Considering the current national and global events, safety concerns have driven architects to revisit earthquake-resistant designs in different parts of the world, especially in commercial buildings with larger footfalls and moving crowds, such as public retail spaces, offices, etc. People are looking for safe workplaces that ensure structural stability and user safety during an earthquake. The damage caused is not just by the motion of the ground causing vertical and horizontal movement, but also the after-effects such as landslides, floods, fires and disruption to communication. Hence understanding the seismic history and threats of the locality and the ground you are building on is crucial for structural planning.
The Indian National Building Code has a general set of guidelines that necessitate accounting for seismic data from studies of regional earthquakes as a part of the design brief in the first stages of planning a project for all typologies. The codes such as IS1893, IS 4326, IS 13920, IS 13827, and IS 13828 are some of the essential seismic codes, ranging from general to intensity-specific, lay down regulations to ensure that structures can respond to shocks of moderate intensities without structural damage and to shocks of heavy intensities without total collapse.
Earthquakes not only pose a threat to the users of a structure but also to the surrounding areas in case of a collapse. However, deaths in the case of significant earthquakes happen not due to ground shaking but primarily due to debris and failing structures. In commercial high rises specifically, earthquake considerations need to be made when designing the facade and cladding. Unlike residential buildings, a common trend seen in commercial highrises is the use of glass facades. Without sufficient space around the perimeter of the panes, glass facades cannot tolerate the deformations imposed on the frame by lateral seismic forces, and the glass shatters.
Considering the location of the project and the local history, the necessary design interventions in accordance with NBC regulations must be made right from the planning stage of the project to ensure differential movement of the structure between storeys without transferring seismic forces to the panels. Other non structural elements that can cause loss of life during earthquakes, such as HVAC, interior elements, electrical layouts and clear evacuation exits, are some important design interventions to create safe structures.
Architects and engineers have an undeniable responsibility to create safer and stronger designs that can withstand earthquakes and other natural disasters while providing refuge during such perils, and the safest way to ensure structural stability and strength is by devotedly following building bylaws and codes to build resilient structures.