MIXED USE, MULTI FAMILY RESIDENTIAL BUILDING

Structural Depth:

The bulk of the structural design for this Multi-Family Residential Apartment is wood construction. This decision was not the ideal choice for a residential complex of 4 floors, but this was a construction type that the owner and developer was comfortable designing with and had designed previous apartment structures with. Their idea drove the use of wood construction from the end of schematic design and was the main detailed structural system all up into the bid drawing sets were developed. For a 6 story structure, wood design was not at the top of the list for design in this area of the U.S. Therefore, there are many different ways to design a structure for this building while keeping the same architectural layout in the existing structure. 
 

My structural design alternative explores a metal stud bearing wall system on top of structural plywood decking with metal channel floor joists. Through a redesign of the structure, the overall floor depth of structure can be reduced while sticking to the architectural layout of the typical apartment units. One major design change will involve the span direction of the floor joists in each typical apartment from interior bearing walls to exterior and corridor bearing walls. The proposed goal with this redesign is to comparatively analyze how the structure will perform with this new design under gravity and lateral loads. The underlying question is how this type of redesign will hold up against the wood construction design of the existing structure whether it is more efficient, structurally weighs less, or will perform better for the life of the structure.

Acoustical Breadth:
The existing structure wood bearing wall system had many helpful factors play into how the apartment units performed acoustically. As provided and discussed earlier, the floor framing created an interior bearing wall system, with all of the floor joists spanning from interior wall to interior wall of each unit. With that type of layout, it meant that the wood stud members that were selected had to be sized accordingly for the loads and, in some areas, they had to be doubled up. For all of the interior walls, 5/8” of gypsum wall board was added as sheathing. All of those factors added together, to give the existing interior walls a thickness of between 8 to 16 inches. That is a substantial amount of separation between each apartment unit.

For my acoustical breadth, I will analysis the existing wall structure’s acoustical performance and then take the redesign metal bearing wall system and look at its performance as well. The big key factor for my redesign is due to the change in floor joist direction which will span from the exterior wall to the corridor wall. This means that the overall wall thickness for the interior walls will be significantly less than what was previously developed. During the performance analysis, research will be completed on what acoustical standard needs to be met, and if the redesign doesn’t fall within those standards, then methods of approach will be taken to bring the redesign up to the necessary level.

Mechanical Breadth:
With the redesign of the structure , thoughts and considerations were made on how this system can provide a mechanical advantage to the structure. One way that can substantially effect the mechanical load, in the form of heating, is a heat radiant slab system. Now usually these systems are developed in a concrete floor slab and not a concrete metal deck system; however, the idea is to be able to integrate this heat grid into the current metal deck design. Much research and communication with informed persons is involved in such a process as this and there are many avenues that can be taken as a source of breadth for this redesign of the structure. The main point of focus will be if this system can be integrated with the metal deck and what type of performance can be achieved in reducing the mechanical heating load on the structure.