One of the reasons why earthquakes take a heavy toll is the poor quality of construction. The Government must accord high priority in the implementation of building regulations and ensure compliance through periodic checking
Nepal was struck by a massive earthquake in 1934. Eighty years later, the Himalayan nation was again hit by a big earthquake on April 25 — this time, even worse than its predecessor. The number of dead has already surpassed 5,000 people with 9,000 people injured. According to Nepalese Prime Minister Sushil Koirala, the death toll could reach 10,000.
Over the years, many people have migrated to Nepal’s capital city, making Kathmandu valley one of the fastest growing metropolitan areas in South Asia. Not withstanding the hazardous geological and seismic position, the valley has witnessed a flurry of construction activities.
As a result, the un-reinforced masonry buildings — some eight-storey high, proliferated, with many of the buildings having open storefronts on the first floor. This made the structures weak at the base.
On April 25, a 7.8 magnitude earthquake (according to Richter scale) followed by a 6.6 magnitude aftershock rocked that country. The weak structures succumbed within seconds and human casualties started to mount.
The situation became worse because the capital city is located on a one-time lake-bed. This increases the risk quotient as the soil being loose, amplifies the tremor in case of an earthquake. The effort by the Nepal Government to contain unsafe construction was articulated through a national building code, introduced a decade ago. But the actual implementation at the municipality level moved at a snail’s pace, and the progress has been unfortunately overtaken by the natural disaster.
Closer home, the situation pertaining to the quality of construction and enforcement of building norms is grim as well. A survey by the National Disaster Management Authority found that, in the last 25 years, more than 25,000 human fatalities were caused primarily due to the collapse of buildings during earthquakes. Most cities in India suffer from a vulnerable flaw in the form of weak buildings that can magnify the damage during a medium intensity earthquake.
Delhi falls under the seismic zone IV, and can suffer extensive damage if an earthquake of the same magnitude as in Nepal were to hit the city. This vulnerability stems from the fact that nearly 70 per cent to 80 per cent of the buildings are in violation of the Building and Development Control Regulations laid down in the National Building Code of India, 2005.
The inability of the Government to check this due to the shortage of official manpower, is adding to the woes. As sub-standard construction work continues unabated, the problem is only getting bigger day-by-day, and only about 15 per cent of the completed buildings conform to the approved plan.
Given the high incidence of natural disasters nowadays, it is crucial for the Government to accord top priority in the implementation of the building regulations and ensure the compliance through periodic checking and fixing accountability with the enforcement departments concerned. It is also essential to ensure a non-negotiable set of building bylaws that prevents critical risk factors compromising building safety, such as two large buildings sharing a common wall or multi-storied buildings on stilts.
In order to ensure better seismic performance of the urban structures, newly constructed houses must abide by the National Building Code of India, 2005, the Master Plan of the respective cities and also the Vulnerability Atlas-2006. Moreover, the practice of handing over the construction work to ill-trained and non-professional contractors and masons must be discouraged.
Apart from ensuring strict implementation of the building laws, the Government must increase awareness among the people on the high costs associated with construction standards that do not comply with the norms. In addition, people must be encouraged to get their structures evaluated for stability and integrity. In order to urge people to come forward, the authorities can also explore providing certification for approved structures, besides providing financial assistance for retrofitting old buildings to make them safer.
Many countries across the world are combining the twin benefits of effective building regulations with earthquake engineering to arrive at a robust counter-strategy for earthquakes and their devastating impact. Earthquake engineering is the scientific field concerned with protecting society, the natural and the man-made environment from earthquakes by limiting the seismic risk to socio-economically acceptable levels. One of the often quoted and successful examples of earthquake engineering is the Taipei Tower in Taiwan.
Known as Taipei 101, the tower is designed to withstand typhoon winds and earthquake tremors common in its area of the Asia-Pacific. Planners aimed for a structure that could withstand gale winds 134 mph and the strongest earthquakes likely to occur in a 2,500 year cycle. With expertise available such as this, it is unfortunate that people continue to suffer from the vagaries of natural disasters.