Action Plan On Its Way To Make Buildings In Delhi Earthquake-Proof
National capital Delhi is highly earthquake-prone, which is technically called the Seismic Zone -IV. In a situation when disaster is just waiting to happen, concerns over the safety of buildings in the city have been mounting so much so that the Delhi High Court (HC) slammed the authorities for their inaction over setting plans to make the structures earthquake-proof. The HC has given an ultimatum of sorts to the municipal bodies in Delhi to either prepare a comprehensive action plan in four weeks or to be present before the court on the next date of hearing.
A directive, which was not adhered to, was issued in 2015 to make Delhi buildings compliant with requirements of the National Building Code 2005 for seismic zone-IV. Referring to the disaster which struck Nepal in April 2015, an advocate named Arpit Bhargava filed a PIL (Public Interest Litigation) highlighting the threat structures in Delhi face.
MakaaniQ looks at the risks which buildings in Delhi at subjected to:
Some facts that will prove an eye-opener
*Lying close to areas of highest seismic Zone V, both Delhi and some areas of the National Capital Region (NCR) fall on the Seismic Zone IV. The Zone V areas include western and central Himalayas, north eastern India and the Rann of Kutch.
*Many active seismic fault lines run right below the city or close to it. They include the Sohna fault line, Delhi-Haridwar ridge zone, Mahendragarh fault line, Moradabad fault line and Rajasthan boundary fault line.
*As per experts, even a high-intensity earthquake measuring seven on the Richter scale striking the neighbouring hilly terrains of Shimla to Dehradun/Pithoragarh belt can bring down the high-rises in the city.
*According to the National Institute of Disaster Management, nearly 75% of the buildings in the city can be damaged during a strong earthquake.
*The soft soil quality in most areas, especially the Yamuna floodplains make houses in those localities highly susceptible to destruction. These are east Delhi localities such as Mayur Vihar. Some more sensitive include Hauz Khas, Burari, Najafgarh and IGI Airport; Jahangirpuri, Wazirabad, North Campus, Rithala, Rohini and Bawana in the north; as well as central and west Delhi areas of Karol Bagh, Janakpuri, Paschim Vihar, Gita Colony, Sarita Vihar, etc. Places regarded reasonable safe include AIIMS, Vasant Kunj, Naraina, JNU and Ashok Vihar.
What needs to be done?
*The National Building Code of India incorporates in Indian policies the best practices on earthquake-resistant constructions followed worldwide. It prescribes seismic-resistant features in buildings which include provision for small reinforced concrete bands in the walls at the plinth, lintel (above the windows and doors) and roof levels, and various other measures to ‘tie’ the components of the building together.
*Those structures, particularly old buildings, which have undergone modifications, say additional floors constructed, are in dire need of retrofitting. Some buildings have been retrofitted in the past. However, there are many vital buildings like hospitals, control rooms, schools and office buildings that need to be prioritised.
*The prime issue concerns the older buildings in the city constructed 10 years ago. Retrofitting them would cost 20 per cent of the total cost of the structure, and owners in many societies are reluctant on such an investment. Moreover, identification of such buildings is quite a challenge for the government. In 2015, the Delhi government decided to publish a list of 200 structural engineers registered with various civic agencies, for studying the building designs.
*Besides, protection of unauthorised settlements in the city has become another big concern for the government and the municipal corporations.
*Structural audits are a prerequisite if buildings are retrofitted. In Japan, structural safety audits are conducted in every five years. There is a serious need for proper execution of such audits in Delhi.
*Homebuyers, when purchasing apartments from developers, should obtain structure certificate which should state that the building has earthquake resistant elements. The system of issuing a structural safety certificate has already been introduced in many places across the country.
With inputs from Housing News