The ground shifts with acceleration, the magnitude of which depends on the amplitude of the oscillation and the frequency in units of time (1 sec). The columns receiving this acceleration try to displace the plates, which react in the opposite direction. This reaction is called inertia and its magnitude depends on the mass and the acceleration.
These two opposing forces create the base shear, which cuts the column near the base, and is therefore called the base shear. Its magnitude is the same as that of inertia.
If the columns are not cut, they elastically transmit this displacement to all the plates in height, which begin to sway sometimes to the left and sometimes to the right. If this oscillation has the same frequency as that of the ground, an eigenfrequency or eigenperiod is created, which gradually increases the displacement of the floors and the stress on the columns until they deform and break.
The deformation of the columns and the increase in displacement of the plates at the top level occurs due to elasticity and inertia. The columns and walls at height work together to form a whole from the base to the top of the structure. So they are seen as huge levers that transfer multiplied torque forces to the base.
These moments have the magnitude that results from the product of the mass of the plates multiplied by the height at which they are located. Typically, these moments break the columns before they reach the base due to bending. The walls, however, being more dynamic and rigid, transfer them to the base. The connecting beams try to pick up these moments, but they fail at high accelerations with many floors. The columns fail before the moments even reach the base.
The twisting of the walls, which are connected to the slabs by the beams, breaks the beams, which initially resist. The plates begin to fall on top of each other. This is the process by which civil engineers see the structure collapse.
I have a design proposal that prevents the walls from twisting and bending, and eliminates the transfer of moments to the beams to prevent them from breaking and collapsing the structure.
What I do: I install large, stiff walls instead of columns and apply artificial compression to their cross-section, increasing their stiffness and strength with respect to the base shear. Thus, they do not cut, bend, fail in tension and transfer moments to the beams. The walls are also pressed into the ground by the roof to stop their bending, which along with the bending of their frame, breaks the beams and plates.
The footing deflects the moment into the ground, preventing it from being directed into the beams and preventing settling. The resonance no longer exists, as the force of the ground stops the turning and bending of the walls, stopping the increase in resonance oscillation over time.
Article The Ultimate Anti-Seismic Design Method
In construction, earthquake considerations involve designing structures to withstand seismic forces. This includes using flexible materials, reinforcing buildings, adhering to seismic codes, and incorporating techniques like base isolators and damping systems to reduce damage and enhance safety during earthquakes.
Dear Dr. Chuck A Arize
That's all well and good. But why don't we also use the external force of the ground (which has no mass so does not increase inertia ) to increase the earthquake carrying capacity of the structure? Why don't we use the pre-tensioning at the ends of the walls to increase the stiffness and dynamic of the sections?
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