its

irrigation water, Calvin uses irrigation wells rather than potable water from the city of Grand

Rapids. The cost of operating the irrigation pumps would be the only additional cost incurred

by Calvin for extra irrigation. The annual energy cost for operating the irrigation pump and the

cistern pump would be only $9.82 (See Appendix J).

h. Pump Operation

Two identical submersible pumps will be installed in one of the storage cisterns to pump

water to the green roof for irrigation. One pump will be needed for normal operation, and a

second will be installed for redundancy. During each day, one pump will operate for 164

minutes and provide 2,064 gallons of water to the green roof. Flow will switch to 8 different

irrigation zones during this time.

The pumps require 2ft of water to operate. If the water level in the cistern drops below

2ft, a sensor will open an electronic valve which will allow water to flow into the cisterns from

Calvin’s current irrigation system.

i. Pump Sizing

Two Grundfos 16S07-8 (¾ HP) submersible pumps are recommended for the system.

This pump operates within the flow ranges of 10 – 20 gpm (see Appendix K for pump curves

and specifications). This is an acceptable range for all 8 irrigation zones, which vary from 12 -

14.7 gpm (See Table 4). The head losses from pipe friction and minor losses in the pipes from

the pump to the green roof were calculated (See Appendix L) . These values were added to the

minor losses and pipe friction head losses from each zone (See Appendix L and M) to calculate

the total head loss for each zone (see Table 6).

25

Table 6: Total Headlosses for Each Irrigation Zone

From pump to roof In each zone

Zone Minor Losses

(ft) Pipe HL

(ft) Minor Losses (ft) Pipe HL (ft) TOTAL HEADLOSS

(ft)

1 1.12 4.00 0.67 9.83 15.62

2 1.12 4.00 1.57 22.56 29.25

3 1.12 4.00 0.75 10.40 16.27

4 1.12 4.00 0.42 12.57 18.12

5 1.12 4.00 0.80 15.10 21.02

6 1.12 4.00 0.82 5.76 11.71

7 1.12 4.00 1.04 18.06 24.22

8 1.12 4.00 1.49 10.45 17.07

Based on these values, zone two had the highest head loss (29.25 feet). This head loss was

used in the energy equation to calculate the total pump head needed for the pump (See

Appendix N). The total pump head was calculated to be 178.9 feet. The team consulted Eric

Neubecker from Raymer Water Supply Contractors – Wells and Pumps (Marne, MI), requesting

a pump to provide 179 feet of head and a flow rate of 15 gpm. After receiving pump

information (Appendix K) the team chose the Grundfos 16S07-8 (¾ HP) pump.

The pump curve for the Grundfos 16S07-8 (¾ HP) pump was put into 8 different EPANET

models (one for each zone), and it was found that 45-55 psi was provided at most sprinkler

heads. The sprinkler heads require at least 40 psi, so the pump will provide adequate pressure,

which is within the recommended pressure range of the sprinkler heads (30-70 psi). The mean

velocity (V) was initially estimated at 4 feet per second. After modeling the 8 different

irrigation zones in EPANET with the specified pump curve, it was confirmed by looking at the

velocities in each pipe that this was a reasonable estimate.

26

j. Pipe Selection and Sizing

The stormwater management system for the green roof was designed to handle both a

100-year, 24-hour rain event and snow melt from the snow load used to design the building (40

lb. / ft2). The probability of this event occurring is very low, but using this event for design will

ensure an adequate safety factor for the pipe sizes. Three downspout pipes are to be used to

convey drainage and runoff from the green roof to the cisterns. For a layout drawing which

shows the locations of the downspouts and drainage areas of the green roof that drain to each

downspout pipe, see Figure 9. The downspout pipes are to be PVC pipes, which will be installed

inside the walls of the commons building. This will be done to prevent water from freezing, and

also to be more aesthetically pleasing.

Figure 9: Plan View of Drainage System

A peak discharge was calculated at the top of each downspout using the rational

method. The rational method was used because it assumes no initial abstraction. This is a

good assumption for the design condition, because saturated soil conditions were assumed.

27

Under saturated soil conditions, the soil acts like concrete and runoff occurs immediately. The

rational method was also used because it works well for drainage areas less than 40 acres. The

complete calculations, variable definitions, and assumptions made to find the peak flow rates

of the downspouts are shown in Appendix O. The time of concentration was originally

calculated using the Federal Aviation Administration equation (Mays, 566). However these

values were so low that an intensity value could not be read from the IDF curve (See Appendix

P). Therefore, the time of concentration was assumed to be 15 minutes, because this is a

typical lower limit that is commonly used in industry. The entire snow load (40 lbs/ft2) was

assumed to melt at an even rate over the time of the 24 hour storm. A snow melt flow rate was

calculated and added to the peak flow rate (from the rational method) for each drainage area

to yield the total flow rate. These results are summarized in Table 7.

Table 7: Peak Flow Rates for Downspouts

Peak Flow Rates (ft3 / s)

Area (ft2)

Area (acres) L (ft.) S (%)

Rational Method Snow Load Total

*Drainage Area 1 3,304 0.076 136 2 0.48 0.025 0.50

*Drainage Area 2 8,383 0.192 169 2 1.21 0.062 1.28

*Drainage Area 3 10,057 0.231 186 2 1.46 0.075 1.53

*See Figure 9 for layout drawing of drainage areas

These peak flow rates for each downspout were then used in the orifice equation to

calculate the diameters of the downspout pipes (See Appendix Q). These results are

summarized in Table 8. The orifice equation was used because the downspout pipes are

vertical and can be modeled as holes.

The downspout pipes will convey water from the top of the green roof to drainage

pipes. The drainage pipes will take the water to collector pipes. The collector pipes will bring

the water to underground storage cisterns. The first two drainage pipes will form at “T” and

collect in the first collector pipe. This pipe will then form another “T” with the third drainage

pipe, leading to a second collection pipe. Table 8 shows the calculated and actual diameters of

the collection and downspout pipes. To calculate the drainage pipe and collection pipe

28

diameters, the peak flow rates from the downspouts were used along with Manning’s equation

(See Appendix R).

Table 8: Downspout and Collection Pipe Diameters

Pipe Calculated Diameter (in.)

Actual Diameter (in.)

Downspout 1 4.33 6

Downspout 2 6.92 8

Downspout 3 7.57 8

Drainage 1 5.39 6

Drainage 2 6.46 8

Drainage 3 6.46 8

Collection 1 8.68 10

Collection 2 10.95 12

Another pipe was proposed to convey water from the cisterns to an existing storm

sewer manhole. Water would flow to this manhole when the cisterns would reach capacity.

This pipe was chosen to be the same size as the second collection pipe (12 inches) because it

would need to carry the same water capacity during a storm. The team concluded that the

existing storm sewer system would not be overwhelmed during a heavy rainfall by the addition

of this pipe. The impervious area from which stormwater in this manhole is collected would be

decreased by the addition of the green roof.

k. Stormwater Collection and Conveyance

The green roof will have a 2% slope from north to south. All of the surface runoff from

the grass as well as the water conveyed through the drainage layer will be collected in a

channel, which will be included on the entire south end of the green roof. This channel will be

sloped at 1%, and will convey water to the three downspout pipes (See Figure 9).

The drainage channel will be covered with a 10.5 inch wide plastic grate which will be at

the same level as the grass on the green roof. This grate will be supported by 2”x 6”treated

lumber studs, which will be spaced at 48 inch intervals along the channel. If a 320 pound

person were to stand on the center of a 48 inch span of grate, it would feel “firm” (Table 9).

29

Table 9: Point Load Capacities for Plastic Grate

Point Load (Center of Panel)

Load (lb.)

Span (inches) “Normal” “Firm”

12 >3000 >3000

18 >3000 2288

24 2245 1496

36 849 535

48 497 320 “Normal" is the load (in pounds) that will produce a deflection of 0.375" (accepted as providing a "Normal" feel for foot traffic). “Firm" is the load (in pounds) that will produce a deflection of 0.250" (accepted as providing a "Firm" feel for foot traffic). All deflections are presented in inches. Loads are presented in pounds Source: http://www.century-composites.com/Products/deflection1x4.aspx

To prevent soil erosion, a geotextile fabric will be placed against the soil adjacent to the

channel, which will act as a barrier between the water in the channel and the soil. Manning’s

equation was used to design the channel (see Appendix S). The value for the width of the

channel was changed until the total flow rate was just above the peak flow rate of the largest

downspout. The width of the channel that ensured this condition was 7.5 inches.

l. Optional Gravel Filtration Bed

To ensure a higher degree of water quality in the collected stormwater from the green

roof, the installation of a gravel filtration bed before the cistern could be considered. The gravel

bed would be used to clean the runoff from the roof to prevent damage to the pump and

irrigation system. The team felt that the collected stormwater runoff from the green roof

would be clean enough for irrigation re-use after passing through the geotextile fabric on the

drainage layer. However, if the storwater quality is deemed inadequate by Calvin, the team

allotted space in front of the cistern to accommodate a gravel filtration bed.

7. Structural Design

In order to accurately estimate the cost of constructing the green roof the team

determined that a structural model of the new commons building would be needed. This

model could be used to determine the additional structural elements required to support the

http://www.century-composites.com/Products/deflection1x4.aspx

30

green roof. The team modeled the southern half of the new commons building. This included

the area on which the green roof would be placed as well as conventionally roofed areas

immediately adjacent to it. In this way, the team determined that they could use a model to

find the increase in structural steel without taking the time necessary to model the entire

structure. The program RAMSTEEL was used to create two steel designs, one for the commons

building with the currently envisioned roofing system and another with the green roof system.

A comparison of the different roof loadings can be seen in Table 10 below.

Table 10: Design roof loads for the green roof and a standard roof design

The dead loads were based on either standard loads from the ASCE-7 code book or

taken directly from manufacturer’s specifications for the materials. The live loads were taken

from the Michigan building code, but the snow load was used without a drifting factor in order

to save time and because it was determined that this would allow for a slightly more

conservative estimate of the cost difference.

Unfortunately, the only drawings currently available of the new commons structure

were conceptual drawings of the proposed design. However, as the team was only using the

model for cost estimation and not design purposes it was decided that an approximate model

31

of the structure based on the available drawings would be accurate enough. In order to ensure

accuracy an approximate loading for each floor was also included in both models. The loading

used for the floors can be seen in Table 11.

Table 11: Floor loads applied to model

These loads are based on design criteria from the ASCE-7 code book and were picked as they

closely modeled the construction of other buildings on Calvin’s campus.

Once the model was completed in Ramsteel, the steel design was validated using the

Load and Resistance Factor Design method of the AISC steel code. (For these calculations

please see Appendix T). After validation, the two models were used to find the weight of steel

required for both a standard roof model as well as a green roof using the Ramsteel takeoff

function. The steel weights for the two models were then compared and the difference

calculated to find the additional structural steel required to support a green roof. This was then

converted into a tonnage basis and combined with a cost estimate of $2,600 per ton for

fabrication and erection provided by Roy Lorenz of Steel Supply and Engineering. The results of

this procedure showed that the green roof would require an additional 94 tons of structural

steel at a cost of $245,000.

The team also used the data output for the loads carried by the columns and foundation

walls to estimate the foundation sizes required to support the two different roof types and thus

find the additional costs incurred to build the foundations. These calculations assumed that

spread footings would be used under the columns and a standard linear footing for the walls.

The team also assumed that the soil under the new commons building would be similar to that

under the Spoelhof Fieldhouse Complex and thus could be designed to with the same 3,000 psf

bearing capacity for the soil. The footing sizes were found by dividing the column load by the

3,000 psf bearing capacity of the soil and then taking the square root of the resulting area to

32

find the required size for a square footing. The length per side was then rounded up to the

nearest 6 inches for ease of construction and then used to calculate the cubic yardage of

concrete required to build them, assuming the foundations were a standard one foot thick. A

similar method was used for the footings for the foundation walls, but the results showed that

there was no size difference between the green roof and standard roof wall footings. These

calculations showed that the green roof would require an additional 32.4 cubic yards of

concrete for its foundations, at a cost of $364 per cubic yard for spread footings, which were

taken from RS Means Construction Cost Index (Waier). The total additional costs of the footings

were found to be approximately $12,000. For complete calculations see Appendix U. For the

green roof design footing layout see Figure 10 below.

Figure 10: Footing layout for the green roof design

This structural model allowed the team to accurately determine the full cost of

constructing the green roof. In addition, a series of prints showing the design results of the

model were created and are included with this report.

33

a. Entry Structure

In addition to the three floors of the commons building, a fourth floor was included in the

structural design. This floor serves as an entryway to the green roof. After viewing the

conceptual drawings of the new Commons building, the team decided to include this structure

in the northeast corner of the proposed green roof because an elevator shaft was nearby. The

team did not design the details of this structure, but simply allotted an appropriate area for

necessary components of this structure. A 20 x 61 foot area was allotted for the entry

structure. This area was chosen in order to provide adequate space for an elevator and

stairwell that would comply with ADA standards. In addition to an elevator shaft and a stairwell,

extra space was allotted for the storage of lawn maintenance equipment. This extra space

would also allow flexibility in the future architectural design of the foyer leading to the green

roof.

8. Cost Analysis

Once the team had completed the design and found the types and amounts of materials

needed to construct the green roof they began the process of estimating the cost of the roof.

The cost estimates were based on a variety of sources. For most of the components including

piping, the roof access structure and railings a current copy of RS Means Construction Cost

Index (Waier) with the costs localized for Grand Rapids MI was used to estimate costs. For

many of the larger components of the roof, including soil, steel, drainage material, and cisterns

the costs estimated were based on quotes provided by suppliers.

a. Hydraulic System

Table 12 shows the capital costs for the various components of the hydraulic system.

34

Table 12: Cost Analysis for Hydraulic System Components

*The price for irrigation system installation includes everything that will be on the roof. This includes sprinkler heads, valves, mainline, laterals, wiring, and installation from a contractor. This price was provided by Spartan Distributors.

Almost all of the cost for the hydraulic system will be in capital costs. This is because

there is very little maintenance that will be required for a conventional irrigation system and

the cost to run the irrigation and cistern pumps will be minimal ($9.82 – see Appendix J).

b. Green Roof and Structural supports

A breakdown of the costs of the green roof and the supporting structural systems can be

seen in Table 13 below.

35

Table 13: Cost of green roof and structural supports

The cost of the roof access was based on an estimate for the cost of a student union taken

from RS Means. Also, the savings portion of the estimate is based on the assumption that the

actual construction would use a standing seam metal roof as shown on the concept drawings.

c. Total cost

The total cost of building the intensive green roof and the irrigation system would be

approximately $700,000 including a 10% contingency. Based on these figures the green roof

costs approximately $31.55 per square foot before any savings and $15.55 per square foot after

savings. This would mean the proposed roof would comprise roughly 2.8% of the total project

budget of $25 million if no cost savings are realized and 1.4% of the budget if the savings are

realized. The annual maintenance cost will be approximately $1080. This includes the cost of

labor required for mowing the grass once a week and the cost of labor for two employees to

clean the drainage channel and cisterns once a year. An additional annual cost of $10 will be

required for the operation of the pumps (see Appendix J).

36

9. Conclusion

Even though West Michigan does not suffer from a scarcity of water resources, it is

Calvin’s duty as a Christian college to use its resources wisely as stewards of God’s creation. A

green roof would be an important way in which Calvin could support these ideals. Moreover,

the project shows that the cost for a fairly large and complex green roof design for the

commons building would be manageable at $700,000 or less than 2.8% of the project budget.

Thus, a green roof would be a good investment for Calvin College.

10. Further Steps

In order to pursue this project, it is recommended that Calvin begin talking with local

engineering firms with experience in green roof design and construction. Calvin should work to

refine the design to further fit their needs. Furthermore they should look for reputable and

experienced contractors to build the green roof as they move into a construction phase.

11. Acknowledgements

Team 14 – Going Green would like to thank all of those who helped us with our project by

giving advice and guidance.

Professor David Wunder – Our team advisor

Professor Bob Hoeksema – For advice about our model of the hydraulic system

Professor Leonard De Rooy- For help with the structural design and cost estimation

Tom Newhof, Prein and Newhof – Our industrial consultant

Charlie Huizinga and Geoff Van Berkel, Calvin Physical Plant – For assistance with

irrigation design

Shirley Hoogstra, Gail Heffner, and Frank Gorman, Calvin College – For their ideas and

help with our project

37

Bruce Funnel and Dan Cummings, Spartan Distributors Inc. – For assistance with

irrigation design and cost estimates

Eric Neubecker, Raymer Water Supply Contractors – For assistance with pump selection

Jim Saxpon, American Wick – for Drainage Layer cost estimates

Roy Lorenz, Steel Supply and Engineering – for steel cost estimates

12. Bibliography

American Institute of Steel Construction. Steel Construction Manual. 13th ed. 2005.

American Society of Civil Engineers. ASCE-7 Minimum Design Loads for Buildings and Other

Structures. 2005.

Bras, Rafael L. Hydrology: An Introduction to Hydrologic Science. Reading, MA: Addison-Wesley

Publishing Company, 1990. 270

Funnel, Bruce. Spartan Distributors Inc. Personal interview. 2009.

Idema, Brett. Kerkstra Precast. Personal interview. 2009.

Lorenz, Roy. Steel Supply and Engineering. Personal interview. 2009.

Mays, Larry W. Water Resources Engineering. Hoboken, NJ: John Wiley & Sons, Inc., 2005.

MDOT Drainage Manual – Appendix 3-D: Wetland Hydrology – The Water Budget:

http://www.michigan.gov/documents/MDOT_MS4_App_91720_7._03_D_Drainage_Manual.pdf

Neubecker, Eric. Raymer Water Supply Contractors. Personal interview. 2009.

Van Berkel, Geoff, and Charles Huizinga. Calvin College Physical Plant. Personal interview. 2009.

Volumt, Jeff. Compost Supply Inc. Personal interview. 2009.

Waier, Phillip R, ed. Building Construction Cost Data. 67th ed. Kingston, MA: RS Means

Company, Inc, 2009.

http://www.michigan.gov/documents/MDOT_MS4_App_91720_7._03_D_Drainage_Manual.pdf

38

Appendix A: Green Roof Soil Specifications

39

Appendix B: Drainage Layer Specifications

40

Appendix C: Hydraulic Model of Green Roof Stormwater Management and Irrigation System

Page 1 (see attached CD for the actual file: Hydraulic_Model.xlsx)

42

Calculations performed by: Michael Dirkse and Mike Vander Ploeg

Calculations checked by: Mike Vander Ploeg and Michael Dirkse

43

Appendix D: Snow Melt Calculations

Snow melt was calculated using equation D-1:

(D-1)

where M is the melt rate [in. /day], and AGR is the area of the green roof [in.2]. The melt rate

was calculated by using equation D-2 (Bras, 270).

(D-2)

In equation D-2, Mf represents the melt factor, Ta is the air temperature, and Tb is the base

temperature. The base temperature is the temperature below which no melt occurs, and it was

assumed to be 0°C. In reality, snow may actually melt when the temperature is below 0°C due

to high solar radiation. Snow could also melt at this temperature due to the temperature

gradient that exists within the snowpack and the energy exchanges that would continue

between the air-snow interface. However, a base temperature of 0°C was considered sufficient

for the model for simplification purposes and because winters in West Michigan are typically

very cloudy.

Solar radiation is a driving factor in determining the rate at which snow melts, and it

varies throughout the year. To account for this variability, equation D-3 was used to determine

the melt factor for each day of the year (Bras, 270).

(D-3)

In equation D-3, represents the maximum value Mf can take, represents the

minimum value it can take, and n represents the day number. The day numbers begin at March

21st (n = 1 on March 21st). The maximum and minimum melt factors were determined by using

Table 1 (Bras, 272, Table 6.4).

44

Table D-1: Typical Values of Melt Factors

Forest Cover

Coniferous forest – quite dense 0.5 - 0.8 0.2 - 0.3

Mixed forest – coniferous plus open and/or

deciduous

0.8 - 1.0 0.25 – 0.4

Predominantly deciduous forest 1.3 0.35 - 0.5

Open Areas 1.3 - 2.0 0.5 - 0.9

*Source: Anderson [1978b], Hydrologic Research Laboratory, National Weather Service/NOAA * Melt factors are related to forest cover for areas with distinct accumulation and melt seasons (Units: mm per °C per 6 hours)

Maximum and minimum melt factors depend on factors such as forest cover, exposure,

and wind. The green roof will be an open area, so melt factors were chosen within the range

given in Table D-1 under “Open Areas.” Exposure will not affect the melt factor on the green

roof very much because it will be relatively flat. Due to its high elevation, very windy conditions

are likely to exist on the green roof. Therefore high melt factors within the “Open Areas” range

were chosen. The maximum melt factor was set to 1.8, and the minimum melt factor was set

to 0.8.

By using the melt factor and melt rate described in the above equations, a water-

equivalent volume of snow melt was calculated for each day of the year if there was any snow

accumulation on the roof.

Calculations performed by: Michael Dirkse Calculations checked by: Mike Vander Ploeg

For complete results see the snow melt tab in Hydraulic_Model.xlsx

45

Appendix E: Evapotranspiration Calculations

In the evapotranspiration calculations for the green roof, the Thornthwaite-Mather

method was used. This method was a recommended according to the Wetland Hydrology

section of the MDOT Drainage Manual. The team used the Thornthwaite equation (E-1) to

calculate potential evapotranspiration (PET):

(E-1)

where:

Ta = Mean Monthly Air Temperature

(E-2)

The monthly heat index (I) was computed by equation E-3 over a 12 month period:

(E-3)

However, I must be adjusted for a specific latitude and month. Table E-1 uses linear

interpolation to calculate the correction factors for monthly sunshine duration for the latitude

at Grand Rapids. The PET was calculated by multiplying the original PET value by the correction

factor in the table below.

Table E-1: Correction Factors for Monthly Sunshine Duration

Latitude (N) Jan. Feb. Mar. Apr. May. Jun. Jul. Aug. Sep. Oct. Nov. Dec.

50 0.71 0.84 0.98 1.14 1.28 1.36 1.33 1.21 1.06 0.9 0.76 0.68

42.96 0.77 0.88 0.99 1.11 1.22 1.28 1.26 1.17 1.05 0.92 0.81 0.75

40 0.8 0.89 0.99 1.1 1.2 1.25 1.23 1.15 1.04 0.93 0.83 0.78 *The values for 40 N and 50 N latitude were taken from Dunne and Leopold (1978) *The value for the latitude of Grand Rapids was obtained from: http://www.citytowninfo.com/places/michigan/grand-rapids.

Table E-2 shows the evapotranspiration calculations for the wet year (1986).

Evapotranspiration data for the other two years was calculated in a similar way (Tables E-3 and

E-4). The value for PET was multiplied by the area of the green roof to obtain the daily volume

http://www.citytowninfo.com/places/michigan/grand-rapids

46

of water that exited the green roof through evapotranspiration. This volume of water was

subsequently used to calculate the volume of water that was in the soil on any given day (See

Appendix F).

Table E-2: Evapotranspiration Calculations for the Wet Year (1986)

Wet Year 1986 Total Days Avg. Temp I /mo PET Adjusted PET PET PET

C

mm/mo mm/mo in/mo in/day

Jan 31 -5.16 0.00 0.00 0.00 0.00 0.0000

Feb 29 -5.32 0.00 0.00 0.00 0.00 0.0000

Mar 31 2.62 0.38 9.46 9.34 0.37 0.0119

Apr 30 9.81 2.75 43.09 47.91 1.89 0.0629

May 31 14.87 5.13 69.37 84.88 3.34 0.1078

Jun 30 18.01 6.84 86.43 110.86 4.36 0.1455

Jul 31 22.52 9.56 111.68 140.67 5.54 0.1787

Aug 31 18.87 7.33 91.19 106.49 4.19 0.1352

Sep 30 17.12 6.34 81.56 85.31 3.36 0.1120

Oct 31 10.09 2.87 44.48 40.97 1.61 0.0520

Nov 30 1.64 0.19 5.53 4.48 0.18 0.0059

Dec 31 -1.22 0.00 0.00 0.00 0.00 0.0000

I= 41.37

a= 1.15

Table E-3: Evapotranspiration data for the Average Year (1968)

Avg Year 1968 Total Days Avg. Temp I /mo PET Adjusted PET PET PET

C mm/mo mm/mo in/mo in/day

Jan 31 -6.11 0.00 0.00 0.00 0.00 0.0000

Feb 29 -5.92 0.00 0.00 0.00 0.00 0.0000

Mar 31 3.33 0.54 12.14 11.98 0.47 0.0152

Apr 30 9.31 2.54 39.96 44.43 1.75 0.0583

May 31 12.19 3.81 54.69 66.92 2.63 0.0850

Jun 30 19.25 7.55 92.90 119.15 4.69 0.1564

Jul 31 20.97 8.59 102.61 129.25 5.09 0.1642

Aug 31 21.44 8.88 105.30 122.96 4.84 0.1562

Sep 30 17.58 6.59 83.63 87.47 3.44 0.1148

Oct 31 10.97 3.25 48.38 44.56 1.75 0.0566

Nov 30 3.25 0.52 11.79 9.54 0.38 0.0125

Dec 31 -4.31 0.00 0.00 0.00 0.00 0.0000

I= 42.29

a= 1.16

47

Table E-4: Evapotranspiration data for the Dry Year (1962)

Dry Year 1962 Total Days Avg. Temp I /mo PET Adjusted PET PET PET

C mm/mo mm/mo in/mo in/day

Jan 31 -7.06 0.00 0.00 0.00 0.00 0.0000

Feb 28 -5.81 0.00 0.00 0.00 0.00 0.0000

Mar 31 0.33 0.02 0.77 0.76 0.03 0.0010

Apr 30 7.69 1.91 31.24 34.73 1.37 0.0456

May 31 17.19 6.38 80.77 98.84 3.89 0.1255

Jun 30 20.11 8.07 97.19 124.66 4.91 0.1636

Jul 31 20.69 8.42 100.53 126.63 4.99 0.1608

Aug 31 21.50 8.92 105.17 122.81 4.84 0.1560

Sep 30 15.75 5.59 72.81 76.16 3.00 0.0999

Oct 31 11.81 3.63 51.80 47.71 1.88 0.0606

Nov 30 4.11 0.75 14.90 12.06 0.47 0.0158

Dec 31 -4.19 0.00 0.00 0.00 0.00 0.0000

Total I= 43.67

a= 1.18

Calculations performed by: Mike Vander Ploeg Calculations checked by: Michael Dirkse

48

Appendix F: Drainage and Runoff Calculations

To properly calculate the volumes of drainage and runoff from the green roof, the

amount of water in the soil layer of the green roof was calculated for each day. The soil on the

green roof has a porosity of 0.53, so 53% of the soil volume was assumed to be empty space

that could be filled with water. The saturated soil volume (the total volume within the soil that

water could occupy) was calculated by multiplying the soil depth, the green roof area, and the

soil porosity. The daily volume of water in the soil (Vsoil) was calculated using equation Q-1:

(Q-1)

Vsoil_prev represents the volume of water in the soil from the previous day. Vpumped represents the

volume of water that was pumped from the cisterns to the green roof for irrigation for that day.

R represents a daily volume of rainfall, SM represents the daily volume of snow melt, and ET

represents the volume of water leaving the green roof through evapotranspiration.

Calculations performed by: Mike Vander Ploeg

Calculations checked by: Michael Dirkse

49

Appendix G: Irrigation Controller Specifications

51

Appendix H: Comparison of Timed Irrigation to Irrigation Based on Soil Moisture

Calculations performed by: Michael Dirkse

Calculations checked by: Mike Vander Ploeg

52



53

Appendix I: Sprinkler Head Specifications

54

Appendix J: Annual Energy Costs for Pumps

Table J-1: Annual Energy Costs for Pumps

Symbol Cistern Pump Irrigation Pump Volume pumped in 3 years (gal.) 257,963 183,669 Average Volume pumped per year (gal.) Vpumped 85,988 61,223 Pump Power (HP) P 0.75 5 Average Flow Rate (gpm) Qavg 12.5 160 Price of Electricity ($/kWh) Pelec 0.1117 0.1117 Annual Energy Cost Cannual $7.16 $2.66 Total Annual Energy Cost for Pumps = $9.82

*The Cistern pump pumps water from the cisterns to the green roof *The Irrigation pump pumps water from the current irrigation system at Calvin to the cisterns

Note: The price of electricity was based on an estimate of the cost of residential electricity in Michigan in 2009

Source: http://www.eia.doe.gov/cneaf/electricity/epm/table5_6_b.html#_ftn1 The following equation was used in the calculation



55

Appendix K: Pump Curves and Specifications

57

Pipe Headloss Calculations

This is a sample calculation for the pipe head loss in irrigation zone 1. This calculation was carried out multiple times for each irrigation zone.

Length of pipe in irrigation zone

Diameter of pipe

Mean velocity of water flowing through the pipe

Kinematic viscosity of water at 70 F

Source: Water Resources Engineering by Mays pg. 16 Table 2.1.1

Reynolds Number

Pipe friction factor, which was obtained from the Moody Diagram. Since the pipe material is PVC, a smooth pipe was assumed, and the corresponding curve was used to find the friction factor.

Darcy-Weisbach equation

Pipe head loss

L 140ft

D 1 in

V 4ft

s

1.059105 ft

2

s

ReV D

Re 3.148 104

f 0.023

hL fL

D

V2

2g

hL 9.608ft

58

Appendix L: Minor Head losses Due to Pipe Bends

Head Losses in each zone

From the Pump to the roof:

Resistance

Coefficient (K) Quantity HL (ft.)

90 degree bends 0.3 5 0.37

Entrance, square edged 0.5 1 0.12

Check Valve 2.5 1 0.62

1.12

Friction factor= 0.023

Mean Velocity= 4 ft/s

g= 32.2 ft/s2

Zone 1 Coefficient (K) Quantity HL (ft.)


T Bend - flow through run 0.6 2 0.30

0.67

Zone 2


T Bend - flow through side outlet 1.8 1 0.45


T Bend - flow split side inlet to run 1.8 1 0.45

1.57

Zone 3



0.75

Zone 4


59

45 degree bend 0.2 1 0.05


0.42

Zone 5


45 degree bend 0.2 1 0.05


0.80

Zone 6




0.82

Zone 7




1.04

Zone 8



T Bend - flow split side inlet to run 1.8 1 0.45

1.49


60

Appendix M: Head losses for Pipes in each Irrigation Zone


This is a sample calculation for the pipe headloss in irrigation zone 1. This calculation was carried out multiple times for each irrigation zone.

Length of pipe in irrigation zone

Diameter of pipe

Mean velocity of water flowing through the pipe

Kinematic viscosity of water at 70 F Source: Water Resources Engineering by Mays pg. 16 Table 2.1.1

Reynolds Number

Pipe friction factor, which was obtained from the Moody Diagram. Since the pipe material is PVC, a smooth pipe was assumed, and the corresponding curve was used to find the friction factor.

Darcy-Weisbach equation

Pipe headloss

L 143.3ft

D 1 in

V 4ft

s

1.059105 ft

2

s

ReV D

Re 3.148 104

f 0.023

hL fL

D

V2

2g

hL 9.834ft

61

Appendix N: Pump Head Calculations Calculations performed by: Michael Dirkse Calculations checked by: Mike Vander Ploeg

Point 1 - At the surface of the water in the tank at its lowest level Point 2 - At a point just before the last sprinkler head

Specific weight of water at 70 F Source: http://www.engineeringtoolbox.com/water-density-specific-weight-d_595.html

Velocity of the water at point 1 Pressure of the water at point 1

Elevation at point 1

Depth of tank burial (below ground level)

Elevation of the green roof (from ground level

Diameter of tank

Elevation at point 2

Diameter of sprinkler head inlet

Cross-sectional area of sprinkler head inlet

Flow rate at the last sprinkler head of zone 2

Velocity of water at point 2

Pressure loss due to flow through zone 2 valve

Pressure required at last sprinkler head

Pressure at point 2

Total headloss in zone 2. Zone 2 had the highest headloss of all the zones. See Headolss_Calcs.xlsx for complete calculations.

Energy Equation - solved for pump head:

Pump head

62.30lb

ft3

V1 0 P1 0

z1 0

zburial 3 ft

zroof 37 ft

dtank 10 ft

z2 zburial dtank zroof z2 50ft

dinlet 0.75 in

Ainlet

dinlet

2

2

Qzone_2 2.4gal

min

V2

Qzone_2

Ainlet

V2 1.743ft

s

Ploss 3lb

in2

Psprinkler 40lb

in2

P2 Ploss Psprinkler P2 43lb

in2

hL 29.25ft

hp

V22

2 g

V12

2 g

P2 P1z2 z1 hL hp 178.687ft

62

Appendix O: Peak Flow Rate Calculations for Downspouts


63

Appendix P: IDF Curve for Kent County

Source: http://www.accesskent.com/YourGovernment/DrainCommisioner/pdfs/DrainageRules_B5.pdf

64

Appendix Q: Downspout Size Calculations Calculations performed by: Mike Vander Ploeg Calculations checked by: Michael Dirkse

Peak flow rates for each downspout. These flow rates were calculated using the rational method and snow melt flow rates. (See Appendix O for complete peak flow rate calculations for downspouts)

Coefficient of discharge for a tube Source: http://engineering.wikia.com/wiki/Orifice_equation

Height of concrete wall at the edge of the green roof

Orifice Equation (solved for area): Source: http://engineering.wikia.com/wiki/Orifice_equation

Diameters of each downspout:

Actual Diameters of downspouts: Downspout 1 = 6 inches Downspout 2 = 8 inches Downspout 3 = 8 inches

Qpeak_1 0.5ft

3

sQpeak_2 1.28

ft3

sQpeak_3 1.53

ft3

s

Cd 0.8

g 32.174ft

s2

h 7 in

A1

Qpeak_1

Cd 2 g hA2

Qpeak_2

Cd 2 g hA3

Qpeak_3

Cd 2 g h

d1

4 A1d2

4 A2d3

4 A3

d1 4.325in d2 6.92in d3 7.565in

65

Appendix R: Drainage and Collection Pipe Calculations Calculations performed by: Mike Vander Ploeg Calculations checked by: Michael Dirkse

Peak flow rates for each of the downspouts (See Appendix L for complete calculations)

The following characteristics of the channel were assumed by the team

Manning's roughness coefficient for PVC Source: Water Resources Engineering by Mays, page 90, Table 5.1.1

Manning's Equation: Source: Water Resources Engineering by Mays, page 93

For drainage pipe 1:

Bed slope of channel

Check for self flushing drainage 3ft/s




Qpeak_1 0.5 Qpeak_2 1.28 Qpeak_3 1.53ft3

s

ft3

s

ft3

s

n .011

Q1 Qpeak_1 S1 .01

D1 16Q1 n

S1.5

3

8

D1 5.392 inV1

144Q1

3.14

4D1

2

V1 3.155ft

s

Q2 Qpeak_2 S2 .025

D2 16Q2 n

S2.5

3

8

D2 6.46 V2

144Q2

3.14

4D2

2

V2 5.627ft

s

66




For First Collection Pipe:



For Second Collection Pipe:



Q3 Qpeak_3 S3 .18

D3 16Q3 n

S3.5

3

8

D2 6.46 V3

144Q3

3.14

4D3

2

V3 12.334ft

s

Qc1 Qpeak_1 Qpeak_2 Sc1 .01

Dc1 16Qc1 n

Sc1.5

3

8

Dc1 8.681 Vc1

144Qc1

3.14

4Dc1

2

Vc1 4.333ft

s

Qc2 Qpeak_1 Qpeak_2 Qpeak_3 Sc2 .01

Dc2 16Qc2 n

Sc2.5

3

8

Dc2 10.954 Vc2

144Qc2

3.14

4Dc2

2

Vc2 5.06ft

s

67

Appendix S: Drainage Channel Size Calculations Calculations performed by: Mike Vander Ploeg Calculations checked by: Michael Dirkse

Peak flow rates for each of the downspouts (See Appendix L for complete calculations)

The following characteristics of the channel were assumed by the team


Manning's roughness coefficient for concrete culvert with bends, connections, and some debris Source: Water Resources Engineering by Mays, page 90, Table 5.1.1

Height of the soil layer (ft.)

Height of the drainage layer (ft.)

Height of the membrane (ft.)

Total height of the channel (ft.)

Width of the channel (ft.)

Manning's Equation: Source: Water Resources Engineering by Mays, page 93

Flow Rate through channel (ft3/s)

Qpeak_1 0.5ft

3

sQpeak_2 1.28

ft3

sQpeak_3 1.53

ft3

s

S0 .01

n .013

hsoil 0.5

hdrainage_layer 0.0833

hmembrane 0.03125

h1 hsoil hdrainage_layer hmembrane

h1 0.615

b 0.625

Q1.49

nb h1

b h1

b 2 h1

2

3

S0

1

2

Q 1.541

68

Appendix T: Beam and Column Check Calculations

Calculations performed by: Jeff Bergman Calculations checked by Mike Vander Ploeg

Beam Calculations

General

LLfloor 100 psfDLfloor 63 psf TLfloor 1.6 LLfloor 1.2 DLfloor

LLroof 35 psfDLroof 24.5 psf

TLroof 1.6 LLroof 1.2 DLroof

DLGroof 62.5 psf LLGroof 100 psfTLGroof 1.6 LLGroof 1.2 DLGroof

Note: all maximum values taken from AISC tables 3-6 and 3-10 and the floor and roof decking is

assumed to provide bracing for the beams

Floor 1

Beam #92:W16X31

L92 31.25ft Tributarywidth92 5 ft

w92 TLfloor Tributarywidth92 w92 1.178kip

ft

Mu92

w92 L922

8 Mu92 143.799kip ft

MnW16X31 202.5kip ft

WMax92 52.3kip

ft

Since Mu92 is less than MnW16X31 and w92 is less than WMax92 this design is correct

Beam #255:W14X22

L255 22.5 ft Tributarywidth255 5 ft


ft

Mu255

w255 L2552

8 Mu255 74.545kip ft


WMax255 43.3kip

ft


69

Girder #197:W24X55

L197 21.25 ft Tributarywidth197 15 ft 16.25 ft


ft

Mu197

w197 L1972

8 Mu197 415.579kip ft


WMax197 183kip

ft


Girder #250:W30X90

L250 37.5 ft Tributarywidth25023.75

2ft

22.5

2ft


ft

Mu250

w250 L2502

8 Mu250 957.7kip ft

MnW30X90 1061kip ft

WMax250 223kip

ft


Floor 2

Beam #271:W10X12

L271 15 ft Tributarywidth271 5 ft


ft

Mu271

w271 L2712

8 Mu271 33.131kip ft

MnW10X12 47kip ft

WMax271 25kip

ft

70

MnW10X12 47kip ft

WMax271 25kip

ft


Beam #195:W16X31



ft

Mu195

w195 L1952

8 Mu195 132.525kip ft


WMax195 54kip

ft


Girder #135:W24X76

L135 35 ft Tributarywidth1355

2ft

31.25

2ft


ft

Mu135

w135 L1352

8 Mu135 653.882kip ft

MnW24X76 750kip ft

WMax135 167kip

ft


Girder #14:W14X22



ft

Mu14

w14 L142

8 Mu14 103.535kip ft

71


WMax14 52.4kip

ft


Floor 3

Beam #32:W21X44



ft

Mu32

w32 L322

8 Mu32 207.07kip ft

MnW21X44 340kip ft

WMax32 75.3kip

ft


Beam #89:W12X19



ft

Mu89

w89 L892

8 Mu89 66.493kip ft

MnW12X19 92.5

WMax89 33.7kip

ft


Girder #85:W27X84

L85 30 ft Tributarywidth8537.5

2ft

21.25

2ft


ft

Mu85

w85 L852

8

72

w85 6.921kip

ft

Mu85

w85 L852

8 Mu85 778.584kip ft

MnW27X84 915kip ft

WMax85 244kip

ft


Girder #108:W16X26


2ft

31.25

2ft


ft

Mu108

w108 L1082

8 Mu108 120.101kip ft

MnW16X26 165.7

WMax108 88.4kip

ft


Green Roof

Beam #261:W21X48


w261 TLGroof Tributarywidth261 w261 1.175kip

ft

Mu261

w261 L2612

8 Mu261 265.293kip ft

MnW21X48 398kip ft

WMax261 72.4kip

ft


Beam #111:W18X40


73


ft

Mu111

w111 L1112

8 Mu111 193.003kip ft

MnW18X40 294

WMax111 63.6kip

ft


Girder #74:W40X215

L74 56.25ft Tributarywidth7431.5

2ft

37.5

2ft


ft

Mu74

w74 L742

8 Mu74 3.207 103

kip ft

MnW40X215 3615kip ft

WMax74 499kip

ft


Girder #15:W33X130

L15 43.75ft Tributarywidth1520

2ft

36.25

2ft


ft

Mu15

w15 L152

8 Mu15 1.581 103

kip ft

MnW33X130 1751kip ft

WMax15 318kip

ft


Roof Access

74

Beam #336:W8X10


w336 TLroof Tributarywidth336 w336 0.427kip

ft

Mu336

w336 L3362

8 Mu336 12.009kip ft

MnW8X10 32.9kip ft

WMax336 17.5kip

ft


Beam #331:W10X12



ft

Mu331

w331 L3312

8 Mu331 21.35kip ft

MnW10X12 47kip ft

WMax331 18.8kip

ft


Girder #318:W12X14


2ft

5

2ft


ft

Mu318

w318 L3182

8 Mu318 42.7kip ft

MnW12X14 65.3kip ft

WMax318 26.1kip

ft


75

Girder #322:W14X22

L322 23.75 ft Tributarywidth32220

2ft


ft

Mu322

w322 L3222

8 Mu322 60.214kip ft


WMax322 41.5kip

ft


Standard Roof

Beam #260:W16X31



ft

Mu260

w260 L2602

8 Mu260 96.409kip ft


WMax260 41.5kip

ft


Beam #53:W14X22



ft

Mu53

w53 L532

8 Mu53 70.138kip ft


WMax53 29.3kip

ft

76


Girder #44:W33X130

L44 62.5 ft Tributarywidth4432.5

2ft

30

2ft


ft

Mu44

w44 L442

8 Mu44 1.303 103

kip ft

MnW33X130 1.751 103

kip ft

WMax44 219kip

ft


Girder #190:W30X99

L190 56.25ft Tributarywidth19018.75

2ft

31.25

2ft


ft

Mu190

w190 L1902

8 Mu190 844.409kip ft

MnW30X99 1170kip ft

WMax190 161kip

ft


77

Column Checks

Standard Roof

k 1 Based on AISC code this is the maximum value required

note: al l bearing capacities based on Table 4-4 of AISC code and all loads taken from Ram steel

Roof Level to Second Story HSS12X12X5/16

length sroof 24 ft

k length sroof 24ft

Capacitysroof 434 kip

Loadsroof 194.47kip

The Capacitysroof exceeds Loadsroof so this des ign is correct

Second Story to Firs t Story HSS12X12X3/8

length s2 12 ft

k length s2 12ft

Capacitys2 621 kip

Loads2 477.29kip

The Capacitys2 exceeds Loads2 so this des ign is correct

Firs t Story to Basement HSS12X12X1/2

length s1 12 ft

k length s1 12ft

Capacitys1 812 kip

Loads1 759.59kip

The Capacitys1 exceeds Loads1 so this des ign is correct

Green Roof

Roof Level to Second Story HSS16X16X1/2

length groof 24 ft

k length groof 24ft

Capacitygroof 1010kip

Loadgroof 452.86kip

The Capacitygroof exceeds Loadgroof so this des ign is correct

78

Second Story to Firs t Story HSS16X16X1/2

length g2 12 ft

k length g2 12ft

Capacityg2 1130kip

Loadg2 800.51kip

The Capacityg2 exceeds Loadg2 so this des ign is correct

Firs t Story to Basement HSS16X16X1/2

length g1 12 ft

k length g1 12ft

Capacityg1 1130kip

Loadg1 1083.27kip

The Capacityg1 exceeds Loadg1 so this des ign is correct

Roof Access Column HSS 12X12X3/16

length gra 12 ft

k length gra 12ft

Capacitygra 209 kip

Loadgra 11.32kip

The Capacitygra exceeds Loadgra so this des ign is correct

79

Appendix U: Foundation Design and Calculations Performed by: Jeff Bergman Checked by: Mike Vander Ploeg

81

Standard Roof

Level Pu Mux Column Size Foundation Length (ft)

Column Line 31.25ft - 35.00ft Level 0 254.9 25.5 HSS12X12X1/4 9.5

Column Line 31.25ft - 71.25ft Level 0 506.1 17.7 HSS12X12X3/8 13

Column Line 31.25ft - 107.50ft Level 0 303.1 6 HSS12X12X1/4 10.5





Column Line 56.25ft - 127.50ft Level 0 500 16.8 HSS12X12X3/8 13




Column Line 62.50ft - 15.00ft Level 0 188 4.2 HSS12X12X1/4 8

Column Line 62.50ft - 35.00ft Level 0 437 28.9 HSS12X12X3/8 12.5

Column Line 75.00ft - 15.00ft Level 0 479.6 32 HSS12X12X3/8 13






Column Line 93.75ft - 220.00ft

82

Level 0 406.7 0 HSS12X12X5/16 12








Column Line 131.25ft - 220.00ft Level 0 373 11.1 HSS12X12X5/16 11.5






Column Line 175.00ft - -7.50ft

Wall Load 678 kips Length 90 ft Load 7.53 klf Width 2.51 ft Actual Width 3.00 ft

83

Foundation Formulas

Column Spread Footings

Footinglength

Pu

Soilbearingpressure

The result was then rounded up to the nearest 6"

Wall Footings

LoadWallload

WalllengthNote: The wall with the greatest line load per unit length was used

FootingwidthLoad

Soilbearingpressure

The resulting width was then rounded up to the nearest 6"

2009 final report team 14

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