**To view a PDF version of the REVISED proposal, click HERE (1/11/2012)
*To view a PDF version of the ORIGINAL proposal, click HERE (12/8/2011)
Structural Depth Study:
Problem 1: Structure has an insufficient lateral force resisting system for an increased seismic hazard zone.
Solution: Redesign the lateral system as eccentrically braced frames to comply with code requirements.
Technical Report lll proved that the lateral system of the current structure is adequate in supporting the controlling seismic load case. As an academic exercise, Hunter's Point South will be relocated to a location in a higher sismic region. After moving the current structure to Redding, California, the lateral system must be redesigned to work with increased seismic loading and more stringent seismic design codes. It is determined that usign eccentrically braced frames (EBF) as the new lateral system will be the most effective redesign if the current steel framing system is still to be used. The feasibility of such a system will be explored by analyzing the performance of the EBF and the added detail that is required with it.
Problem 2: Find an effective redesign procedure for the new severe seismic hazard zone.
Solution: Redesign the lateral system using the Equivelant Lateral Force Analysis and Modal Response Spectrum Analysis prescribed in ASCE7-10 Section 12.8 and 12.9.
Seismic analysis of building structures is simplest using the Equivelant Lateral Force Analysis (ELFA). However, there are limitations to this procedure. One of those limitations is requiring the structure to not have torsional irregularity when designed in high seismic regions (ASCE7-10 Seismic Design Category D or higher ). Technical Report lll showed that the current structure does have torsional irregularity. To use the ELFA, the new EBF system will need to be overdesigned to prevent this, which is inefficient. The Modal Response Spectrum Analysis (MRSA) is a more time consuming and in-depth seismic design procedure that will cost more to implement into the design, but it reduces the design loads by up to 85%. Additionally, there are no limitations set for this procedure, and the new sytem can be designed with ignoring structural irregularities. This part of the structural depth will explore whether the more detailed design procedure will create a sufficently more efficient redesign of Hunter's Poitn South.
Gradutae Course Integration:
The redesign of the lateral system of Hunter's Point South will incorporate knowledge gained from several courses in the Master of Architectural Engineering (MAE) program. The redesigned structure will be modeled usign computer modeling programs introduced in AE597 (Computer Modeling). Additionally, the design of the eccentrically braced frames will reference material learned in AE538 (Earthquake Design). Finally, a basic understanding of steel connections taught in AE534 (Steel Connections) will be used to design seismically detailed connections for teh redesigned structure.
Breadth Study 1: Architectural Impact Analysis
Breadth Study 1 will focus on the impact the new lateral system will have on the current architectural layout and visual design of Hunter's Point South. After replacing frames with EBF’s, adding EBF’s to new locations, and relocating current bracing locations to help prevent building torsion, the new system may hinder such thing as door or window openings, or create space limitations in rooms. Also, the new bracing may not be completely hidden away from sight, and a visual assessment must be done both on the exterior and interior to create a visually pleasing structure. This breadth study will focus on redesigning parts of the exterior façade and several interior spaces to work with the new lateral system layout. Changes will be presented through revised floor plans, elevations, and section cuts.
Breadth Study 2: Construction Impact Analysis
Breadth Study 2 will focus on the impact the new lateral system will have on the current cost estimate and construction schedule of Hunter's Point South. Changing location will play a role, but more important to this thesis is the effect the new design will have on the critical path and how it effects the construction time and cost. The new system will be analyzed in a construction management stand point to determine if the redesign is efficient enough in cost and time to be a feasible design economically. Also, a comparison will be done between the two different redesigns to determine whether increased design time for MRSA creates a more efficiently constructed building.