architectural engineering spring 2004 senior thesis · water reheating coils. it is serviced by two...

Architectural Engineering Spring 2004 Senior Thesis

Brennan Hall: • Five-story classroom and office building • 68,500 square feet • $12.3 million project • First two floors primarily classrooms • 3rd and 4th floors primarily faculty offices • 5th floor executive board room/catering

Mechanical: • VAV system with up to 3000 CFM • Hot water reheat coils • 100 & 132 Ton rotary liquid chillers • Two 1892 MBH cast iron boilers

Structural: • Structural steel framing • Fully rigid moment frames • Concrete-filled composite metal deck • Column spread & continuous wall footings

Primary Project Team: • Owner: University of Scranton • GC/CM: Sordoni Construction Services, Inc.• Architects: Burkavage Design Associates • Engineers: QproQ Engineering, Inc. • Geotech: Geo-Science Engineering Co, Inc.

Construction: • Started March 1999 • Completed August 2000 • CM at risk delivery method • Adjacent dorms constructed at same time • Subcontractor lump sum bids

Architectural: • Prominent six-story tower • Brick and cast stone façade with glazing • Symmetrical appearance • 140 seat auditorium

Lighting/Electrical: • 1st & 2nd floor halls: compact fluorescent • 3rd & 4th floors: 3-lamp fluorescent fixtures • 480/277V, 3 phase, 4 wire + ground • 1000 amp main bus • 750 kVA pad mount distribution transformer • 125 W emergency battery units

i Pennsylvania State University

Architectural Engineering Department

Architectural Engineering Douglas Wisniewski Senior Thesis

Kania SOM / Brennan Hall

Credits/Acknowledgements I would like to thank the following people for their time, their energies, and for all of the information that they have provided me with.

James Devers, AIA, Director, University of Scranton Physical Plant Don Flynn, Project Architect, Burkavage Design Associates Linda Hanagan, PhD, PE, Assistant Professor, Penn State University James Kerns, PE, Principal, QproQ Engineering, Inc. Francis Kranick, CAD Operator, University of Scranton Physical Plant M. Kevin Parfitt, Associate Professor, Penn State University Andrew Shedlock, Project Manager, Sordoni Construction Services Ronald Skutnick, Director, University of Scranton Network Resources David Wilson, AIA, Staff Architect, University of Scranton Physical Plant David Wisniewski, Sr. Principal Systems Engineer, Raytheon

Without their generous contributions, completion of this project would not have been possible. I would also like to thank my parents. Their encouragement and support has proved invaluable throughout my Penn State career. But above all, I cannot forget to thank my Lord and Savior Jesus Christ. It is from Him that I have received my strength and perseverance. I owe all of my past, present, and future successes to Him.

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Table of Contents Thesis Abstract .................................................................................................................... i Credits/Acknowledgements........................................................................................... ii Table of Contents ............................................................................................................... iii Executive Summary ...........................................................................................................1 Project Background

Introduction............................................................................................................2 Project Team...........................................................................................................3 Building Systems....................................................................................................4

Structural Depth Study

Loads.........................................................................................................................7 Lateral System – Reinforced Concrete Shear Walls

o Advantages................................................................................................10 o Proposed Solution ...................................................................................10 o Shear Wall Design ...................................................................................12

Gravity System – Open Web Steel Joists o Advantages/Concerns ...........................................................................17 o Proposed Solution ...................................................................................17 o Fire Protection ..........................................................................................19 o Floor Vibrations........................................................................................20

Scheduling/Cost Breadth Study

Material Costs .........................................................................................................21 Construction Schedule ........................................................................................23 Final Cost Figures..................................................................................................26

Wireless LAN Breadth Study

Advantages.............................................................................................................27 Access Points ..........................................................................................................28 IP Phones .................................................................................................................30 Interactive Whiteboards .....................................................................................31 Video Conferencing.............................................................................................31

Summary and Conclusions..............................................................................................32 Works Cited ..........................................................................................................................34 Appendix A

Foundation Plan....................................................................................................A-1 Appendix B

Sample Calculations .............................................................................................B-1

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Executive Summary Brennan Hall is a five-story office/classroom building surrounded by other structures and a small green space. Floor to floor heights are typically 14 feet, with the roof topping off around 70 feet. The top of the tower reaches nearly 90 feet above grade. Gravity loads are supported by composite concrete slabs which act compositely with wide flange steel beams. Lateral loads are resisted by a series of rigid moment frames. Moment connections are expensive to construct therefore, it would be advantageous to devise a lateral force resisting system that would be less expensive than Brennan Hall’s existing moment frames. After conducting preliminary investigations on steel braced frames and reinforced concrete shear walls, I decided to pursue the shear walls because they required fewer frame locations. Large lateral loads created overturning problems for each wall which forced me to add additional shear walls and increase the mass of the shear walls and their footings. I analyzed the associated material and construction costs to find out whether the reinforced concrete shear wall system reduced the entire project cost. Considering material costs alone, the shear wall system saves nearly $25,000. In order to establish construction costs, I sequenced the shear wall and structural steel construction. Applying labor and equipment rates, the construction costs totaled just over $128,000. Increasing the construction costs by $103,500, this system provides no cost savings. However, this increased cost accounts for less than a 0.9% increase in the total project cost. On an educational level, the shear wall system was successful. It gave me the opportunity to examine a lateral force resisting system that was largely unfamiliar to me. I also had the chance to explore some of the obstacles and design issues that may stand in the way of such a system. In many cases, steel joists provide an efficient alternative to steel beams. However, two hurdles generally stand in the way; fire protection and floor vibrations. To achieve a two hour fire rating, I selected a rated ceiling assembly from the UL Fire Resistance Directory. For vibrations, I used AISC’s Design Guide11 to check my largest floor bay for human activity and found it satisfactory. Steel joist floor framing appears to be an appropriate framing system.

Incorporating wireless technology is a logical step for Brennan Hall. I have established a data network which operates on the IEEE 802.11a standard. To keep up with technology, I have situated IP phones, interactive whiteboards, and sophisticated video conferencing units. The result is a scheme that is flexible, easy to operate, and takes advantage of today’s available technology.

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Project Background

Introduction The University of Scranton is a comprehensive liberal arts university, a Catholic university, an urban university, and a Jesuit university. Brennan Hall is located on the University of Scranton Campus in Scranton, Pennsylvania. It is the home of the Arthur J. Kania School of Management, the only AACSB (The International Association for Management Education) accredited program in Northeastern Pennsylvania. The Center for Economic Education and the Center for International Business, both aimed at providing greater opportunities for interdisciplinary collaboration with other universities, are also located in Brennan Hall. This facility stands five stories tall and is topped off with a “crowned” tower which serves as the building’s most prominent aesthetic feature. Its 68,500 square feet of floor space house nine classrooms, including two computer classrooms, a tax library, reading and quiet study areas, a behavioral lab used for both teaching

and research, a 140 seat auditorium, lounges, and faculty and administrative offices. In addition, the fifth floor features dining and catering facilities as well as an executive conference center offering a wonderful view of the city of Scranton and the surrounding landscape. Brennan Hall prides itself on being the most technologically advanced structure on campus. It features high-end audio and video facilities with teleconferencing capabilities in the executive conference center as well as the second floor auditorium. Instructional spaces contain specialized podiums giving the instructor touch screen control of the lighting, computing, and audio/video components.

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Project Background

Project Team

Owner: University of Scranton o matrix.scranton.edu

Architects: Burkavage Design Associates

o www.burkavagedesign.com

Engineers: QproQ Engineering, Inc. o www.qproq.com

Geotechnical Consultant: Geo-Science Engineering Company, Inc.

General Contractor: Sordoni Construction Services, Inc.

o www.sordoni-construction.com

Primary Subcontractors: o Masonry and Cast Stone: William J. Everett Co. o Structural Steel: Mid-Valley Contracting Services o Electrical Contractor: G.R. Noto Electrical Construction, Inc. o HVAC Systems: Penn State Mechanical Contractors o Plumbing Systems: G. Ritsick and Sons, Inc.

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Project Background

Building Systems

Architecture - The prominent architectural feature of Brennan Hall is the tower on the West corner of the building. The tower is prominent inside as well, consisting of two spaces that are open to the floor above and an executive board room on the fifth floor. The sides are more subtle, further emphasizing the tower, which suits the classrooms and offices that they house. To minimize traffic through the upper levels of the building, the classrooms are located on the first two floors. While the building is not actually symmetrical, from certain angles it appears so. This apparent symmetry is protected by the placement of additional stairs and elevators in the rear of the building where they are less likely to be seen.

Building Envelope - The exterior walls of Brennan Hall are composed of

masonry veneer and glazing. Both brick and cut stone are used, with the cut stone relieved in the top four levels. In addition to the masonry, veneer sections consist of an air space and light gage metal framing with rigid board insulation. Roofing is a fully adhered EPDM system on tapered insulation and metal roof deck. Open-web steel joists and structural steel girders support all roofing. Lower roofs use a ballasted system with similar framing.

Electrical - Brennan Hall is powered by a 480/277 V, 3 phase, 4 wire +

ground system. The main distribution switchboard has 21 buses, the largest being the 1000 amp main bus. Power is supplied from the power company via a 750 kVA pad mount distribution transformer. All panel boards that are connected to larger equipment, such as air handling units, are supplied with 480/277 V; while panel boards connected to just lighting, receptacles, and smaller equipment are all supplied with 208/120 V. Emergency battery units rated for 125 W are used to allow for egress in the event of a power outage.

Lighting - The first and second floor hallways use sparsely spaced

compact fluorescent downlights. Hallways on the third and fourth floors are better lit, using well spaced three lamp fluorescent fixtures. Offices are generally lit by three lamp fluorescent fixtures as well, while classrooms and conference rooms use a combination of fixtures which allow for variability of lighting. Conference rooms, classrooms, and the auditorium have programmed lighting controls that feature multiple preset arrangements to meet the different activities each room may host. Occupancy sensors are used to switch off lights in unoccupied rooms.

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Mechanical - This building uses a variable air volume system with hot

water reheating coils. It is serviced by two 1892 MBH cast iron boilers which also serve the adjacent dormitory that was constructed at the same time. Water is cooled by two rotary liquid chillers connected to cooling towers. The chillers sit on concrete pads and are separated from the structure by vibration insulators. All ductwork is treated with ½” acoustical lining and is mounted to auxiliary steel with spring hanger rods.

Structural - Brennan Hall is a five-story, steel framed, office/classroom

building with many spaces sized and shaped irregularly. These spaces do not provide many convenient locations for diagonal bracing; therefore rigid moment frames are used to carry lateral loads. Concrete filled metal deck acts compositely with wide flange steel beams and girders which carry loads into the columns. Columns are supported by concrete piers and concrete spread footings which bear on soil.

Construction - Construction of Brennan Hall was started in March of

1999 and completed in August of 2000. Sordoni Construction Services acted as both the general contractor and the construction manager for the project. Subcontractors were brought into the project through lump sum bids. A dormitory building was constructed adjacent to the site at the same time, causing some site congestion.

Fire Protection - Brennan Hall is serviced by a wet pipe sprinkler system.

Recessed pendant sprinkler heads are used in classroom and office areas and concealed sprinkler heads are used in conference and board rooms, as well as the first and second floor hallways, places where appearance is more important. Standpipes with fire hose connections are located in each stairway. Cementitious spray-applied fireproofing was applied to structural steel elements. Fireproofing provides 1 ½ hour rating for floor/ceiling systems and 2 hour rating for columns.

Transportation - There are three hydraulic elevators in two CMU block

framed shafts. The two elevators that share a shaft each have a 2500 lb capacity and travel at speeds of 200 fpm up and 150 fpm down. The other elevator has a 3500 lb capacity and travels at speeds of 140 fpm up and 150 fpm down. All cabs have doors in both the front and the rear. Stairs between the first and second floors wrap around each side in the base of the tower. There are two other stairways, each with 2 runs of stairs per floor. One set runs from the ground to the fifth floor, while the other set runs from the ground to the roof.

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Telecommunications - Throughout its classrooms and its executive conference center, Brennan Hall was designed to showcase information technology. The building’s cable specifications were set to utilize a Category 6 unshielded twisted pair cable plant. Fiber optic cable was used for all riser cables for the data network. A main communication facility is located in the basement, with communication facilities located in a stacked arrangement on each floor. Many instructional rooms are outfitted with raised floors to accommodate specialized cabling to furniture supported technology.

Information Technology - Brennan Hall was designed to showcase

instructional technologies and conference center flexibility. Instructional spaces are equipped with customized podiums which provide touch screen control of the lighting, computing, and audio/video components. These spaces also feature overhead projectors, motorized projection screens, image visualizers, DVD players, CD players, VCRs, audio receivers, speakers, and microphones. Elaborate audio and video configurations providing high-end video displays, theater like sound systems, voice lift facilities, and video teleconferencing capabilities are featured in the executive conference center, as well as two instructional case rooms. A 140 seat auditorium also features theater like audio and video environments.

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Loads

Dead Loads - The dead loads for the materials making up both the roof and floor assemblies are from tables in AISC’s Manual of Steel Construction. The lower roof levels are ballasted with gravel, while the upper roof is not. Therefore, two different roof dead loads are presented. Also, only a few portions of each floor are finished with porcelain tile. Two floor dead loads have been prepared and applied to account for this. Individual material and total assembly dead loads are summarized below.

Dead Loads: from the AISC Manual of Steel Construction

o Roof • Steel joists 3 psf • Mtl. roof deck 1.7 psf • Rigid insulation 2 psf • Single-ply membrane 1 psf • Membrane w/gravel 11 psf • Mechanical 8 psf • Ceiling 1 psf

• Total Roof w/out ballast 16.7 psf • Total Roof W/ballast 26.7 psf

o Floor • Concrete w/comp. mtl. deck 48 psf • Porcelain tile 10 psf • Structural Steel 10 psf • Fireproofing 3 psf • Ceiling 1 psf • Partitions 20 psf • Mechanical 8 psf

• Total Floor w/out tile 90 psf • Total Floor w/tile 100 psf

o Exterior wall • 4” brick w/stud backup 40 psf (wall surface area)

Live Loads - Live loads for various spaces are taken from ASCE 7-02. For

simplicity in loading the structure, a value of 80 psf has been spread over the entire floor area. Since the majority of the spaces are offices and classrooms, this 80 psf live load is a conservative loading.

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Live Loads: from ASCE 7-02

o First floor corridors 100 psf o All other corridors 80 psf o Classrooms 40 psf o Offices 50 psf o Stairs 100 psf o Laboratories 60 psf o Lobbies 100 psf o Balconies 100 psf o Storage 125 psf

Snow Loads - Even though a flat roof snow load of 21 psf was

calculated using ASCE 7-02, 30 psf has been applied to each roof to be conservative. 30 psf is the most commonly used snow load in Northeastern Pennsylvania.

Snow Loads: from ASCE 7-02

o Ground snow 30 psf o Flat roof snow 21 psf

Wind Loads - Wind loads for the lateral system design and analysis were

calculated in RAM Frame using ASCE 7-95. I did not use ASCE 7-02 because the version of RAM Frame available to me is somewhat outdated. RAM Frame calculated ten different wind loading cases, considering wind pressures from different directions as well as unbalanced wind pressures.

RAM Frame distributes the wind forces to the lateral force resisting elements using the relative stiffness method. The relative stiffness method takes into account the stiffness of each individual frame and distributes a larger portion of the total lateral load to stiffer elements than it does to elements that are not as stiff. This method is preferred for L-shaped buildings like this one to ensure that the lateral forces are properly distributed and that smaller elements are not overloaded.

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FNS (k) FEW (k)Roof 12.22 14.44Fi 21. 22.fth Floor 50 88Fourth Floor 20.52 21.69Third Floor 21.68 19.86Second Floor 22.49 18.32Total 98.42 97.19

Wind Load: Maximum Story Forces from RAM Frame

Table 1 Maximum wind load story forces

Seismic Loads - Seismic loads were also calculated in RAM Frame using ASCE 7-95. RAM Frame calculated four seismic loading cases, considering seismic forces from different directions and with eccentricities. Just like the wind forces, the seismic forces have been distributed to the structure using the relative stiffness method.

Seismic Load:

o Total building weight 5690 kips o Base shear

• N-S direction 246.7 kips • E-W direction 284.5 kips

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Lateral System – Reinforced Concrete Shear Walls

Advantages – Moment resisting connections are very expensive compared to connections that only resist shear. Since Brennan Hall’s lateral system consists of multiple moment frames, considerable time and money on both the design and construction sides could possibly be saved by eliminating most, if not all, of the moment connections. Therefore, it would be advantageous to develop a new lateral system that will transfer lateral loads into the ground without employing connections designed to resist moment. However, such systems require diagonal braces or shear walls which cannot be easily concealed in the current floor layouts.

The senior thesis project is an opportunity to showcase strengths in design and analysis and to explore topics that are of interest to a student or are not extensively covered in classes. There is no extensive coverage of lateral force resisting systems in the AE department’s curriculum. Brennan Hall has already provided me with the opportunity to study moment frames through existing conditions reports, and now through my lateral system design, I am studying two other major lateral systems; steel braced frames, and reinforced concrete shear walls.

Proposed Solution – Rather than arbitrarily selecting either braced

frames or shear walls, I conducted some preliminary investigations of each system to determine which I thought would be best.

With each system it was difficult to locate spaces where a brace or wall would not disturb the architectural layout of the building. As a result, when I began placing diagonally braced frames, they were few and far between and generally tall and thin (see Figure 1 at right). Each of these narrow frames received a large portion of the total lateral load and

Figure 1 RAM model of Brennan Hall with braced frame trial.

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performed poorly in drift analysis.

Another difficultly with the braced frame system was caused by the architectural arrangement from floor to floor. In a couple of instances, it was actually fairly simple to find a few good locations for braced frames that worked rather well for the first three floors. However, these locations would require a braced frame to run down the middle of a hallway or conference room on the fourth and fifth floors (see Figure 2 below). Similarly, areas well suited for a braced frame on the upper two floors would have required that frames divide classrooms practically in half on the lower floors. Placing braced frames in different locations on different floors and requiring the floor diaphragm to transfer these high loads from frame to frame only seemed to complicate what I had thought would be a simple system to implement. It seemed to me that there had to be a better way to resist the lateral loads imposed upon Brennan Hall without resorting to the expensive connections used in moment frames. Starting fresh, I found new places where I could construct reinforced concrete shear walls. Since it had been so difficult to find locations for braced frames in the interior of the building, I focused my attention primarily to the perimeter of the structure for placing shear walls. Initially, I placed shear walls only at opposing corners of the building (see Figure 3 at right). After running an analysis of the structure in RAM Frame, I realized that my shear walls were so rigid that drift was not going to be a problem. This realization,

Figure 2 Second floor and roof framing plans for braced frame trial. Braced frames are highlighted in red.

Figure 3 Roof framing plan for shear wall trial. Shear walls are highlighted in red.

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coupled with the simplicity of the structural layout that I was able to achieve, led me to choose to pursue reinforced concrete shear walls for my lateral force resisting system.

Figure 4 Diagrams showing how loads on a wall create moments about the toe of the wall footing.

Shear Wall Design – As I mentioned, the first thing I realized from my RAM Frame analysis was that drift would not be a concern as the initial shear wall layout was sufficiently rigid. However, after sorting through the analysis results for a while, it became evident that since there was so much load spread over so few walls, overturning was a significant problem.

I chose to deal with this overturning problem in three ways; add additional shear walls in order to reduce the load and overturning moment on each wall, increase the thickness of the walls to make them more massive and increase the resisting moment, and increase the footing sizes for each wall in order to increase the resisting moment. Figure 4, below, illustrates how story shears create overturning moments about the toe of the wall footing and how these moments are resisted by moments created by the weight of the shear wall and the footing. First, I added two additional shear walls, placing them in the interior of the building (see walls 5 and 6 in Figure 5a below). These walls extend straight up through the first and second floors before cutting back to shorter lengths for the third and fourth floors as shown in Figure 5b, below. The cut backs of the wall lengths are caused by some of the same architectural constraints that affected the braced frame trial layout. Because of these constraints and because the lateral loads drop off somewhat after the fifth floor level, these additional shear walls only extend up four floors.

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There is more than one accepted method for designing shear and flexural reinforcement for concrete shear walls. I chose to design each shear wall as if it were a deep cantilever beam. In normally proportioned beams, flexural stresses are assumed to be linear through the cross section of the beam. However, in deep beams, high shear stresses cause significant warping of the cross section. This results in a non-linear stress distribution through the depth of the beam. Tests have confirmed theories that the same methods employed in finding flexural strength in normally proportioned beams can be applied to deep beams with sufficient accuracy. Therefore, the flexural reinforcement in shear walls can be designed just as the flexural reinforcement is designed for normally proportioned cantilever beams. Since lateral loads of the same magnitude may act in either direction, the same flexural reinforcement will be placed in both ends of each shear wall. Due to their great depth, diagonal cracking in deep beams generally occurs at an angle greater than 45°. Because of this, vertical stirrups, while still important, are less effective than horizontal web steel which would be oriented more nearly perpendicular to the cracks. Not only do these horizontal bars improve shear transfer by aggregate interlock, but they also improve shear transfer by dowel action. Since a shear wall is a deep beam turned on end, these reinforcing bars become the vertical web reinforcing in this application. Using these design procedures and shear and moment output from a RAM Frame analysis, I designed horizontal and vertical web reinforcing, as well as tensile reinforcement to be placed at both ends of each wall (see Appendix B “Sample Calculations”). Since four of the shear walls are located on the perimeter of the building, they also needed to be designed to resist bending moments caused by wind acting as a surface load. In fact, in these four walls the reinforcement needed to resist the surface load is more critical than the vertical web reinforcing needed for the wall shear. These shear walls are so massive that most of the steel reinforcement was governed by minimum steel areas rather than actual strength requirements. Table 3, below, provides a summary of the dimensions and reinforcement for each shear wall.

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Roof 12 31 14 366 360.73 25.77 (2) #3@6" (2) #3@12" (8) #9 #5 @ 12" #5 @ 12" N/A5 12 31 14 366 674.49 22.41 (2) #3@6" (2) #3@12" (8) #9 #5 @ 12" #5 @ 12" N/A4 12 31 14 366 1454.57 55.72 (2) #3@6" (2) #3@12" (8) #9 #5 @ 12" #5 @ 12" N/A3 12 31 14 366 2350.60 64.00 (2) #3@6" (2) #3@12" (8) #9 #5 @ 12" #5 @ 12" N/A2 12 31 14 366 3808.09 104.11 (2) #3@6" (2) #3@12" (8) #9 #5 @ 12" #5 @ 12" N/A

Roof 12 13 14 150 113.47 8.11 (2) #3@6" (2) #3@12" (6) #7 #5 @ 12" #5 @ 12" N/A5 12 13 14 150 228.07 8.19 (2) #3@6" (2) #3@12" (6) #7 #5 @ 12" #5 @ 12" N/A4 12 13 14 150 608.02 27.14 (2) #3@6" (2) #3@12" (6) #7 #5 @ 12" #5 @ 12" N/A3 12 13 14 150 556.24 3.70 (2) #3@6" (2) #3@12" (6) #7 #5 @ 12" #5 @ 12" N/A2 12 13 14 150 1211.14 46.78 (2) #3@6" (2) #3@12" (6) #7 #5 @ 12" #5 @ 12" N/A

Roof 12 41 14 486 564.15 32.42 (2) #3@6" (2) #3@12" (10) #10 #5 @ 12" #5 @ 12" N/A5 12 41 14 486 1471.41 62.86 (2) #3@6" (2) #3@12" (10) #10 #5 @ 12" #5 @ 12" N/A4 12 41 14 486 2739.42 98.19 (2) #3@6" (2) #3@12" (10) #10 #5 @ 12" #5 @ 12" N/A3 12 41 14 486 3593.11 79.46 (2) #3@6" (2) #3@12" (10) #10 #5 @ 12" #5 @ 12" N/A2 12 41 14 486 4995.58 124.78 (2) #3@6" (2) #3@12" (10) #10 #5 @ 12" #5 @ 12" N/A

Roof 12 13 14 150 157.74 15.94 (2) #3@6" (2) #3@12" (6) #7 #5 @ 12" #5 @ 12" N/A5 12 13 14 150 187.62 8.64 (2) #3@6" (2) #3@12" (6) #7 #5 @ 12" #5 @ 12" N/A4 12 13 14 150 384.59 27.21 (2) #3@6" (2) #3@12" (6) #7 #5 @ 12" #5 @ 12" N/A3 12 13 14 150 453.55 20.54 (2) #3@6" (2) #3@12" (6) #7 #5 @ 12" #5 @ 12" N/A2 12 13 14 150 879.25 51.17 (2) #3@6" (2) #3@12" (6) #7 #5 @ 12" #5 @ 12" N/A5 12 33.5 14 396 1769.06 138.59 (2) #3@6" (2) #3@12" (8) #104 12 33.5 14 396 3901.29 178.69 (2) #3@6" (2) #3@12" (8) #103 12 49.17 14 584 3929.75 248.58 (2) #3@6" (2) #3@12" (10) #102 12 49.17 14 584 4265.37 233.47 (2) #3@6" (2) #3@12" (10) #105 12 19 14 222 1144.77 105.15 (2) #3@6" (2) #3@12" (8) #74 12 19 14 222 2489.67 144.75 (2) #3@6" (2) #3@12" (8) #73 12 40.5 14 480 2613.24 273.61 (2) #3@6" (2) #3@12" (10) #102 12 40.5 14 480 3128.11 227.42 (2) #3@6" (2) #3@12" (10) #10

Lateral Load Resisting Design Area Load Resisting Design

1

6

2

3

4

5

Figure 6a shows the cross-section of shear wall 2 and shear wall 4. These are the smallest and most lightly reinforced shear walls in the structure. The horizontal and vertical web reinforcing is common to all of the shear walls, except for the interior walls (walls 5 and 6) which have less vertical web reinforcing since they do not have to resist surface wind loads. The

Table 3 Summary of dimensions and reinforcement for each shear wall at each level. Walls 5 and 6 are interior walls and therefore were not designed to resist area loads.

Figure 6a Cross-section of shear walls 2 and 4.

Figure 6b Cross-section of shear wall 3.

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cross-section for shear wall 3 is illustrated in Figure 6b above. Since wall 3 is so large, it draws a larger portion of the building shear forces. Because of this, wall 3 is one of the most heavily reinforced elements in the structure. At this juncture, it is difficult to fully judge the success of this reinforced concrete shear wall structure from a material and construction cost standpoint. This topic will be examined in detail in the Scheduling/Cost Breadth Study section of this report. However, considering that this is an educational design and analysis project, I am now in a position to evaluate this structure from that standpoint. Reinforced concrete shear walls are not a topic that is given much attention in our curriculum. In part, my decision to pursue shear walls instead of braced frames was based on my presumption that I would learn more about a somewhat unfamiliar topic. As a result, I have learned a method for the design of reinforced concrete shear walls. I have also explored factors affecting the design of shear walls as a structural system and some methods to overcome problems like overturning.

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Gravity System – Open Web Steel Joists

Advantages/Concerns – Open web steel joists, when configured properly, can be an efficient alternative to wide flange steel infill beams. Reasonably spaced joists can carry loads comparable to wide flange beams over spans greater than 30 or 40 feet. While multiple joists are needed to carry the same load that one steel beam can handle, their light weight allows for a structure of much greater efficiency. Since joists are more closely spaced than steel beams, a thinner deck can be used to span between them, further reducing the weight of the structure. Such dead load reductions can even result in smaller girders, columns, and even spread footings.

However, there are certain concerns introduced with open web steel joists, namely fire protection and floor vibrations. In Brennan Hall, spray-applied cementitious fireproofing was used on the structural steel to help the structure achieve its required fire rating. It can be difficult to adhere this fireproofing to open web joists because the web members are narrow. Vibrations also become an issue as the floor is excited by the movement of occupants. This is more of a problem for steel joists than for steel beams because of the thinner members and reduced mass of the joists.

Figure 7 Plan view of the largest bay in Brennan Hall. It measures nearly 35’ x 30.5’. Steel joists are shown spanning horizontally.

Proposed Solution – The floor plan for Brennan Hall features many spaces where members which can span over 30 feet are needed. For longer spans, open web steel joists are often a good alternative because they have a significantly higher strength to weight ratio than wide flange steel beams. Open web steel joists work best when closely spaced and supporting a thin deck.

I used the RAM Manager beam design module to size steel joists and wide flange steel girders. In order to use the system most efficiently, I used a two and a half inch thick, normal weight concrete deck and a joist spacing of 30 inches (see Figure 7 at right).

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Figure 8 Fourth floor framing plan. Blow-up details illustrate typical framing members.

Figure 8 shows a typical floor framing layout. There are only slight variations in the framing layout from floor to floor. For steel design, it is typically more economical to have infill beams or joists span across the longer dimension of a bay and the girders span across the shorter dimension. While this would make the beams or joists larger, it would allow for the already larger girders to be smaller, resulting in a reduced load and a reduced span. Generally, this makes the whole system more economical. To address this, I divided the floor into two sections, orienting the joists in one section perpendicular to the joists in the other section. In this way, I have been able to span the open web joists in the long direction in most bays.

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The concrete slab consists of normal weight concrete, metal form deck, and welded wire fabric. Steel joist sizes range from a 10K1 in some of the small infill areas to a 28K9 in the largest bays in the building. Relatively small members, such as W12x16 girders frame the smaller areas, while W30x99 girders carry some of the larger floor loads.

Figure 9 Diagram of UL Fire Resistance Directory Design No. G708.

Fire Protection – As I briefly discussed earlier, open web steel joist systems are difficult to fireproof. The spray-applied fireproofing currently in use does not easily adhere to the narrow web members in these joists. Therefore, in order to protect these systems, a fire rated ceiling assembly must be selected that either does or does not rely on steel fireproofing materials. The most notable place to look for such an assembly is the UL Fire Resistance Directo y. r

To achieve the two hour fire rating that I need for Brennan Hall, I found design no. G708 (see Figure 9 below). The numbers in Figure 9 correspond to the following:

1) Normal weight aggregate concrete - 150 pcf, 3500 psi compressive strength

2) Welded wire fabric – 6x6 – 8/8 SWG 3) Steel form units – 2 ½ inch pitch, ½ inch depth of corrugations 4) Steel Joist 5) Spray-applied fire resistive materials 6) Metal lath

This particular assembly does use spray-applied fireproofing. The issue of getting the fireproofing to adhere to the joists is taken care of using metal lath. The metal lath is attached to the open web joists with steel wire. When the fireproofing is sprayed on, it adheres to the metal lath, allowing

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the fireproofing material to build up to its required thickness. Required thicknesses of fireproofing for this assembly are as follows:

o Metal form deck ½ inch o Steel girder 1 inch o Steel joist 1 ½ inch

Floor Vibrations – While being light-weight members make them more

desirable from an efficiency standpoint, being light-weight also makes steel joists more susceptible to vibration. Wide flange beams are more massive and more rigid than joists and therefore perform better when excited by human activity. Since occupant comfort is such an important concern in office buildings, any proposed steel joist floor framing system should be checked for satisfactory performance.

To evaluate my framing system, I conducted a walking excitation check from AISC’s Design Guide 11. For floor vibrations, shorter members are relatively stiffer than longer ones and therefore perform better. Instead of running multiple evaluations, I examined the largest bay in the building (see Figure 7 above), my worst case scenario. If this bay is proven satisfactory, then the remainder of the floor ought to perform satisfactorily as well. In order to perform the analysis, transformed joist properties must be found. Because of the limited properties listed in joist tables, a joist section neutral axis must be calculated, as well as a joist chord area and moment of inertia. Joist and girder mode properties are then calculated and combined to find a combined mode frequency. This frequency is used, along with tabulated data, to determine an acceleration limit. For the bay I analyzed, I found an acceleration of 0.43%g, which is less than the 0.5%g acceleration limit for office buildings (see Appendix B “Sample Calculations”). There is an additional evaluation for floor stiffness for floor systems with a frequency greater than 9 Hz. However, since my frequency is less than 9 Hz, this check is not needed. Spaced closely together while supporting thin floor slabs, open web steel joist floor systems provide a more efficient alternative to floor systems with wide flange steel beams. The system I have designed passes the two main obstacles to steel joist floor framing; fireproofing, and floor vibrations. A ceiling assembly that suits the design requirements for Brennan Hall’s framing layout and is fire rated for two hours has been selected. The floor system also meets walking excitation criteria.

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Scheduling/Cost Breadth Study One of the goals for my lateral system depth study was to develop a lateral force resisting system that would cost less than the moment resisting frames employed in Brennan Hall. Partially for educational reasons, I chose to design reinforced concrete shear walls. In this breadth study, I examine both material and construction costs. To ascertain additional construction costs, scheduling and construction sequencing are considered. Once these cost figures are tallied, I can determine the appropriateness of the reinforced concrete shear walls.

Material Costs There are several material costs affected by this lateral system change. I had to determine the amount of concrete the new shear walls require. Since many of the existing spread footings are replaced by large wall footings, the volume of the footings being removed and the volume of the footings being added had to be calculated. Also, sections of the steel frame (beams, columns, and all moment connections) supplanted by the shear walls are accounted for. I obtained typical material costs from Andrew Shedlock of Sordoni Construction. Mr. Shedlock was the construction project manager for Brennan Hall. Some of these costs are summarized below.

• Cost of 3500 psi concrete (wall footings) $57/cubic yard • Cost of 4000 psi concrete (shear walls) $62/cubic yard • Cost of moment connections $280/connection • Cost of shear connections $70/connection • Cost of steel members $425/ton

Concrete volumes for the footings and the shear walls were calculated from the dimensions in Tables 2 & 3. The number of moment connections replaced by shear connections, the number of, and sizes of, steel beams and columns removed, and the amount of concrete from spread footings being removed were all determined from Brennan Hall’s structural drawings. The following tables summarize the material cost data.

Frame thk (in) Avg lw (ft) hw (ft) vw (ft3) vw (CY) Cost ($/CY) Cost ($)1 12 31 14 434 16.07 62 996.592 12 13 14 182 6.74 62 417.933 12 41 14 574 21.26 62 1318.074 12 13 14 182 6.74 62 417.935 12 41.33 14 578.62 21.43 62 1328.686 12 29.75 14 416.5 15.43 62 956.41

Total Cost ($) 5435.61

Table 4 Calculation summary table for material costs of reinforced concrete shear walls.

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Table 5 (Above) Calculation summary table for material costs for concrete wall footings added and concrete spread footings removed. For footing designations and locations, see Appendix A “Foundation Plan.”

Table 6 (Right) Calculation summary table for material costs for shear connections replacing moment connections and steel beams & columns removed.

C

BeW

WW

WWWWWWW

onnections Cost ($/CY) Cost ($)Moment 280 -67200.00Shear 70 16800.00

ams Qty Wt. (plf) length (ft) Wt. (lb) Wt. (Tons) Cost ($/Ton) Cost ($)16x26 1 26 8.5 221 0.11 425 -46.96

W16x26 5 26 11 1430 0.72 425 -303.8816x26 1 26 13 338 0.17 425 -71.8316x26 4 26 15.67 1629.68 0.81 425 -346.31

W16x26 5 26 16.5 2145 1.07 425 -455.8116x26 1 26 18.5 481 0.24 425 -102.2116x26 1 26 21.5 559 0.28 425 -118.7918x35 3 35 4 420 0.21 425 -89.2518x35 4 35 13 1820 0.91 425 -386.7518x35 4 35 19 2660 1.33 425 -565.2518x35 5 5 51 639.6318x35 5 7 47 200.81

W18x40 3 40 8.5 1020 0.51 425 -216.75W18x40 1 40 13 520 0.26 425 -110.50W18x40 4 40 18.5 2960 1.48 425 -629.00W18x40 1 40 21.5 860 0.43 425 -182.75W18x50 4 50 13 2600 1.30 425 -552.50W21x50 1 50 8.5 425 0.21 425 -90.31W21x50 1 50 21.5 1075 0.54 425 -228.44W21x62 1 62 21.5 1333 0.67 425 -283.26W24x55 1 55 4 220 0.11 425 -46.75W24x68 1 68 21.5 1462 0.73 425 -310.68W24x76 1 76 40.5 3078 1.54 425 -654.08W27x84 1 84 15.67 1316.28 0.66 425 -279.71W27x84 2 84 27 4536 2.27 425 -963.90W27x94 1 94 27 2538 1.27 425 -539.33

ColumnsW8x24 3 24 14 1008 0.50 425 -214.20W8x31 8 31 14 3472 1.74 425 -737.80W8x40 10 40 14 5600 2.80 425 -1190.00W8x48 2 48 14 1344 0.67 425 -285.60W8x58 4 58 14 3248 1.62 425 -690.20W8x67 4 67 14 3752 1.88 425 -797.30W12x45 3 45 14 1890 0.95 425 -401.63

12x50 3 50 14 2100 1.05 425 -446.2512x53 2 53 14 1484 0.74 425 -315.3512x72 4 72 14 4032 2.02 425 -856.8012x87 2 87 14 2436 1.22 425 -517.65

W14x82 3 82 14 3444 1.72 425 -731.85W14x176 2 176 14 4928 2.46 425 -1047.20

Total Cost ($

4 3 21. 3010 1. 425 -1 3 2 945 0. 425 -

WWWW

) -67047.24

Qty240240

New Ftgs thk (ft) width (ft) length (ft) vw (ft3) vw (CY) Cost ($/CY) Cost ($)1 5 12 43 2580 95.56 59 5637.782 5 12 25 1500 55.56 59 3277.783 5 12 53 2400 88.89 59 5244.444 5 14 30 2100 77.78 59 4588.895 6 16 64 4664.16 172.75 59 10192.056 6 16 60 5760 213.33 59 12586.67

emoved FtgsF50 1.33 5 5 33.25 1.23 59 -72.66F60 1.67 6 6 60.12 2.23 59 -131.37F66 1.83 6.5 6.5 77.3175 2.86 59 -168.95F70 1.83 7 7 89.67 3.32 59 -195.95

(3) F76 2 7.5 7.5 337.5 12.50 59 -737.50F80 2.17 8 8 138.88 5.14 59 -303.48

(3) F86 2.17 8.5 8.5 470.3475 17.42 59 -1027.80F120 2.67 12 12 384.48 14.24 59 -840.16F136 2.17 13.5 13.5 395.4825 14.65 59 -864.20F5680 1.5 5.6 8 67.2 2.49 59 -146.84

Total Cost ($) 37038.70

R

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Construction Schedule Material costs only tell half of the story. Any additional costs due to extra equipment and personnel on site, as well as costs due to changes in the duration of construction activities, also factor into the entire project cost scheme. Before these costs can be determined, a construction sequence must be established.

WeekDay S M T W R F S S M T W R F S S M T W R F S S M T W R F S S M T W R F S S M T W R F S

4: Oct. 31-Nov. 6 5: Nov. 7-13 6: Nov. 14-20

Foundation System

1: Oct. 10-16 2: Oct. 17-23 3: Oct. 24-30

Level 1 Walls

Form 1 & 2 - 1 Crew

Pour 1 & 2

Form 3 & 4 - 1 Crew

Pour 3 & 4

Form 5 & 6 - 2 Crews

Pour 5 & 6

Level 2 Walls

Form 1 & 2 - 1 Crew

Pour 1 & 2

Form 3 & 4 - 1 Crew

Pour 3 & 4


Pour 5 & 6

Level 3 Walls

Form 1 & 2 - 1 Crew

Pour 1 & 2

Form 3 & 4 - 1 Crew

Pour 3 & 4


Pour 5 & 6

Level 4 Walls

Form 1 & 2 - 1 Crew

Pour 1 & 2

Form 3 & 4 - 1 Crew

Pour 3 & 4


Pour 5 & 6

Level 5 Walls

Form 1 & 2 - 1 Crew

Pour 1 & 2

Form 3 & 4 - 1 Crew

Pour 3 & 4

Steel Delivery

Steel Erection

Figure 10 Detailed construction sequence for erection of reinforced concrete shear walls.

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Mr. Shedlock and some of the senior thesis practitioner mentors provided me with all of the relevant construction duration and cost information. Some of this information is summarized below.

• Forming shear walls o Four carpenters $38/hour each o One carpenter foreman $41/hour o Two laborers $31/hour each o One laborer foreman $43/hour

• Placing & Finishing Concrete o Concrete pump $1200/day o Four man crew $39/hour each

• Steel Erection o Beams & Columns 50 pieces/day o Crane w/five man crew $5000/day

The detailed schedule in Figure 10, above, utilizes two, six man crews (four carpenters and two laborers) building the formwork for the reinforced concrete shear walls. Since formwork can be built one story high for a length of 40 feet in about two days, one crew can construct the formwork for the first level of walls 1 and 2 (see Figure 5a and Table 3) in three days. Similarly, the first level of walls 3 and 4 can be constructed by the other crew in three days. After these forms have been completed, the formwork for the first level of walls 5 and 6 are built. These forms only take two days to complete because each crew builds a wall. As sections of the formwork are completed, the concrete placing and finishing crew begins pouring the concrete walls. In general, this crew can pour one or two walls per day. A test break is done 72 hours after the concrete is poured. If the concrete has reached 50% of its yield strength by the time of the break, the formwork can be stripped and reassembled for the next level. This process is repeated four more times for walls 1 through 4 and three more times for walls 5 and 6. Even though the new wall footings require more excavation and more concrete, they do not significantly affect the duration of either the excavation or foundation system activities. This is because it is nearly as quick and easy for the excavator to dig a somewhat bigger hole and for the concrete crew to pour a little extra concrete. While the duration remains unchanged, the sequencing of the footing construction must be modified so as to complete the shear wall footings, and any spread footings closely surrounding them, first. This will allow the shear wall construction to begin before the completion of, and finish at about the same time as, the foundation construction. Accomplishing this will avoid any delays of steel erection activities.

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In addition to reducing material costs, steel erection time is also saved by removing the steel members that are supplanted by the reinforced concrete shear walls. Just over one hundred steel beams and columns are being removed (see Table 8 below). Assuming 50 pieces of steel can be erected per day, the steel erection duration can be reduced two days. Moment resisting connections are not only expensive; they also take extra time to assemble. By eliminating all moment connections, I estimate another two construction days can be saved. All told, the steel erection duration can be shortened four days. An overview of the construction schedule for Brennan Hall’s structural system is illustrated in Figure 11, below.

YearMonth

12/17

1999July August September October November December

Foundation System

Shear Wall Construction

8/2 11/15

10/11 11/12

Original ScheduleSchedule with Shear Walls

Steel Delivery12/13

Steel Erection

11/15

11/15

Figure 11 Structural system construction schedule. Using the durations from the detailed shear wall (Figure 10 above) and structural system (Figure 11 above) schedules along with the cost information previously listed, construction costs are calculated and tabulated in Tables 7 & 8, below.

Qty Duration (hr or day) Cost ($/hr) Cost ($/day) Cost ($)Formwork Carpenters 8 184 38 55936

Carp. Foreman 1 184 41 7544Laborers 4 184 31 22816

Labor Forman 1 184 43 7912Pump 1 22 1200 26400Crew 4 176 39 27456

Total Cost ($) 148064

Activity

(2 Crews)

Place & Finish

Table 7 Calculation summary table for construction costs for forming and placing reinforced concrete shear walls.

Qty Duration (day) Cost ($/day) Cost ($)

Bms & Cols 107 2 5000 -10000Connections 240 2 5000 -10000

Total Cost ($) -20000

ActivityErection

Table 8 Calculation summary table for construction costs for erecting steel beams & columns and creating moment connections.

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Final Cost Figures The cost figures from Tables 4 through 8 are summarized in Table 9, below. Considering material and construction costs, the reinforced concrete shear wall system costs $103,500 more than the existing moment frame system. While this may seem like a large overage, keep in mind that the entire project cost for Brennan Hall was $12,350,000. Therefore, this reinforced concrete shear wall system increases the entire project cost by less than 0.9%.

Cost ($)Shear Walls 5435.61

Footings 37038.70Steel -67047.24

Concrete 148064Steel -20000

Total Cost ($) 103491.07Project Cost ($) 12350000

Percent Change (%) 0.84

ItemMaterials

Construction

Table 9 Calculation summary table for material and construction costs. Increase in project cost and percent increase in project cost also listed.

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Wireless LAN Breadth Study

Advantages Designed to showcase information technology throughout the building, Brennan Hall continues to be a leader in technology. However, when it was built, wireless network solutions were not as mature as they are now. Wireless local area networks (WLAN) are popping up in office buildings everywhere because of the multitude of advantages and services these networks provide for their users. Wireless networks are more flexible than their wired counterparts. They provide continuous, cable free access to any connected networks. E-mail and the internet can be accessed from anywhere within range of a wireless access point. They can act as hot spots for students with laptops, allowing them to access course information or student accounts. A WLAN is also cost effective. Initial construction costs would be lowered since wireless networks require a minimum amount of wires and cables to be installed throughout the building. Before, Ethernet cables would need to be run to each and every office, now cables only need to run to the locations of wireless access points. Overhead costs are reduced since new cables no longer need installed to accommodate moves and extensions to networks. These networks are also easily expandable. Once a network is in place in one building, it is easy to add other buildings. For a building like Brennan Hall, a WLAN seems like a great solution for their networking needs. There are three standards specified by the IEEE; 802.11b, 802.11a, and 802.11g. Each standard has its own advantages and disadvantages. My design calls for the 802.11a standard as specified by the IEEE. With all of the faculty, staff, and students moving in and out of the building, I anticipate periods when many users will be accessing the network at the same time. 802.11a can handle 64 users per access point, twice as many as the other standards. This will require fewer access points and less cable. Standards 802.11b and 802.11g operate at frequencies in the same range as cellular phones and microwave ovens. Because of faculty lounges and cellular phone use in the building, 802.11a, which operates at a higher frequency, offers a lower possibility of interference from these devices. This network consists of three virtual networks; one for university administrators, one for faculty, and one for students. All of these networks can be accessed inside of Brennan Hall as well as on the lawn in front of the building. A point to point bridge is used so that the network can be accessed in the adjacent Mulberry Street Apartments dormitory that was constructed at the same time

27



Brennan Hall was. Other buildings on campus can be connected to the network in the same way. In addition to the access points, wired devices, such as computers, printers, and desktop IP phones (which I will discuss later) will be located in secretary and reception areas. These devices are all located in areas where the mobility that wireless products provide is simply not needed and the conventional equipment is still more than adequate.

Access Points Wireless access points allow any device equipped with a wireless PC card to access information on the network. They are connected via Ethernet cables to the building’s wired backbone. Access to the network is limited by the number of users trying to connect to the network and the distance of the user from an access point. Each standard 802.11a access point can accommodate up to 64 users. In order to make sure that occupants are not denied access to the network because all access points are full, I have included enough access points to ensure that there is extra capacity. More capacity can be added in the future by stacking additional access points in the same location. The range of an 802.11a wireless access point is about 100 feet. However, this range is somewhat reduced by transmission through walls and floors. Since Brennan Hall’s building footprint is close to 140 feet square, the range is not much of a concern. The number of access points needed will therefore be governed by the maximum number of users estimated. To determine how many wireless access points are needed in Brennan Hall, I began by estimating how many computers may be used in each office and classroom on each floor of the building. I accounted for a few extra users on each floor to allow for students using laptop computers in quiet study and lounge areas and to provide for some extra capacity. Knowing the demand for each floor, I was able to determine the number of access points needed for each floor (see Table 10 below). The first floor estimate for wireless computers exceeds the number of users that three access points can handle. However, that estimate assumes that every student in each classroom will be trying to access the network at the same time. Since this is highly unlikely, I felt no need to design for full usage. Conversely, one access point should be able to handle all of the users on the fourth floor, but I wanted the extra capacity should I have underestimated the demand from the offices and conference rooms on that floor.

First Floor Second Floor Auditorium Third Floor Fourth Floor Fifth Floor TotalWireless Computers 210 178 150 69 34 95 736Wireless Access Points 3 3 2 2 2 2 14

Table 10 Estimated number of wireless computers and access points per floor. Figure 12, below, shows the locations of wireless access points on each floor. Server closets are located adjacent to the case rooms on the first and second

28


floors. Since all the wiring will originate from these two rooms, I tried to locate access points and any wired devices (secretary computers, desktop IP phones, printers, etc.) as close as practical to these server closets.

P

PP

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Architectura

APSC

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IP Phones Wiring is expensive. Not just in terms of first time material and installation costs, but even more so when added for additional phone lines or replaced as it wears or becomes obsolete. By using a wireless network I have greatly reduced the amount of Ethernet cable needed. Taking further advantage of the network, I can eliminate standard phone lines throughout the building. Internet protocol phones work through the data network, eliminating the need for standard telephone service. They offer all the same features that standard business telephones provide. Companies like Cisco Systems market these phones in various forms, including; PC based phones, desktop models, and wireless phones.

Figure 13 Screenshot of Cisco IP SoftPhone, from: www.cisco.com.

Cisco offers software that allows any personal computer to be used as an IP phone. Once this software is installed, all that is needed are speakers and a microphone and phone calls can be made from any machine within the building. All standard telephone features are included. Phonebooks are easy to setup and use. An individual’s extension follows his/her user account so that he/she can make or receive calls from any networked computer. With this software, teleconferencing is quick and easy, and can be done from any computer. Individuals can be added to a conference simply by dragging and dropping directory entries. Applications running on one computer may also be viewed by others participating in the conference.

Figure 14 Cisco IP Phone 7940G, from: www.cisco.com.

Many companies, Cisco included, produce IP phones in desktop models. These phones function exactly the same as standard telephones, except that they send information over the internet instead of through phone lines. However, even very basic models can be rather expensive. Because of this expense, the desktop models are only located in secretary and reception areas. Secretaries are likely to spend much of the day making phone calls and may prefer using a more conventional phone. The SoftPhone software will be installed on every computer in the building. Since other faculty and staff do not rely on their phones as much, this provides a more cost

30



effective solution for providing each individual with phone service. I have also included five wireless IP phones for the use of physical plant employees when working in Brennan Hall. Figure 15 Cisco Wireless IP Phone

7920, from: www.cisco.com.

Interactive Whiteboards In keeping up with technology in the classroom, I have placed interactive whiteboards in every classroom and conference room in Brennan Hall. Replacing overhead projectors, projector screens, and black/whiteboards, interactive whiteboards are a powerful teaching tool. Instructors can present class notes on them just like normal whiteboards and then save the notes on the computer to be printed or posted to a course website. Computer presentations can also be displayed on the interactive whiteboard, eliminating the need for screens and projectors. Changes can be made, and saved, to presentations or notes with “electronic ink.” The interactive whiteboard even has touch screen capabilities for controlling a computer and accessing links on websites.

Figure 16 SMART Board Interactive Whiteboard, from: www.ivci.com.

Figure 17 TANDBERG 6000, from: www.ivci.com.

Video Conferencing With the SoftPhone software on every computer, teleconferencing is already available from anywhere inside Brennan Hall. However, there is a need for video conferencing in the executive conference center. Video conferencing systems from TANDBERG offer built in conferencing with multiple audio and video sites. PC presentations can easily be added to a conference. The system includes dual LCD displays that allow participants to see live PC presentations and the presenter simultaneously.

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Summary and Conclusions

Structural Depth Study – Reinforced Concrete Shear Walls Moment connections are expensive to construct because of the extra material and especially the extra labor that is involved in these connections. My goal in this study was to devise a lateral force resisting system that would be less expensive to build than Brennan Hall’s existing moment frames. I began by conducting preliminary investigations of a steel braced frame system and a reinforced concrete shear wall system. The shear wall system was more rigid than the braced frame system. After making this observation, I decided to pursue the shear walls because they would provide adequate results while requiring fewer frame locations. While reducing the number of frame locations seemed advantageous, it meant that larger portions of the lateral loads were spread to each shear wall. These large loads created overturning problems for each wall. To overcome these overturning moments, I had to add additional shear walls, increase the mass of each shear wall, and increase the mass of each shear wall footing.

Scheduling/Cost Breadth Study To find out whether the reinforced concrete shear wall system reduced the entire project cost, I analyzed the material and construction costs associated with this change in the structural system. I determined quantities of materials being added and materials being removed. Considering material costs alone, the shear wall system saves nearly $25,000. In order to establish construction costs, I began by sequencing the construction of the shear walls. The cost to build the walls was then determined by applying labor and equipment rates. A reduction in the steel erection costs was also calculated in much the same fashion. The construction costs totaled just over $128,000. Therefore, the reinforced concrete shear wall system costs an additional $103,500. It provides no cost savings when compared to the existing moment frame system. However, this increased cost accounts for less than a 0.9% increase in the total project cost.

Based on my scheduling and cost breadth study, the shear wall system actually costs a little more money than the moment frame system. In retrospect, shear walls probably are not the best lateral force resisting system for Brennan Hall. They would, however, be better suited for buildings with regular and repeating floor plans, with multiple locations where walls extend straight up through the building uninterrupted. In such a building, more shear walls could be employed,

32



reducing the magnitude of the lateral loads on each wall which, in turn, would reduce the overturning moments. Buildings with deep foundation systems, like piles or caissons, would also be better suited to resist the higher overturning moments. On an educational level, the shear wall system was successful. It gave me the opportunity to examine a lateral force resisting system that was largely unfamiliar to me. I also had the chance to explore some of the obstacles and design issues that may stand in the way of such a system.

Structural Depth Study – Open Web Steel Joists In many cases, open web steel joists provide an efficient alternative to steel wide flange infill beams. However, two hurdles generally stand in the way; fire protection and floor vibrations. Because of their narrow web members, steel joists are more susceptible to fire damage. To combat this, I found a two hour fire rated ceiling assembly in the UL Fire Resistance Directory. This assembly uses metal lath to help spray-applied fireproofing adhere to the joist webs. The reduced mass of these joists also makes them prone to floor vibrations. Being fully aware of this, I used AISC’s Design Guide 11 to check the adequacy of my largest floor bay for human activity. Since my “worst case scenario” floor bay performs adequately, the remainder of my floor system should also perform adequately. Having been able to overcome the barriers that usually plague open web steel joist floor framing, this appears to be a most appropriate framing system for Brennan Hall.

Wireless LAN Breadth Study Incorporating wireless technology only seems logical for a leader in technology like Brennan Hall. To meet their information technology needs, I have established a data network consisting of three virtual networks; one for administrative purposes, one for faculty, and one for students. This network operates on the IEEE 802.11a standard, offering a lower possibility of interference. Wireless access points were located throughout the building based on estimates of computer usage. To keep up with, and improve upon, the technology in the building, I have situated IP phones, interactive whiteboards, and sophisticated video conferencing units throughout Brennan Hall’s meeting and instructional spaces. The overall result is an information technology scheme that is more flexible, easy to operate, and takes better advantage of today’s available technology.

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Works Cited American Concrete Institute. Building Code Requirements for Structural Concrete

(ACI 318-02) and Commentary (ACI 318R-02). Farmington Hills: ACI International, 2002.

American Institute of Steel Construction. Manual of Steel Construction; Load and

Resistance Factor Design. 3rd Edition. Chicago: American Institute of Steel Construction, 2001.

American Institute of Steel Construction. Steel Design Guide Series 11; Floor

Vibrations Due to Human Activity. Chicago: American Institute of Steel Construction, 1997.

American Society of Civil Engineers. Minimum Design Loads for Buildings and

Other Structures; SEI/ASCE 7-02. Reston: American Society of Civil Engineers, 2002.

Cisco 7900 Series IP Phones. Cisco Systems. 14 Feb. 2004

< http://www.cisco.com/en/US/products/hw/phones/ps379/index.html>. Cisco IP SoftPhone 1.3. Cisco Systems. 14 Feb. 2004

<http://www.cisco.com/en/US/products/sw/voicesw/ps1860/products_data_sheet09186a0080092436.html>.

Nilson, Arthur H. Design of Concrete Structures. 12th Edition. New York:

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Feb. 2004 <http://www.ivci.com/videoconferencing_smart_board_interactive_whiteboard.html>.

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34



Appendix A

Foundation Plan

A-1



Detail 3

Detail 2

Detail 1

Figure A-1 Existing foundation plan for Brennan Hall. Areas highlighted in green are illustrated in Figures A-2 through A-4, below.

A-2



Figure A-2 (Right) Blow-up

Detail 1 from Figure A-1, above. Footings that are being removed are highlighted in blue. For footing designations, see Table A-1, below.

Figure A-3 (Left) Blow-up Detail 2 from Figure

A-1, above. Footings that are being removed are highlighted in blue. For footing designations, see Table A-1, below.

A-3



Figure A-4 (Left) Blow-up Detail 3 from Figure A-1, above. Footings that are being removed are highlighted in blue. For footing designations, see Table A-1, below.

Table A-1 (Right) Concrete spread footing schedule. For footing locations, see Figures A-1 through A-4, above.

A-4



Appendix B

Sample Calculations

B-1



Calculation spreadsheet used for designing steel reinforcement for reinforced concrete shear walls.

Parametersf'c (psi) 4000 thk (in) 12 Pw (psf) 11.15Fy (ksi) 60 lw (ft) 31Mu (ft-k) 360.73 hw (ft) 14Vu (k) 25.77 d (in) 366

LateralShearVc (k) 555.5489ΦVn (k) 208.3309 > 25.77 if not, reinf. req'd

Vs req'd (k) -521.189s (in) 73.2 < 12 if not, use s=12"s(in) 12

Horiz. WebAv h (in2) -0.2848Av min (in2) 0.36 < -0.2848 if not, use Av min

Av h (in2) 0.44

Vert. WebAv (in2) -5.5213Av min (in2) 0.216 < -5.5213 if not, use Av min

Av (in2) 0.22

TensileAs (in2) 8a (in) 11.76471ΦMn (ft-k) 155570.8 > 360.73 if not, increase As

c (in) 13.84083ρ 0.001821 > 0.0018 if not, increase Asεs 0.076331 > 0.005 if not, decrease As

This spreadsheet is continued on the next page.

B-2



A

B-3

rea Load+Mu (ft-k) 0.198673-Mu (ft-k) 0.21854Vu (k) 0.089758

+ Reinf.As (in2) 0.23a (in) 0.338235d (in) 10.25ΦMn (ft-k) 125.2046 > 0.198673 if not, increase As


- Reinf.As (in2) 0.23a (in) 0.338235d (in) 10.25ΦMn (ft-k) 125.2046 > 0.21854 if not, increase As


ShearVc (k) 18.21472ΦVn (k) 6.83052 > 0.089758 if not, reinf. req'd



Calculation spreadsheet used for sizing concrete wall footings for reinforced concrete shear walls.

Level Shear (k) D (ft)of 0 79 hw (ft) 70 ftg thk (ft) 6 Fallow (ksf) 5

5 138.59 65 lw (ft) 49.17 ftg width (ft) 16 P (k) 385.794 178.69 51 thkw (ft) 1 ftg length (ft) 643 248.58 37 wall wt. (pcf) 145 ftg wt. (pcf) 1452 233.47 23 soil ht. (ft) 3 soil wt. (pcf) 125

MO ft-k) 32688.81 F.S. 1.739463211MR ft-k) 56860.98

Fac al (ksf

Ro ( (

B-4

tu ) 2.112008 < 5



Hand calculations used for open web steel joist floor vibration evaluation.

These calculations are continued on the next page.

B-5




B-6


These calculations are continued on the next page.

B-6



B-7



About the Author

Douglas Wisniewski

Douglas first developed an interest in architectural engineering while taking drafting and architectural drawing courses at the State College Area High School. He enrolled in the College of Engineering at the Pennsylvania State University in the fall of 1999 and is now in his fifth year in the architectural engineering program, structural discipline. He is pursuing a Bachelor of Architectural Engineering degree as well as a Master of Architectural Engineering degree in Penn State’s Integrated BAE/MAE Program. Currently Douglas serves as the Secretary of the Penn State chapter of Phi Alpha Epsilon, the National Architectural Engineering Honor Society; and is a member of the Student Structural Engineering Association, Golden Key International Honour Society, and the National Society of Collegiate Scholars. To supplement his coursework, Douglas worked this past summer with QproQ Engineering, Inc., a structural engineering consulting firm in Wilkes-Barre, Pennsylvania. There, his responsibilities included; determining loads and load paths, sizing structural members, and creating and editing contract drawings and specifications. Douglas successfully completed the Fundamentals of Engineering Exam in April 2003 and will seek professional licensure when he is able. He expects to graduate in December 2004 at which time he will begin working for a structural engineering consulting or architectural engineering firm. For more information regarding this project, please visit my Capstone Project e-Portfolio at:

http://www.arche.psu.edu/thesis/2004/dxw196/

architectural engineering spring 2004 senior thesis · water reheating coils. it is serviced by two...

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