The 7.6 intensity earthquake in Kashmir causing extensive devastation has once again exposed the stone based technology in construction in the quake prone mountains and compelled to evolve some better alternatives. The dangers of using stone in the walls of the houses is fraught with grave risks ,particularly in the quake prone areas .It was observed in context of the Gujarat quake that the maximum damage was caused by the crumbling stone walls. The rural structures had all crumbled for which the C class construction using earthen mortar with stone was blamed, but even the A class urban structures did not stand wherever stone was used; as stone has lesser area in contact with the mortar, its size is much bigger and it is much smoother than the brick; so it gets loose and detached easily and immediately and because of higher mass gathers greater momentum , leading to the fall of stone walls. Moreover, the great momentum with which the stones come rolling down has to be seen to be believed. In a building at Anjar in Gujarat, the deadly rolling stones knocked down the column supporting the staircase that ultimately led to the fall of that part of the building. In hills most of the structures are single storeyed, but stone the great villain, used in construction of the walls makes them vulnerable and causes all-round destruction.

The loss in POK is immense both in terms of human life and the buildings, but it is quite considerable in India also. The damage to houses is quite widespread and requires rebuilding that too at the earliest. Since altogether new constructions will come up, we should ensure that these are quake resistant and damage proof during quakes. The use of stone should be avoided in order to ensure that the structure should not crumble and fall. It is possible to have such structures, that too at affordable prices, by adopting the technology used by the Haryana Police Housing Corporation in 2002-3 under the author in constructing model barracks for Police force on duty in Chandigarh at the official residence of CM Haryana .The technology is an extension of Assam type constructions and was thought of and perfected while he was on rehabilitation mission in rural areas of Gujarat after the 2001 quake, though it was experimental stage and no such structure could be raised at that time. It was left to raise a temporary stores building at Panchkula and the technology was put to real test at Chandigarh in CM`s residence only. These structures on MS steel pipe frame have RCC double wall and CGI sheet roofing as detailed in the subsequent paragraphs.

The structure has columns of MS steel pipe 2”X2” square. These are embedded in the RCC plinth beam laid horizontally along the foundations of the building. Steel pipe horizontal tie beam would run at the top of the columns and connect them. The trusses will rest on the joint of this pipe and the column. All the members of the frame are either welded or joined with nuts and bolts firmly to make it a single integrated structure along with the plinth beam. This single mass may tilt under the heavy shock, but it would not bend, break or crumble. Columns could be as high as required, but not more than 10ft., placed at a distance of 10 to 12 ft. from eachother. This span of 10 to 12 ft, could be divided suitably by fixing such number of horizontal and vertical members as are considered necessary to divide it into equal spaces so that specially prefabricated RCC wall panels could be screwed into the frame to form the wall. Some such spaces could be converted into doors and windows.

Walls constitute most of the weight of any building and as such are the most critical item in any building in context of the earthquake. In the proposed structure there will be a double wall with two-inch air pocket in between. The thickness of each of the two walls would be ¾ inches. Thus the composite wall with air pocket would be 3.5 inches thick. For wall panels expanded metal of the requisite size would be enclosed in a frame of steel flat so that at its ends it is held firmly. The expanded metal would be out of 2mm thick steel with gaps of 20mmx20mm. Two walls with gap in between will ensure that the heat and cold from outside will not be able to penetrate. Cast out of very rich (1:1.5:3 ) concrete, each of the two walls is quite strong and would compare well with the conventional brick wall, though it would be very low in weight and would provide thermal comfort that no other technology can match. In this way the Weight of the walls is drastically reduced by 80% or so. That by itself will prevent loss to a very large extent as collapsing slabs only crack or bend at one or two places, whereas the crumbling walls by and large cause all the damage. Further experiments were underway to fit such walls into the multi storied structure on RCC columns and beams when the author retired .

In plains we are using ACC sheets for roofing, but in these snow prone areas CGI sheets would be a must. Besides, a false ceiling of plywood or some other suitable material would also be necessary to protect the house from heat and cold from above.

Such structures that the author raised in 2002-3 are doing very well. The Haryana Police Housing Corporation is constructing more such structures for CISF at Chandigarh itself at a cost of about Rs. 200 per sft.only. Cost, no doubt, would rise in mountains on account of transport, for bringing skilled labour from outside as also on account of some special specifications that may be required in this area. However the stone material and sand would be locally available, so the escalation should not be very high. Say we could presume a rate of 250 per sft. If area of a dwelling unit on the average is to be 1000 sft., a house may cost about Rs.2.5 lacs or around that only. It is a permanent construction and unless the steel is allowed to rust, it may last no less than the regular construction. If locally timber is available, the structure could stand on that as well.
This technology can be utilized with advantage in Kashmir .The houses will also come up very fast. Actually during winters no construction can be started in snow prone areas before March 15.Contracts can be finalized in the meantime, the steel can be procured , fabricated and transported to the nearest base camp so that construction can commence in March in a big way without any loss of time. However if any works are required in non-snow prone area, the same can be taken up immediately. The four summer months should bring general relief on housing front to the unfortunate victims. One-lac big houses covering 1000 sft. each, with all the facilities, may cost something like Rs. 2500 to 3000 crores only.

B R LALL
The author is a retired IPS officer who also served as Chairman Shivalik Development Agency and CMD Haryana Police Housing Corporation.

The views and facts stated above are entirely the responsibility of the author and do not reflect the views of this Association in any manner.