Earthquake retrofitting is the process of modification of the existing structures to make them more resistant to seismic activity, ground motion, or soil failure due to earthquakes. It is usually done to earthquake damaged buildings and earthquake vulnerable buildings.
Retrofitting is necessary for public safety that the structure will not fall on the occupants or passerby, as well as for the long life of structures. There are different methods for retrofitting. Some common methods are explained here.
Adding Shear Walls
It is usually used for the retrofitting of non-ductile reinforced concrete frame buildings. The added elements can be either cast-in-place or precast concrete elements. They are avoided in the interior of the buildings to avoid interior moldings.
Adding Steel Bracings
It is one of the best solutions applied when large openings are seen in a building structure. It provides higher strength and stiffness to the structure, while at the same time, adds less weight to the structure.
It is the most popular method for strengthening building columns. Jacketing is the process by which a section of an existing structural member is restored to original dimensions, or increased in size by encasement using suitable materials. There are different kinds of jacketing like steel jacketing, reinforced concrete jacket, fiber reinforced polymer composite jacket (FRPC), etc.
Isolation of the superstructure from the foundation is known as base isolation. It is the most powerful technique for passive structural vibration control. There are various kinds of base isolation techniques. It is an expensive method and not suitable for soft soil.
Seismic dampers partly absorb seismic energy and reduce the motion of the structures. They are used in place of structural elements like diagonal braces. They are of different types, such as viscous dampers, friction dampers, and yielding dampers.
In viscous dampers, energy is absorbed by silicon-based fluid passing between piston- cylinder arrangements. In friction dampers, the energy is absorbed by surfaces with friction between them rubbing against each other. In yielding dampers, energy is absorbed by metallic components that yield.
Apart from these, several new methods are also used for earthquake retrofitting these days. Get in touch with our experts to learn more on the various methods available, and settle on the best and suitable method for you.
Posted on Monday, January 15th, 2018.