The purpose of earthquake engineering is not to build strong and earthquake-resistant buildings that do not experience the slightest damage in rare and severe earthquakes. The cost of such structures for the vast majority of users will have no economic justification.
Instead, engineers focus on buildings that resist earthquakes' effects and do not collapse, even in severe external excitations. It is the most important goal of international standards in the seismic design of buildings.
Below I have mentioned some crucial points in reducing the seismic demand in reinforced concrete structures. If there is anything else that is not on the list, feel free to append:
1- Selecting suitable construction conditions with the desired soil type of seismic design
2. Avoid using unnecessary masses in the building
3- Using simple structural elements with minimal torsional effects
4. Avoid sudden changes in strength and stiffness in building height
5. Prevent the formation of soft-story
6. Provide sufficient lateral restraint to control drift through shear walls
7- Preventing disturbance in the lateral behavior of the structure by non-structural components
Applied an equivalent horizontal force acting on each floor according to seismic zone.. also mode a numerical excitation in many cases shows a dynamic load factor (1.5 to 2) or higher!
Dear Abdullah Sikar Al-Issawi
Thanks for the response. However, how is "Applying an equivalent horizontal force acting on each floor according to seismic zone" going to help us reduce the seismic demand in reinforced concrete structures?
Dear Ramesh Gomasa
Thank you for your participation. Could you mention another point besides shear walls? Because it already is on the list (number 6).
Rigid reinforced concrete constructions and very cheap are the prefabricated heavy type houses. If you apply compressive stresses to the cross sections of the wall sides and joints on the ground, with ground anchors, then no failure problems economically and nicely.
On my opinion, Gomasa has given a very good answer, i have recommended the answer.
Dear Mehran see attached a good doc on shear walls design
Dear Mr. Mehran Shahpari,
I disagree with all the opinions given above by different researchers. All of these opinions are based on the conventional approaches in earthquake engineering. However, in my works I am applying innovative approach of low-cost seismic isolation, which solves many problems in design and analysis of buildings.
Usually a structural engineer is facing a dilemma in providing seismic resistance to building. The dilemma is how to minimize interstory drifts but in the same time to avoid increase of floor accelerations. Interstory drifts can be minimized by application of stiff structures like shear walls or braces. But this will lead to high floor accelerations and, consequently, to damage in structural elements or other sensitive internal equipment. From the other side, if the engineer wishes to reduce the floor accelerations by making the system more flexible then this will lead to large interstory drifts and to damage of the nonstructural elements.
Application of base isolation solves the mentioned dilemma, as it simultaneously reduces interstory drifts and floor accelerations with the displacements concentrated only at the level of seismic isolation system.
Hope that the above will be of help to you.
Best regards,
Prof. Dr. Mikayel Melkumyan (Armenia)
P.S. Please also be informed that due to my works I brought Armenia to the second place in the world after Japan by the number of seismic (base and roof) isolated buildings per the number of residents.
I have read your work Dr. Mikayel Grigor Melkumyan, and I am more than happy because of your response.
As an Earthquake engineer, I am pretty aware of how much base isolation can do.
The response was quite informative.
Just a quick question, in the response, you mentioned that “the higher stiffness a structure has, the more acceleration it will experience.” Is the reason for that a lower period? Which leads to a higher acceleration part in the shear base formula? Or it has another reason?
Dear Mr. Mehran Shahpari,
Yes, when the engineer increases the stiffness of the structure, then its oscillation period will decrease correspondingly. This will definitely lead to bigger seismic forces (floors' accelerations) along the height of the structure.
Best regards,
Prof. Dr. Mikayel Melkumyan (Armenia)
check this reference
Article Local Strengthening of Reinforced Concrete Structures as a S...
Also, you might find the answer here
https://www.scielo.br/j/lajss/a/hTXRPS7TQqxwDwYrxHNbZBv/?format=pdf&lang=en
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