The Patent Idea
We have placed on a table two columns, one column screwed on the table, and the other simply put on the table. If one shifts on the table, the unbolted column will be overthrown. The bolted column withstands the lateral loading. We do exactly the same in every column of a building to withstand more lateral earthquake loading. That is done, by simply screwing it to the ground. This pretension between the roof of the structure and the soil has been globally disclosed for the first time.
The horizontal earthquake load generates oscillation, and the result is that the upper plates shift more than the lower ones, the columns lose their eccentricity exerting a lifting force on the bases, as well as creating a twisting action in all of the nodes of the structure.
The ideal situation would be if one could construct a building framework where, during an earthquake, all the plates would shift by the same amplitude, at the ground without differing phases.
The research I have carried out resulted in just this. The method of the invention eliminates all these problems of deformation in the building construction applying pretension, through the mechanism, between the roof of the structure and the soil.
The skeleton of a building consists of the columns (vertical parts) and the girders and slabs (horizontal parts). The girders and slabs are joined at the nodes. Under normal conditions, all loading is vertical. When an earthquake occurs, additional horizontal loading is placed on the skeleton. The resultant effect of horizontal plus vertical loading puts strain on the nodes. It alters their angle from 90 degrees, creating at times acute and at other times obtuse angles. The vertical static loads equilibrate with the reaction of the ground.
The horizontal earthquake load exerts a lifting effect on the bases of the columns. In addition, due to the elasticity of the main body of the columns, the earthquake acts by shifting the heights of each plate by different amplitude and a different phase. That is, the upper plates shift more than the lower ones. The modal shifts of the skeleton are many, so many that the differing, shifting directions of the earthquake deform and destroy the skeleton.
The ideal situation would be if we could construct a building skeleton where, during an earthquake all the plates would shift by the same amplitude as the ground without differing phases. In this way the shape will be preserved and we would not have any deformation of the frame, hence no damage. The research I have carried out has resulted in the creation of an anti-seismic design for buildings which achieves exactly this result.
I have succeeded in doing this by constructing large elongated ridged columns shaped “−, +, Γ or T” to which a pulling force is applied from the roof and from the ground, applying bilateral pressure to the entire column. This force acts to prevent bilateral shifting of the columns and curvature at their bases so preventing the deformation which occurs throughout the whole structure during an earthquake.
In an earthquake, the columns lose their eccentricity and their bases are lifted, creating twisting in all of the nodes of the structure. There is a limit to the eccentricity, that is, there is a limit to the surface area of the base which is lifted by the rollover moment. To minimize the twisting of the bases, we place strong foot girders in the columns. In the large longitudinal columns (walls), due to the large moments which occur during an earthquake, it is practically impossible to prevent rotation with the classical way of construction of the foot girders.
The following result occurs with this lifting of the base in combination with the elasticity. When one column of the frame lifts one end of the beam upwards, at the same time the other column at its other end moves violently downwards. This stresses the beam and has the tendency to twist it in different directions at the two ends, deforming its body in an S shape. The same deformation occurs with the columns also, due to the twisting of the nodes and the differential phase shift of vertical plates. In order to prevent the lifting of the base, we clamp the base of the structure to the ground using the patented mechanism.
However, if we want to prevent the lifting of the whole columnar structure which stems from the lifting of its base as well as from the elasticity of its main body, then the best point for enforcing an opposing, balancing force is the roof. This opposing tendency on the roof must come from an external source and not applied from within the structure. This external source is the ground underneath the base. From here the external force is applied.
Underneath the base of the structure, we drill a hole into the ground and clamp it with the patented anchor. With the aid of a cable which passes freely through a pipe in the column, we transfer this force which we obtained from the ground up to the roof. At this point in the roof, we insert a stop with a screw to prevent the raising of the roof of the longitudinal columns which happens during an earthquake and deforms all the plates. In this way, we control the oscillation of whole structure. That is, the deformity which the structural failure causes. With this method, we do not see changes in the form of the structure, because it maintains the same shape it had prior to and during the earthquake.
With the design method, of the clamped structure from the nodes of the highest level with the ground, hope I will deflect the inertia tensions of the construction and direct them straight into the ground, removing those from the areas currently driven, preventing and avoiding deforming shapes, which are so many, as well as the various directions of earthquake displacements, so that the tension in the structure, to appear limited, while at the same time ensuring a stronger bearing capacity of the foundation soil. If we design the correct dimensioning and shape of the walls, and place them in appropriate locations, we prevent the torsional buckling which appears in asymmetrical and metallic high-rise constructions.
Generally, the inventive design method offers absolute anti-seismic protection because it stops the construction deformation in the earthquake.
So we ensure security by protecting our home, protecting our lives and its inanimate content.
Αt the same time, you achieve economy, from repairs.
Analytically.
1) Stops bending on all trunks of beams and pillars
2) Maintains the base foot always horizontal and glued to the ground, preventing it from turning around the joints of its edges.
3) Increases the strength of the concrete limit value to the cuts by applying stresses to the cross sections.
4) Minimizes torque at the nodes as well as the torque of the wall, as it creates a torque of stability against the torque of the wall.
5) Increases the foundation soil's capacity for receiving vertical loads.
6) Removes the shear failure of concrete in relevance, due to steel over-strength.
7) Removes the lever arm mechanism.
8) Ensures that the concrete only accepts stresses of tension (in which it can withstand 12 times more than it is tensile) and steel only tensile strengths.
9) Eliminates the floor mechanism, the critical failure area and the potential difference of the stresses
10) Increases the active cross-section of the wall. 11) Eliminates cracking 12) Improves oblique tension.
13) Prevents building bounces on the ground that increase vertical loads.
14) Sampling the soil quality during drilling work. 15) Eliminates inertial tensions and leads them into the ground, preventing them from being driven over the cross-sections of the structural elements.
16) Zero period, prevents coordination
17) Stops the phase difference of the floors.
18) Achieves reduction and elimination of tensile stresses in vertical concrete elements
19) Stops the torsional buckling
20) Smoothes the dimensions in the bases, and removes part of the reinforcement.