Lateral Stability of Structures provides resistivity from the lateral forces applied by high-velocity winds, earthquakes on high-rise buildings.
It seems easy to construct a building without engineering knowledge by simply casting columns joining beams and construct the whole building.
This scenario completely changes in the case of high-rise buildings.
It is necessary to design the building for the worst-case scenario.
As it has a once-in-a-lifetime chance that the building will experience that velocity and magnitude of winds/earthquake.
There are several events in the past that mandate the sustainability of structures in the case of high-rise buildings to ensure the safety of the people in the building.
Also, Read:- Types of Heavy Equipment Used in Construction
World Trade Center is commonly known as Twin Tower in New York faces a terrorist attack and 3000 people were killed.
Therefore, to ensure the safety of humankind while designing these buildings. There are several techniques to keep in mind while designing buildings.
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Lateral Force Resisting System
Lateral Force Resisting System is also called a rigid frame, it provides resistivity against the induced vibrations and forces on the high-rise buildings.
It is the technique that helps in making building more impact resistance.
If we take an example of a man standing and his legs did not have space between.
If someone pushes this man from the side or from the front, the man could easily topple over.
If a man spread his legs in a shoulder-width now it depends on from which side you are pushing if you push him from the sides then the man could easily brace himself.
This is the same phenomenon in high-rise buildings.
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Types of Lateral Forces
The Lateral Force Resisting System basically used to resist lateral forces. These lateral forces are of two types:- Seismic Force, Wind Force.
Seismic Forces are the forces that are applied to the structure due to seismic activities like earthquakes.
They always impact the structural elements which are close to the foundations.
Wind Forces are the forces that cause horizontal loading on the structure.
The building is designed by the quasi-static analysis and tested by the Computational Wind Tunnel (CWT) tested by several civil engineering software products like Autodesk Flow Design.
Bracing of structure is the necessity of the building for lateral stability of the structure as it provides more stiffness to the building.
The wall bracing in structures is provided by analyzing the structures whether the structure is sway or non-sway.
This is a video for sway and non-sway structures. You can brush up on your concepts for sway and non-sway structures.
In the case of RCC structures, joints between the elements must be rigid to prevent deflections when the lateral load comes on the vertical elements of the building.
To prevent deflections we have to provide additional reinforcement and make the column bulkier.
As it provides a wide opportunity for architects and designers to design buildings as per their choices and needs.
Common Structural Elements used in Designing
Common Structural elements used in designing are based on the types of structure whether the structure is concrete structure, masonry structure, Steel framing structure.
Concrete and Masonry Structures
When we design concrete and masonry structures to resist lateral forces concept of Shear walls and Core walls are used.
Shear Walls are the structural elements generally used in high-rise buildings as they resist lateral forces like wind forces, seismic forces.
They help to create a more moment-resisting frame of the building.
Shear walls are generally to prevent shear failures in building due to its self-load or live load of the structure, and it creates torsional forces by lateral pressure.
It also helps in the lateral stability of the structure by increasing the width of structural elements.
The deflection between the vertical load-bearing elements should not be more than the ceiling height divided by 500.
Core walls are the types or combinations of shear walls. They play major roles in the lateral stability of the structures.
Core walls are always constructed from the foundation of the building. They are always present at the geometric center of the building.
Elevator Shafts are generally used in the construction of the core walls as they are dead areas for the architects.
The core walls themselves act as a column they can be used as step wells, staircase.
Core Walls are considered as more efficient lateral force resisting elements than shear walls and braced frames as it also prevents the overturning of the structure.
The thickness of the core wall depends on the height of the building.
Also, Read:- Compressive Strength of Concrete – Cube Test, Result
This is all basics about lateral stability of structures, we’ve discussed the basics concepts of the lateral stability of high-rise buildings. This will you help to design the structure of the high-rise building.
The implementations of these concepts will make a more stable and safe structure.
Thanks for reading this article. We’ll be back with some more concepts of Structural Engineering.