By: Rakesh Lohumi, Sr. Editor-ICN Group
The modern reinforced cement concrete (RCC) buildings are vulnerable to damage during quakes as they lack flexibility and unsuitable climatically.
SHIMLA: Moderate tremors, like the one which shook parts of northwest region last night, are a constant reminder for the Himalayan States and the people that they are sitting on a geological bomb that could explode any time. There has been an increase in frequency of such tremors in recent years but still no long term preventive measures are put in place to mitigate fall out of such calamities.
Instead, their destructive potential is being enhanced manifold by implementing reckless development policies as evident from excessive and unregulated construction activity that is taking place across the fragile mountain range.
The Bureau of Indian Standards has classified the country into four seismic zones, from Zone V, the most active, to Zone II, the least active. All the Himalayan states right from Jammu and Kashmir to northeast fall in Zone V and Zone IV.
The Zone V consists of parts of Jammu and Kashmir, Himachal Pradesh and Uttarakhand, making the three northern states most vulnerable. Further, these high risk zones also coincide with the areas with high concentration of population and that only increases the destructive potential.
The common refrain is that earthquakes do not kill people; deaths and damage are caused by collapse of poorly built manmade structures. Seismic activity is a natural phenomenon over which the man has no control but the scope and scale of devastation can be minimised by ensuring planned development of the region and strictly and uniformly enforcing the seismic code for structural safety.
This can be done only by focusing on the pre-seismic event phase. A comparison of the two major quakes which struck Haiti and Chile in 2010 within a space of six weeks provide an idea of the extent to which interventions can mitigate the impact and bring down the casualties and damage to structures.
A tremor of magnitude 7 on the Richter scale virtually flattened Haiti on January 12, killing over 2.20 lakh people, while a very high intensity earthquake of magnitude 8.8 that rocked Chile on February 27 caused minimal destruction and claimed just about 600 lives.
Poorly engineered and badly constructed structures along with lack of preparedness to cope with such calamities spelt doom for Haiti. Lax building regulations and their indifferent enforcement, poor quality of construction and rampant corruption accentuated the impact of disaster. Even the quality of engineered structure was poor and they crumbled.
In contrast, learning from the past tremors, particularly the 9.5-magnitude quake of 1960, successive Chilean governments evolved and enforced high construction standards as a result of which the buildings got damaged and even tilted but did not collapse. This was the main reason for low death toll.
Given the high level of corruption and lax implementation of building regulations in the country the impact will be more like Haiti. High-rise structures have come up on steep hills in violation of the building laws and in utter disregard to the slope norms.
Most of the hill towns, particularly tourist destinations like Shimla, Manali and Dharamasala, have already been transformed into veritable concrete jungles and the construction activity is now spilling over to the rural areas.The trend is picking up in Uttarakhand and areas near Nainital like Shyamkhet, Bhawali and Ramgarh are witnessing intensive construction activity.
The entry of builders in the housing sector has made things worse and over the past decade and apartments are coming up on the pattern of plains. Politically influential realtors are having a field day and building laws are being changed to suit their commercial interests.
Built on open spaces the old timber-farmed houses, which provided safe and healthy environment, are being phased out. These elegant structures are not only resistant to quakes but also blended well with the natural hill settings and more suited to the hill climate. The modern reinforced cement concrete (RCC) buildings are vulnerable to damage during quakes as they lack flexibility and unsuitable climatically.
( To Be Continued….)