Improving Construction Efficiency: Structural and Mechanical Solutions

1. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield Structural Discipline Senior Thesis Penn State University Spring 2004

2. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield Improvements on Construction Efficiency from a Structural and Mechanical Perspective Senior Thesis Penn State University Spring 2004

3. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield • Presentation Outline • Introduction and Background Information • Discussion of the Problem Statement • Structural Solution - Incorporation of Diagonal Chevron • Bracing • Mechanical Solution - Rooftop Mechanical Penthouse Enclosing Direct • Expansion System • Four-Dimensional Rendering of the Building Showing Sequence of • Construction • Conclusions Senior Thesis Penn State University Spring 2004

4. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield • The Project Team: • Owner – School District of the City of York • Architect – Gilbert Architects (Lancaster, PA) • Construction Manager – The Quandel Group, Inc. (Harrisburg, PA) • Structural Engineer – Baker, Ingram & Associates (Lancaster, PA) • Mechanical/Electrical Engineer – Moore Engineering Company (Lancaster, PA) • Civil/Landscape Architect – Rettew Associates, Inc. (York, PA) • Acoustical Consultant – Metropolitan Acoustics (Philadelphia, PA) Senior Thesis Penn State University Spring 2004

5. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield • General Building Description: • Total Project Size – 450,000 SF • 285,000 SF of Renovations to the Existing Structure • 165,000 SF of New Design (Focus of Research) • Total Height – Approximately 65’ from Finished Grade to Roof • 3 Actual Stories, 4 Levels (Due to Extended Stage Roof) • Total Cost - $41 Million (Half new construction, and Half Renovations) • Dates of Construction – Begun in June, 2003 and is Estimated to Be Completed September 1, 2006 • Delivery Method – Design-Bid-Build with Multiple Prime Contracts with CM Senior Thesis Penn State University Spring 2004

6. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield • Architectural Background: • Project Began as a Typical Renovation Project for the Original 1930’s Structure • Due to Unforeseen Structural Failures During this Design, the Project Team Took a Different Approach • The Designers Wanted to Maintain the Historical Nature of the Building, so They Decided to Reuse the Original Main Entry Facade for the New Addition Senior Thesis Penn State University Spring 2004

7. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield • Structural Background: • Foundation System – Deep Foundation System Consisting of Caissons and Caisson Caps (Necessary Due to Poor Site Conditions) • Gravity System – A Typical Bay Consists of Composite Metal Deck on Wide Flange Steel Beams/Girders with Lightweight Concrete Topping Connecting to Wide Flange Steel Columns • Lateral System – Ordinary Steel Moment Frames Distributed Throughout The Entire Building (chosen due to architectural constraints) Senior Thesis Penn State University Spring 2004

8. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield Overall Plan of the Entire Building: A B F C E D Senior Thesis Penn State University Spring 2004

9. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield Plan of the New Portion (Area E) of the Building: Senior Thesis Penn State University Spring 2004

10. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield Model Showing Layout of the Original Moment Frames: Senior Thesis Penn State University Spring 2004

11. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield • Presentation Outline • Introduction and Background Information • Discussion of the Problem Statement • Structural Solution - Incorporation of Diagonal Chevron • Bracing • Mechanical Solution - Rooftop Mechanical Penthouse Enclosing Direct • Expansion System • Four-Dimensional Rendering of the Building Showing Sequence of • Construction • Conclusions Senior Thesis Penn State University Spring 2004

12. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield In the Construction Industry… Time is Money and Money is Efficiency! Senior Thesis Penn State University Spring 2004

13. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield With this in mind, it is clear that getting a project done in a more timely fashion is crucial to providing a more economic solution for the client. Therefore, the majority of the research done here is based on finding viable alternatives to optimize the construction schedule of the William Penn Senior High School. Senior Thesis Penn State University Spring 2004

14. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield Disadvantages of the use of Steel Moment Frames: Senior Thesis Penn State University Spring 2004

15. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield • Disadvantages of the use of Steel Moment Frames: • Steel Moment Frames are Relatively Expensive to Construct According to Les Barno of the Quandel Group, Moment Connections Can be Classified According to the Following Average Price Categories: • Smaller Connections - $125 each • Larger Connections - $400-$500 each Much greater steel tonnage in a moment frame system, causing a large cost increase in raw material Senior Thesis Penn State University Spring 2004

16. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield • Disadvantages of the use of Steel Moment Frames: • Steel Moment Frames are Relatively Expensive to Construct The Professionals at AISC have Published some Relative Cost Data for the various components of a typical moment connection (assuming one supporting member (girder/column) and two supported members (beams): • 2 shop-welded, single plate shear connections to girder (field bolted) - 1.00 • 2 tee shear connections to girder (shop welded and field bolted) - 1.14 • 2 stiffened PR connections to column (top angle, bottom seat) - 1.50 • 2 web bolted, flange butt welded moment connection - 1.00 • 2 web bolted and flange bolted plate moment connection - 2.00 Senior Thesis Penn State University Spring 2004

17. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield • Disadvantages of the use of Steel Moment Frames: • Steel Moment Frames Take a Long Time to Construct According to Barno, Moment Connections Take Approximately TWICE as Long to Detail as Standard Shear Connections • Erection crew: • 1 ironworker assembling steel on the ground • 2 ironworkers connecting the steel in the air • 1 crane operator • 10 ironworkers performing as detailers • 2 foremen overseeing erection Senior Thesis Penn State University Spring 2004

18. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield • Disadvantages of the use of Steel Moment Frames: • Steel Moment Frames Take a Long Time to Construct With this 16 man crew, it was estimated that the steel erection and detailing would span from September 5, 2003 to April 6, 2004 (about 213 days). However, due to unforeseen delays, the schedule is now being driven by the detailing requirements for the numerous moment connections throughout the building, and the project manager is pushing to acquire additional detailing manpower. Senior Thesis Penn State University Spring 2004

19. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield • Presentation Outline • Introduction and Background Information • Discussion of the Problem Statement • Structural Solution - Incorporation of Diagonal Chevron • Bracing • Mechanical Solution - Rooftop Mechanical Penthouse Enclosing Direct • Expansion System • Four-Dimensional Rendering of the Building Showing Sequence of • Construction • Conclusions Senior Thesis Penn State University Spring 2004

20. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield • Proposed Solution for a More Economical Structure: Senior Thesis Penn State University Spring 2004

21. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield • Advantages of the use of Diagonal Bracing: • Diagonal Braced Frames Are Efficient from a COST Perspective • In a braced frame system, the amount of labor involved in detailing the connections is minimal compared to a moment connection. • According to the literature produced by AISC, a braced frame connection costs roughly 1/3 to 1/4 of the price of a moment connection. Senior Thesis Penn State University Spring 2004

22. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield • Advantages of the use of Diagonal Bracing: • Diagonal Braced Frames Are Efficient from a COST Perspective • $358,875 x 1/3 = $119,625 • SAVINGS = $358,875 - $119,625 = $239,250 • Based on this data, it can be estimated that a total savings of $239,250 can result from choosing diagonal bracing as an alternate system and eliminating all of the moment connections in the structure. • In addition, the reduction in raw material costs will yield substantial savings. Senior Thesis Penn State University Spring 2004

23. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield • Advantages of the use of Diagonal Bracing: • Diagonal Braced Frames Are Efficient from a TIME Perspective • It was stated that shear connections can be detailed in approximately HALF the time that it would take to detail a moment connection. • The original schedule allowed for 213 days (September 5, 2003 to April 6, 2004) to erect and detail all of the structural steel. • Cutting this in half would yield an estimated time of completion of December 24, 2003. • However, due to other construction activities, steel erection may not be exactly cut in half. Senior Thesis Penn State University Spring 2004

24. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield Other Considerations when Using Diagonal Bracing: • Changing the lateral system to distinct frame locations can introduce significant uplift forces in the lower level columns. Senior Thesis Penn State University Spring 2004

25. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield Other Considerations when Using Diagonal Bracing: • To account for this uplift force, the reinforcing cage in the caissons must be extended the full length of the member. • In addition to this, the caisson must be checked to see if it can carry the uplift force by its own weight. • Consider looking at the surface friction and its impact on the resistance to uplift force is recommended. Senior Thesis Penn State University Spring 2004

26. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield Other Considerations when Using Diagonal Bracing: • Examine the implications of installing the diagonal bracing. • As seen here, the original CMU wall lies on the column line, interfering with the desired bracing location. Senior Thesis Penn State University Spring 2004

27. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield Other Considerations when Using Diagonal Bracing: • Consider installing the bracing “tight” against the wall. • However, this may cause excessive block cutting and numerous wall ties on the bracing to ensure lateral stability (labor intensive). • Consider offsetting the wall and/or column line. • Good solution, although the bracing would still be exposed, and would need to be fireproofed somehow. Senior Thesis Penn State University Spring 2004

28. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield Other Considerations when Using Diagonal Bracing: • A better solution would be to form a double CMU wall with the bracing fitted in between them. • This solution would not involve adjusting column center lines. • The CMU walls would provide added fire-resistance for the bracing members. Senior Thesis Penn State University Spring 2004

29. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield Other Considerations when Using Diagonal Bracing: • Although braced frames are very rigid by nature, story deflection is still crucial to control in situations involving expansion joints connecting existing structures to new designs. Senior Thesis Penn State University Spring 2004

30. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield Other Considerations when Using Diagonal Bracing: • The seismic load case, S2, yields a story displacement at the most critical level of 0.41 inches. • Even with the deflection amplification factor of 3.5 specified by ASCE 7-02, the deflection (1.44”) is still less than half of the 3 inch expansion joint, so deflection criteria has been satisfied. Senior Thesis Penn State University Spring 2004

31. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield Other Considerations when Using Diagonal Bracing: • Uniformity of specified shapes is also an important consideration in structural design of any type and can save money in itself. • The bracing design was reduced to the four HSS shapes listed here. Senior Thesis Penn State University Spring 2004

32. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield • Presentation Outline • Introduction and Background Information • Discussion of the Problem Statement • Structural Solution - Incorporation of Diagonal Chevron • Bracing • Mechanical Solution - Rooftop Mechanical Penthouse Enclosing Direct • Expansion System • Four-Dimensional Rendering of the Building Showing Sequence of • Construction • Conclusions Senior Thesis Penn State University Spring 2004

33. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield Proposed Solution for a More Economical Mechanical System: Senior Thesis Penn State University Spring 2004

34. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield Proposed Solution for a More Economical Mechanical System: Senior Thesis Penn State University Spring 2004

35. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield Proposed Solution for a More Economical Mechanical System: Senior Thesis Penn State University Spring 2004

36. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield Proposed Solution for a More Economical Mechanical System: • The original system consisted of a large mechanical room on the ground floor of the northeast section of area E which housed 2 boilers and 2 chillers. • The primary pump was responsible for pumping the chilled water from this location to the cooling tower, which is located on the roof in the northeast quadrant of area C. A B F C E D Senior Thesis Penn State University Spring 2004

37. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield Proposed Solution for a More Economical Mechanical System: • As seen on the previous spreadsheet, the largest primary condenser pump was sized based on 60 feet of head loss due to height differentials (static pressure drop), frictional losses (coils, heat exchangers, etc.), and any other pressure drops that may occur. • Placing the boilers and chillers in the rooftop mechanical penthouse will eliminate the need for such a high-powered primary pump since the total head loss will not include the height differential from the ground floor to the roof (approximately 45 feet). • Also, incorporating the rooftop penthouse will greatly decrease the time it takes to route and install all of the piping from the chiller to the cooling tower since it will be a more direct route. Senior Thesis Penn State University Spring 2004

38. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield Proposed Solution for a More Economical Mechanical System: • The following equation can be used to determine the NEW horsepower needed to pump the water from the penthouse to the cooling tower at the same elevation: • An efficiency value of 0.8 was conservatively assumed in order to determine the required horsepower for the new primary pump. Senior Thesis Penn State University Spring 2004

39. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield Proposed Solution for a More Economical Mechanical System: • Based on this information, the following pump was specified as the modified primary pump from Bell & Gossett’s website for online pump selection: Senior Thesis Penn State University Spring 2004

40. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield Proposed Solution for a More Economical Mechanical System: • This particular pump has a 20 HP motor. Based on this information, and the average cost of electricity in PA provided by the Department of Energy’s website ($0.0801/kWh), the total annual savings from choosing this mechanical alternative can be computed as follows: HP x 0.745 x total operating hours = kWh • Assuming the equipment runs all year long at an average of 10 hours per day, 20HP x 0.745 x 365 days x 10 hours = 54,385 kWh • 54,385 kWh x $0.0801/kWh = $4,356 SAVINGS = $10,890 - $4,356 = $6,534 just for the pump alone. Senior Thesis Penn State University Spring 2004

41. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield Addressing Vibration Isolation Due to Rooftop Chillers: • The first means of noise prevention is to simply utilize a thicker slab underneath the penthouse. • To further alleviate this problem, a traditional approach for vibration isolation was taken. Four individual spring-mounted isolators per unit were specified. http://www.vibrationiso.com Senior Thesis Penn State University Spring 2004

42. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield • Presentation Outline • Introduction and Background Information • Discussion of the Problem Statement • Structural Solution - Incorporation of Diagonal Chevron • Bracing • Mechanical Solution - Rooftop Mechanical Penthouse Enclosing Direct • Expansion System • Four-Dimensional Rendering of the Building Showing Sequence of • Construction • Conclusions Senior Thesis Penn State University Spring 2004

43. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield • Reasons for Creating a 4-Dimensional Model of the Building: • More accurate visual representation of the interaction of the new diagonal bracing with the existing conditions of the building. • Better able to see how the members fit in with the facade features, such as windows, doors, etc… • More efficiently able to display the sequence of construction during all phases and correspondingly point out the time savings acquired from changing to a braced frame system. • The newly designed mechanical penthouse is more accurately portrayed in context with the rest of the building. • In general, the animation is a good way to visually tie everything together from all aspects of design. Senior Thesis Penn State University Spring 2004

45. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield • Presentation Outline • Introduction and Background Information • Discussion of the Problem Statement • Structural Solution - Incorporation of Diagonal Chevron • Bracing • Mechanical Solution - Rooftop Mechanical Penthouse Enclosing Direct • Expansion System • Four-Dimensional Rendering of the Building Showing Sequence of • Construction • Conclusions Senior Thesis Penn State University Spring 2004

46. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield • Structural Conclusions: • Choosing a braced frame lateral system has the potential to save a large amount of time AND money: • Monetary savings of $239,250 – with the assumption that a shear connection detail costs approximately 1/3 that of a moment connection. Additional savings from decreased steel tonnage. • It is estimated that the structural steel detailing can be done in approximately half the time required for a moment frame system (107 days vs. 213 days). • Additional consideration for uplift, the implications of installing the bracing between two CMU walls, story displacement, and member uniformity must occur. Senior Thesis Penn State University Spring 2004

47. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield • Mechanical Conclusions: • Choosing to relocate the chillers and boilers from the first floor to the newly designed mechanical penthouse will: • Provide an annual monetary savings of approximately $6,534, which is a result of a reduction in the electricity consumption of the primary pump. • Result in a simpler process of running the piping from the chiller to the cooling tower since the two are now on the same level, saving time during construction. • Open up valuable space on the ground floor since there is no need for such a large mechanical room with this system, which can be used as the School District of the City of York sees fit. Senior Thesis Penn State University Spring 2004

48. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield Senior Thesis Penn State University Spring 2004

49. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield Questions Senior Thesis Penn State University Spring 2004

50. The William Penn Senior High School York, Pennsylvania Presented by Dustin Wakefield Senior Thesis Penn State University Spring 2004