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Old Posted Sep 2, 2014, 5:32 PM
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seismic seismic is offline
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Join Date: Feb 2010
Location: ISLAND OF IOS CYCLADES
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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 a 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 minimise 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.

The reaction of the mechanism to the raising of the roof of the longitudinal column and the opposing reaction of the at the bottom part of the base, divert the lateral load of the earthquake into the strong vertical section.

With this diversion of the lateral load of the earthquake to the vertical columns, the twisting of the nodes is abolished because the lateral loadings of the earthquake are 100% borne along the length of the columns, so it is impossible for them to twist in their main sections.

In the experiments I have carried out in actual scale earthquake acceleration of 1.77g and amplitude over 0.11 in a two story building model to scale 1:7.14, the difference in the model with and without the patented mechanism can clearly be seen.

See the link below for the experiment:
https://www.youtube.com/user/TheLymperis2/videos
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