Technical Assignments

Technical Assignment 1

Executive Summary

 

            This paper is the first of three parts of the preliminary analysis of the design of the office building at 1000 Continental Square in King of Prussia, PA. This analysis will act as the basis for the later research around which my thesis will concentrate. The building is a high-end office space, featuring large, open floor plans with uninterrupted forty-foot bays along each side of the building.  This building is located along the prominent intersection of Pennsylvania Routes 202, 76 and 422; and is in close proximity to a Pennsylvania Turnpike interchange and the King of Prussia Mall. The building has a partially sub-grade ground floor mainly for mechanical systems and storage with five floors of leasable space above that. The structural frame is steel with composite concrete slabs, and lateral loads are resisted by two moment frames along the long axis of the building and two eccentrically braced frames along the short axis. These systems are expounded upon later in this report, as well as calculations and spot checks verifying their adequacy. In typical cases, most members appear to be designed conservatively.

Technical Assignment 2

Executive Summary

 

            This is the second of three preliminary stages of analysis intended to impart a better understanding in each student of their individual building, and acts as an attempt to better focus research for the final thesis in the spring. This second report consists of a more in-depth analysis of the building’s existing floor system as well as a “pro vs. con” investigation of four alternative flooring systems. The floor systems I chose to analyze in addition to the existing composite slab were:

• Precast Hollowcore Planks on Steel Beams

• Precast Double Tees on Steel Beams

• Cast-in-Place One-Way Slab with Wide Shallow Beams

• Two-Way Post-Tensioned Slab with Drop Panels.

            My choices in floor systems were rather limited due to the large size of the spans and heavy live load. Systems such as a standard two way flat plates and steel joists are simply unable to deal with such loading conditions. Some other options might have been available had I changed the column grid and created shorter bays, but this would have interfered with leasable space and made the value of the property drop, two scenarios which were definitely not acceptable for the original design team.  By adhering to the design constraints which were placed on the original building, I arrived at several preliminary conclusions. The existing system is probably best suited to optimizing the current design, but redesigning the building in concrete with two-way PT slabs has potential. The one-way slab’s thickness is appealing, but it is just too heavy and expensive to compete with the two-way. This is one design that might have fared better had I divided the bays into shorter spans. Perhaps, a combination of the two concrete designs could be used to reduce the need for deep drop panels in the PT slab. Both of the precast alternatives ended up being too thick to be practical; they left no room for mechanical systems, and less efficient beams had to be used to salvage the system depth, otherwise it would have been larger than four feet in both cases. The two-way PT slab is the only option that will be fully considered in future reports. The results from this stage of analysis are only intended to be used to rule out unacceptable alternatives. As a result, the design of the PT slab will have to be refined and drop panels, or some alternative method to reduce shear will have to be investigated in later calculations.

Technical Assignment 3

Executive Summary

 

            This is the third of three preliminary stages of analysis intended to impart a better understanding in each student of their individual building, and acts as an attempt to better focus research for the final thesis in the spring. This third paper focuses on the lateral force resisting systems and how lateral loads are distributed to different elements in those systems. My project is based on the design of the office building currently under construction at 1000 Continental Square in King of Prussia, PA. The building is high end office space featuring large open floor plans with uninterrupted forty foot bays along each side of the building. The site has a prominent location at the intersection of routes 202, 76, and 422, and is in close proximity to the PA Turnpike and King of Prussia Mall. A ground floor, partially below grade, serves mainly as space for mechanical systems and storage. Five floors of approximately 36,000 square feet of leasable space are located above that. The building makes use of a steel structural frame with composite metal decking and lightweight concrete slabs. Lateral loads are resisted by two moment frames along the long axis of the building and two eccentrically braced frames along the short axis.