Hi. I think elasticity.

Interesting and important query

Following to learn from experts

Agree with Dr Arief wazwaz..

: Elasticity, viscosity damping, horizontal seismic insulation, plasticity, and dynamics for seismic shifts are all important characteristics

Interesting discussion

Following to learn

My opinion.

According to modern regulations, the seismic design of buildings is based on the ability requirements of the correct design of the nodes and plasticity. The (inevitable) inelastic behavior under strong seismic excitation is directed at selected elements and failure mechanisms.

The philosophy of the correct design of the nodes of the regulations is characterized by the appropriate dimensioning of columns-beams so that we have plastic joints in the beams and not in the columns so that we do not have immediate collapse.

The plasticity of structural elements and structures made of reinforced concrete is characterized by their ability to deform beyond the leakage limit, without significantly reducing their strength.

Elasticity what a nice word!

If the constructions were made of rubber, there would be no problem.

However, constructions are not made of rubber but are made of reinforced concrete and have low elasticity.

If the seismic energy (measured by ground acceleration) is too large, it will produce excessively large displacements that will cause a very high curvature in the vertical and horizontal elements.

If the curvature is too high, this means that the rotation of the sections of columns and beams will be well above the elastic area (Compressive concrete deformation over 0.35% and reinforcement fiber stresses over 0.2 %) beyond the leakage limit.

When the rotation exceeds this limit of elasticity, the structure begins to "dissolve the energy storage" through plastic displacement, which means that the parts will have a residual displacement that will not be able to be recovered (while in the elastic region all displacements are recovered).

Basically the design of the strength of a current building is limited to the limits of the elastic design range, and then passes to the default plastic leak areas, which are default areas of small and many leak failures, (usually designed to occur at the ends of the beams) so as not to collapse the structure.

This is the mechanism of plasticity that consumes seismic energy.

(Structure collapses when oblique / failed columns fail)

If the parts that experience the plastic deformations exceed the breaking point limit, and there are too many on the structure, the structure will collapse.

Basically, plasticity is achieved by placing a dense reinforcing connector at the ends of the elements because this helps to create many and small cracks, avoiding the creation of large catastrophic cracks.

Plasticity is directly related to the cooperation of concrete and steel (mechanism of relevance)

The most serious problem of relevance is created by the ultra-tensile strength of the steel, which turns the failure into a shear form, which is extremely brittle. When the shear stresses in the steel concrete interface reach their limit value, the correlation is destroyed in the form of concrete rupture.

Part of the reduction in stresses is achieved by increasing the overlap and reducing the diameter of the reinforcement bars. The increase of their limit value is achieved by increasing the strength of the concrete. The presence of transverse reinforcement acts favorably by restricting the opening of the developing cracks.

Conclusion

Elasticity is lost in large earthquakes.

Plasticity helps in medium earthquakes but in very large earthquakes the crack leaks become large and if they pass in the area of the fracture and are many, the construction will collapse.

Both elasticity and ductility have a strength limit and then the construction collapses.

Today's seismic construction technology cannot control inelastic deformation and when the earthquake is large with a long duration and the frequency of construction coincides with the frequency of the ground, then the structure that has elasticity and ductility will collapse.

Seismic isolation. It is achieved with the rubber metal bearings with lead core, with the sliding bearings and with viscosity dampers. Also called horizontal seismic insulation Basically, this method tries to isolate the ground from the construction, so that the acceleration of the ground does not pass all over the construction. Ground acceleration is the factor that characterizes the magnitude of earthquake damage, so it is basically right to try to reduce it on construction. The problem is that this is possible and we can only do this with bearings in low-rise structures. In tall structures this is not possible. Tall structures are more at risk from lateral wind loads than from earthquakes, and bearings offer nothing in terms of lateral wind loads. As the weight of the multi-storey structure increases, so does the ability of the bearings to achieve seismic isolation of the structure. Viscosity damping. It is achieved with hydraulic systems that have springs and externally look like car shock absorbers, but are larger and have a different function. These systems basically prevent the displacement of the base of the construction by converting the kinetic energy into a thermal medium of their liquids and achieve attenuation with the spring they carry. Seismic damping is also achieved by the bearing organism itself when it is displaced within the elastic displacement region. The inelastic displacement creates leaks which also release seismic energy. All these systems and the correct satisfactory design of the nodes and the plasticity, contribute to the desired seismic response of the construction and the damping of seismic energy. Problems start when the earthquake is large and lasting.

Dynamic response.

Only the walls have a dynamic response to the earthquake.

The wall is dynamic but not elastic.

The wall overturns and breaks the beams.

Everything has a limit of durability and then the construction collapses.

Is there a solution or when the earthquake is big the structures collapse?

There is a solution but there are no ears to hear me.

What is the solution?

Three factors cause structural failure.

The bending, the overturning moment of the walls, and the problematic mechanism of concrete and steel cooperation, that of relevance.

We stop the bending of the vertical elements by applying compressive force to their cross section.

By the same method, we increase the response to the base shear.

The overturning moment of the wall is prevented when we join all its ends with the foundation ground.

And in the link what we need to do, to eliminate the problems of the relevance mechanism

https://www.researchgate.net/post/The_cancellation_of_the_strength_of_steel_specifications_in_concrete

Experiments

With the patent https://www.youtube.com/watch?v=RoM5pEy7n9Q&t=10s

Without the patent https://www.youtube.com/watch?v=l-X4tF9C7SE&t=19s

https://www.youtube.com/watch?v=IO6MxxH0lMU

The conclusions are yours!

Nice Dr. Loannis Lymperis

https://safetymanagement.eku.edu/blog/5-tips-to-building-an-earthquake-resistant-structure/

Wood and steel have more give than stucco, unreinforced concrete, or masonry, and they are favored materials for building in fault zones. Skyscrapers everywhere must be reinforced to withstand strong forces from high winds, but in quake zones, there are additional considerations.

Even if the structure is well built with reinforced concrete it may suffer if the ground is not bedrock (sold rock).

Bedrock is preferred to soil or to soil with water.

However, in some cases you have no alternative. For example, my father was asked to build a bank in downtown Thessaloniki which was previously part of the sea, now water-logged soil. He devised 400 long concrete pillars pushed into the ground and built the bank on top of these. It has withstood intact through many earthquakes since then.

Dear Michael Issigonis

The structures that are based on soil receive increased acceleration and the reason is because the soil stirs the ground. Static engineers are forced to dig deep to find solid ground. If there is a sea in the ground it is difficult to establish the construction. Your father used cast stakes or friction stakes. These structures usually have basements with large walls of reinforced concrete which act favorably (like anchoring to the ground) For this reason large structures with basements have no problem with axial forces. It has been proven that buildings that have many basements with walls are more resistant to earthquakes.

Stiffness and Strength, Regularity, Redundancy, Foundations, and Continuous Load Path.

An exciting question

Steel and wood based traditional structures are good as compared to other

There is another solution to the problems caused by the earthquake, which no one thought of. I think it is the best solution. If you can not take the forces that a very strong earthquake develops on the structure, then you can divert them and drive them out of the structure by sending them into the ground.

Good question

Good question

Good question

Good question

Good question

Good question

Dear Ioannis,

I recommend "Engineering seismology: Part I" by Nick Ambraseys (1988).

From my experiences this is one of the best entry point to engineering seismology I know: https://doi.org/10.1002/eqe.4290170101.

With best regards, ALEX

I agree with Faraed Salman

Dear Radosław Walkowiak

Low and medium sized buildings are very good to have horizontal seismic isolation. The cost is high. In high-rise buildings, horizontal seismic insulation presents problems with air stability and seismic insulation is limited.

If we screw the construction with walls in the ground it becomes part of it and no other seismic system can be better.

None of the above seismic protection mechanisms could withstand the acceleration of the video experiment.

https://www.youtube.com/watch?v=RoM5pEy7n9Q&t=29s

- electrode effect of the global tectonic activity

- the tectonic vortex

Dear Valentin Constantin Furnica

I did not understand your answer?

Be as clear as possible.

My opinion is just this

The earthquake through the foundation imposes a horizontal acceleration in the construction where, from its size, the destruction index depends.

Constructions had to fly or have the appropriate dynamic response to cope. Unfortunately, the constructions do not fly and do not have the appropriate dynamic response to cope with large earthquakes.

There is no construction on the planet that can withstand an earthquake that will coordinate with the construction and will have great acceleration and duration.

Simply and fortunately, these three asymmetric factors rarely coincide.

But what will happen if these three asymmetric factors coincide and destroy projects of great importance such as hospitals, nuclear power plants?

Of course, some techniques of horizontal seismic insulation and viscosity damping help, but they are very expensive and imperfect in tall buildings.

The good design of the nodes and the plasticity save some lives but completely destroy the buildings.

And the buildings in the next earthquake are remembered

Since the construction does not fly and is forced to rest on the ground the only solution is to increase the dynamic response.

But in order for something to be dynamic, it must be rigid and the rigid is overturned.

Something that is overturned is simply screwed.

on Where?

On the ground.

Believe me, there is nothing more powerful than which we can draw strength and transfer it to the structure to increase its response to the earthquake from planet earth!

https://www.youtube.com/watch?v=zhkUlxC6IK4

My answer looks at this stage "geological structure". But the effect has a universal character, and the vortex is a form of energy organization in all possible scales. So, applications are unlimited.

In a long time, one of the possible electrical interactions could be, according to my observations, an electrode-connection between the seismic source, generator of stress electromagnetic field (in ULF), and construction, which may or may not have a metallic component in contact with the ground. Such a connection can generate a seismic fracture, even if the foundation is on a clay layer, because it is very deep due to the relative depth of the future seismic focus. How can it be removed, in Greece, such an electrode effect set between the building and any future seismic focus from the Aegean tectonic vortex?

20.06.2021

Dear Valentin Constantin Furnica

I can not answer? I have no knowledge of electricity. I join construction with ground. https://www.researchgate.net/post/Engineers_know_everything

I agreed with @ Aparna Sathya Murthy

Dear Houssam Khelalfa

All in one and my patent https://www.youtube.com/watch?v=IO6MxxH0lMU&t=2s

https://www.britannica.com/science/earthquake-geology/Properties-of-seismic-waves

According to the current web page context, elasticity, viscosity damping, horizontal seismic insulation, plasticity, and dynamics are the useful factors that increase the response of the structure to seismic shifts. However, the web page does not provide a clear answer to which of these properties does a better job in an earthquake. You may want to ask the author of the question or read some of the answers provided by other researchers.

A NEW STRONG SEISMIC DESIGN THAT MUST BECOME A SEISMIC REGULATIONAccording to § 5.2.1 of EC8 there is a design option for the available flexibility of thebuilding.Reinforced concrete ( RC ) buildings can be designed using two different design methods.α) To be designed having the necessary plasticity which means having the required -necessary capacity to consume seismic energy, but without losing strength to relativelytolerable loads during the rocking of the earthquake.b) To be designed with low ductility, i.e. low energy consumption capacity, but with veryhigh dynamic capacity.c) As a researcher, I have succeeded in designing a new method of seismic design whichincreases the plasticity and increases the dynamics by merging these two design methods sothat the structure has both plasticity and dynamics at the same time. But I am also doingsomething else even more serious for the first time in the world. Until now, the response ofreinforced concrete sections has been the only defense against earthquake forces. Thedesign I am introducing in seismic technology, besides increasing the plasticity and dynamicsof the structure, besides the fact that the structure can be designed having both plasticity

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and dynamics at the same time, simultaneously removes seismic loads from the load-bearingstructure before they are developed in the cross-sections, and diverts them into the ground.That is, it introduces a new extra massless force derived from the response of thefoundation soil to cooperate with the response of the cross-sections to more easily balancethe seismic intensities of the large accelerations. This method eliminates the inelasticdisplacements and deformations and therefore the failures.This new anti-seismic method introduces in the design the artificial compression (at 70 % ofthe stress) of all the wall faces, with simultaneous consolidation with the foundation soil,using for this purpose strong single pre-stressing tendons and expansion mechanisms whichare stimulated from the ground surface by hydraulic jacks and placed in the depths ofboreholes to achieve consolidation in the ground. Filling the boreholes with resinousconcrete grouts achieves better adhesion and protection of the reinforcement.The load-bearing structure of a reinforced concrete building during an earthquake receivesmoments (M), normal forces (N) (compressive and tensile), and shear forces (Q)The new seismic design method, by means of the prestressing and packing mechanisms,deflects the normal forces (N) of compression and tension in the ground, preventing thecreation of moments (M) in the cross-sections around the nodes and at the same time, dueto the compression of 70% of the s.t., increases the response of the wall cross-sections interms of shear (Q) and base shear by 40%. In addition, the fact that the prestressing tendonsare not in contact with the concrete precludes synergy, (because their passage through thecoating concrete is through plastic passage tubes) ensuring that there will be no shear failureof the coating concrete which occurs due to the excess tensile strength of the steel. Thetension at the wall faces is counteracted by the compressive forces. The pre-compaction ofthe soil by the expansion mechanisms and their filling with cementitious fillings ensure notonly a strong footing but also a strong foundation anchorage. The drilling of boreholes forthe placement of our mechanisms also ensures the control of the soil quality (carrots)Compression generally on the sides of the walls in addition to the mentioned improves theoblique tensile trajectories, restores the cross-sections to their original position by incliningthe inelastic developing cracks and leaks. In this way, the load-bearing capacity of thebuilding is significantly increased and the steel reinforcement is reduced due to the fact thatthere is no longer the shear failure of the concrete overlay which renders the cooperation ofthe two materials useless, as well as that steel and concrete assume only the intensities oftheir strong specifications either steel the tension and concrete the compression excludingthe formation of shear failures along the bars at the concrete-steel interface.Experiment acceleration 2.41g of real earthquake.https://www.youtube.com/watch?v=zhkUlxC6IK4

(7) (PDF) ΝΕΟΣ ΙΣΧΥΡΟΣ ΑΝΤΙΣΕΙΣΜΙΚΟΣ ΣΧΕΔΙΑΣΜΟΣ ΠΟΥ ΠΡΕΠΕΙ ΝΑ ΓΙΝΕΙ ΚΑΙ ΑΝΤΙΣΕΙΣΜΙΚΟΣ ΚΑΝΟΝΙΣΜΟΣ. Available from: https://www.researchgate.net/publication/371290291_NEOS_ISCHYROS_ANTISEISMIKOS_SCHEDIASMOS_POU_PREPEI_NA_GINEI_KAI_ANTISEISMIKOS_KANONISMOS [accessed Jun 16 2023].