Rabinder Shekher &
Life is precious and it is thus foremost responsibility of everyone to protect his/her life. We must understand that life has no retake and as such there must be left with no option to try for the retake. Sir Isaac Newton once said that every day we build many walls for ourselves but are very conservative in having enough bridges. But in my opinion we are very rude in building good walls even. A number of lives are lost every year in manmade structured walls (Houses/Tall structures).We have been witnessing earthquakes and a large number of precious lives are lost now and then. It is not the earthquakes that are killing the masses about the structures constructed and designed by the engineers which don’t withstand the jerks and jolts of earthquakes and collapse and subsequently kill the people.
An earthquake is a sudden tremor or movement of earth’s crust, which originates naturally or below the surface. The word natural is very important here, since it excludes shock waves caused by nuclear tests, manmade explosions and landslides caused by the building work. An earthquake can be linked to the effect observed when a stone is thrown into water pond. After the stone hits the water surface, a series of concentric waves will move outwards from the centre. The same phenomenon happens in an earthquake. There is a sudden movement within the crust or mantle, and concentric shock waves move out from the point. Geologists and geographers call the origin of the earthquake the focus. Since this is often deep below the surface, difficult to map, the location of the earthquake is often referred to as the point on the earth directly above the focus called Epicentre.
The earthquake produces three types of waves which have their own distinct characteristics and can only move through certain layers within the Earth. The strength, or magnitude, of the shockwaves determines the extent of the damage caused. Two main scales exist for defining the strength, the Meracalli Scale and the Richter scale. The latest earthquake of April, 2015 Nepal earthquake killed more than 88oo people and injured more than 23000. It occurred on 25th of April, with a magnitude of 7.8 on Richter scale. Its epicenter was east of district of Lamjung, and is hypocenter was at a depth of approximately 15 Km. It was the worst natural disaster to strike Nepal since the 1934 Nepal- Bihar earthquake. The J&K earthquake of 2005 and many more have made people to tremble with the word Earthquake.
The interesting thing about safety from earthquake is that once taught/demonstrated methods about hiding under a table or standing in a doorway or simply ‘ ducks and covers’ when buildings collapse are crushed to death and people who get under objects like desks or cars are also crushed. This is an Eye Opener for the engineers in particular and the public in general today. Mr. Doug Copp., a rescue Chief and Disaster Manager of American Rescue Team International, the world’s most experienced rescue team has demonstrated the methods of saving the human life by way of different easy and simple tips. He has written an article on earth quakes and titled it “The Triangle of Life”. According to him, he has crawled inside 875 collapsed buildings, worked with rescue teams from 60 countries and have worked at every major disaster in world since 1985, except for simultaneous disasters. In Mexico City during 1985 earthquake, every child in a school was under its desk and every child was crushed to the thickness of their bones. They were probably given demonstrations for the safety against the earthquakes by the authorities but they could have survived by lying down next to their desks in the aisles, A Triangle of Life. Simply, when a structure collapse, the weight of slab, beam etc falling upon the objects or furniture inside crushes these objects, leaving a space or void or A triangle next to them. This space or Triangle becomes life saving space. These spaces are everywhere. The less the object compacts, the larger the void, the greater the probability that the person who is this void for safety will not be injured. The next time when you watch collapsed buildings on the television, count the triangles, you see formed. It is the most common shape, you will see, in a collapsed structure. All these spaces are life saving.
Mind, next time when there is an earthquake, don’t duck and cover yourself under the object but just lay down by the object. Lets lean from CATS and DOGS and Babies who often curl up in the fatal position. We should too in an earthquake. Its natural safety instinct. We can survive in a smaller void, hence GET NEXT TO whatever is hard. If you are on the bed and the earthquake happens during night, just roll off the bed, a safe triangle will exist around the bed and not under the bed. If earthquake happen and you don’t get time to come out of building, just curl up and lie down next to sofa, chair or column. Never go to stairs, they have different ‘moment of frequency’ and are separated from the main building. Don’t venture inside the lift, it could land in crash. It is always advisable to get near to the outer walls of the buildings or outside of them if possible. People inside their cars are crushed when flyover above falls over their cars, so get out of your car and lie down aside the car, again the triangle will save you. Copp. has discovered while crawling inside the collapsed news paper offices and other offices with lot of papers that the papers don’t compact. Large voids are found surrounding stacks of paper. Large lives were found saved. Doug Copp’s theory seems working and so we must work on such practical experiences and develop SOP to identify intervention strategy in a considered way.
We have to learn from our failures. So we must understand our lessons from the earthquakes of India and Napal. We have to revisit our short term, middle term and long term strategy and our preparedness to ensure minimum damage to life, infrastructure and property. We need to take stock of our buildings, infrastructures, and other assets in an organized way and identify weak links. We will have to develop a standard operating procedure (SOP) to identify intervention strategy in a consolidated way. Broadly we must have to work on STS, MTS and LTS.
Short term strategy (STS): We need to communicate the masses in target areas initially in Zone IV & V and explain to them the need to stick to the norms of standard construction of earth quake resistant designs. People at large construct the houses with load bearing walls for their residential purposes, Detailed and exhaustive literature is now available for such construction and is uploaded on internet and EERI, earthquake advising sites.. They need to be read and followed meticulously for such constructions.
Middle Term Strategy (MTS): We need to have a look at the capacity to teach civil engineering at graduate level with quality input and in all probability it would need augmentation. Building bye-laws are to be modified as per the provisions of National Building Codes (NBC-2005). Engineers are to made accountable and as such Engineers bill is to be put on fast track and piloted in the parliament and get it through so that the structures be made by consulting the structural engineers. Ministry of Skill development should pay a pivotal role in imparting skill to labours and other workers for the safe construction of buildings.
Long Term Strategy (LTS): The research institutes have to look into contemporary work in the field of earth quake engineering in countries like Japan, America and other countries and catch up from that point elevate the level of Phd. Level in IITs and NITs so that the BIS (Bureau of Indian Standard) get adequate input in next few years to generate standards incorporating latest technology for adopting in construction and project management.
Further Research: Base isolation is one of the most popular means of protecting a structure against earth quake forces. It is a collection of structural elements which should substantially decouple a superstructure from its substructure resting on a shaking ground, thus protecting a building or structure’s integrity. Base isolation has potential to become one of the most powerful tools of earthquake engineering pertaining to the passive structural vibration control technologies.
These strategies have to be developed and the governments should work vigorously on these concepts but till then a well quote by Stephen Gardiner be remembered “Good Buildings come from Good people and all problems are solved by Good designs”.
(The authors are member of National Institute Centre of Earthquake Engineering (india) and (Computer Science Engineer)
Rabinder Shekher &