The earthquake that struck Nepal and surrounding regions on April 25th and May 12th, 2015 shook more than the earth’s surface. It shook the confidence of residents in hundreds of buildings all over the quake-affected region, across six nations. Buildings in this region, both modern and historic, collapsed or developed irreversible damage during the quakes.
Thanks to the quakes, buyers in India have become cautious and are evaluating a property for its earthquake resistance. The Bureau of Indian Standards has established several norms for earthquake resistant design of structures, in India.
As a prospective buyer, you can ask your builder to share information on whether these norms have been followed while building the structure. You can also engage the services of a structural engineer or professional agency and get an evaluation done.
In addition to this, there are several small details that you can notice, which have a bearing on the earthquake-resistant capacity of a structure.
- Shape of the building(s): The plan of a building should be ideally composite in shape like a square, rectangle, circle, or oval. Buildings in the shape of H, V, L, Y or U are less resistant to quakes.
- Fancy elements: Multiple structural elements that are not tightly integrated with the overall frame of the building are more prone to collapsing during a quake.
- Number of storeys: The load-bearing-wall method that was in vogue during the 70s is risky. While all high-rises use the column principle which is less risky, it’s good to consider low-rises (less than 3 storeys) only if they have been built using columns or framed structure.
- Size of openings in the wall: High-rises that have large openings in the walls for doors and entrances are more at risk.
- Staircases: Cantilever staircases and externally overhanging staircases are more at risk. All stairs must be horizontally integrated with the overall frame of the building.
- Information on the use of earthquake-resistant elements like horizontal seismic bands, vertical reinforcing bars, core shear walls, pile lengths in the rock, mass dampeners, base isolation techniques, etc.
With time, Indian cities will only get taller, so it becomes all the more imperative to follow earthquake-resistant design in construction. While evaluating a property for purchase, buyers must do their due diligence; else, the consequences can be grim and tragic.