Structural Depth
The staggered truss framing system was developed at MIT in the 1960s, and has since been found to work efficiently in mid-rise, high-rise, and other tall structures. This system is often utilized to create large column-free areas while minimizing floor-to-floor heights. The trusses are spaced a certain distance from each other on the same floor, but the trusses on the floors above and below the level in question are located halfway in between the two, as demonstrated in Figure 22. Their configuration and spacing depend on the floor system being used; thus, the use of precast concrete hollow-core planks will be explored, as it is already a part of the existing structure and will work well in the new system. The loads on the system will have to be reevaluated for the trusses. Additionally, truss members will have to be considered, as the columns and chords will be wide flange beams and the web members will be HSS shapes. Sizes will be determined with a design guide. It is also important to consider how the web members of the trusses will be configured, in additional to how everything will be connected together. Additionally, moment frames will be used to deal with lateral loads.
Construction Breadth
The alternative design for the structural system will change the cost and scheduling for the construction of the building. Trusses are prefabricated and transported to the site so that they can be stored and erected in an efficient manner. Additionally, the floor enclosure can begin after two floors are completed, allowing other trades to begin work immediately. Cranes are also required to hoist up and place the trusses. All of these will require a cost analysis of new materials and labor, as well an investigation into the required change in scheduling in order to determine if the new system is feasible. The placement of the cranes will be studied as well.
Mechanical Breadth
The proposed thesis will investigate the impact of the orientation of Worcester Apartments will have on the mechanical load of the building. Trane-Trace, a load simulation software, will be used to study the difference in loads that are associated with the orientations of the building. A simple block zone model will be developed with assumed generalizations about internal heat gain for each zone. A baseline model with the current orientation will be compared to models with the building rotated every 30 degrees. R-values of various materials and components, such as walls, windows roofs, doors, and floor slabs. The models will be compared with each other, so the comparative results will be valued over the accuracy of the loading.
MAE Coursework
The proposed structural redesign will utilize skills learned during graduate level coursework, specifically AE 530: Computer Modeling of Building Structures. ETABS will be used to build and analyze a three-dimensional model of the structure. Additionally, SAP 2000 will be used to create two-dimensional models of parts of the structure that require further analysis. These results will be checked with the outputs from ETABS.