Although the design of this building is unique and different, the structural elements are quite common. It seems to be an incorporation of a steel lattice surrounding a concrete core which runs into the earth to form the foundation of the structure. The sub-floors of the building are most likely poured concrete which help in the stability of the structure. In addition to the main structure, Egon has designed a light steel superstructure which acts as a shelf over the building and is utilized to support the balconies and sun shades.
The structural study in this project will be focused on the inverted towers. This design raises many questions to standard structural principles. why would someone go against normal design strategies to design a structure that is less sound than the tra
ditional means? my guess is that this building is basically an aesthetics statement for some reason or another. Another burning question in our minds is why the foundation of the building breaks the surface of the earth. One would think that the founda
tion of this kind of structure would have to be pretty massive in order to anchor the building for stability. The loads this building will most likely undergo are the live loads of the wind and people and the dead load of the structure itself. We have a
lso assumed that because Germany does not li on a fault line they will not experience any earthquakes, thus enabling such a weak foundation for their buildings. Although our main concerns have to deal with the principles concerning the inverted towers, t
his building also explores the fields of tension details, trusses and horizontal cantilevers.
As a downward acting load is applied to a typical bay floor in the upper part of the tower, the flooring material transfers the load directly beneath to the floor superstructure. We are guessing that the structural flooring is made up of poured concrete slabs. From here the load is transferred to the nearest steel beam. These steel beams between the floors span roughly twenty-two feet in an almost radial direction, from girders around the periphery of the building to the girders around a rectanfular tu be core of columns at the center.
Now, if we take a more detailed look at the transferring of the vertical load we will see that it is split into two paths. Imagine taking a vertical section of the building which runs from the foundation to the top of the structure. Because this buildin g is symmetrical down the middle, we will only discull half of the building. For it will be the same for both sides. This section would constist of the core to the slab to the exterior wall, which slims and connects to the core near the base of the buil ding. Now, if the load is applied on the inner half of the beam's span, the beam carries it horizontally to a girder which is attached to huge steel columns in the core of the building, which in turn run into the shallow foundation beneath the earth. Th e foundation itself has a larger area than the core, but at the same time somewhat less of an area compared to the perimeter of the upper floors. The increase of the foundation, compared to the core, is justified by reducing the stress imparted to the ea rth.
Now, on the other hand, if the load is applied to the outer half of the beam, it is horizontally directed to a steel girder around the building's periphery. This is attached to steel columns whidh run from the top of the tower's edge, at the sixteenth st ory, down to the columns on the eighth floor. When the load reaches the base of the columns located on the eighth floor, the loading is directed into the core's columns through a forty-five degree column or slab which connects the two. Here the columns of the core thicken, as they now must carry twice the load as they did before encountering the forty-five degree support. And this is the system through which the vertical loads are transferred from the top of the building to its foundation.
Lateral Loads
The lateral loads of the Olivetti towers are a bit more complex in their understanding when compared to the vertical load system. These towers resist the lateral loads by transferring them inward, through rigid connections which transfer moments, to a ce
ntral core. This core is encased in concrete shear walls which are fixed at the ground. The building basically acts as a rigid cube, defined by rigid steel connections and not cross bracing, with a cantilevered column inserted into it and suspending it
above the ground.
If a horizontal load is exerted on the facade of the building, such as a wind load, the skin, which consists of mostly glass, carries the load to the nearest girder along the outer periphery. The girder will then begin to bend inward due to the load, pu tting the floor beams into axial comression. This will, in turn, put the inner girders into bending, which will be resisted by the two walls located in the core which run perpendicular to that girder. The core is a closed rectangle in plan, thus enablin g it to resist lateral loads from all directions. The core walls act as rigid pieces with one end buried beneath the earth. The grounding of these walls increase the stability of the structure immensely. As the girder pushes on the upper end of the wal l it will tend to rotate at some lower point. this rotation will be resisted below the point of rotation by the earth, which in turn must also exert a horizontal force on the walls of the foundation.
One last consideration we must look at in the resistance of the lateral loads is whether or not the connection between the towers and the rest of the building is structural or not. Because both of the towers have a connection to the lower two story build
ing between them, we have to wonder if this connection adds stability when encountered by lateral loads. If the connection was structural then the lower building and also the other tower would act as an extension of the tower's foundation, thus securing
it firmly in place. But if this connection was structural, then the question is raised whether or not the towers can stand on their own. If the rest of the building is going to be torn down, or if the lower two story building must undergo major renovati
ons and that connection has to be altered for a while, can the towers still stand? If not that would be a major tragedy, and seem quite silly. For the towers to have this kind of dependency on the rest of the building seems awkward. From these thoughts
we have concluded that the connection between the towers and the lower building is purely functional and not structural.
Zack Emmingham and Brandon Sanchez
ARCH 461/561 Spring 1995
Do you have questions about adding a case? or a building to suggest??????? send a message to me....... chrisl@aaa.uoregon.edu