Post-Nepal quake, concern over structural safety of buildings in rehab colonies

The residential and commercial buildings in sectors, however, are relatively much safer as these had been approved for structural stability by the engineering wing of the estate office.

A study conducted by the Chandigarh Administration with the help of PEC university’s technical team during the preparation of the Master Plan-2031 has pointed out that a large stock of non-engineered buildings in Bapu Dham Colony and Sector 25 rehabilitation colony has been constructed without following proper structural stability norms.

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Such aberrations are a cause for concern for the local administration since the city falls within the high risk-prone seismic zone wherein special measures need to be taken to help the buildings withstand earthquakes.

These are not the only two examples quoted in the study. The recently notified Master Plan-2031 has suggested a structural audit in over a dozen rehabilitation colonies, peripheral villages, Manimajra and even cheap houses constructed in several sectors where quite a number of houses have been constructed against codal provisions.

STRUCTURAL LAPSES IN ABUNDANCE

AS per the study, a large number of buildings in these two colonies were designed and allotted as single-storeyed but over the years these have gone up to three-storeyed and even four-storeyed in some cases without following the structural safety norms and provisions.

Due to the uneven height of the three- and four-storeyed structures, large bending moments and sheer forces have developed at the base, which is dangerous at the time of quakes. Vertical alignment of the walls is not proper.

A major cause of worry is that masonry columns are taking load of upper floors without any foundation. Due to lateral movement of the ground during the seismic activity, the column can become critical, the study has pointed out.

Besides, staircases in several houses are resting on cantilever slab which is not desirable, the study has pointed out and added that load-bearing masonry walls of upper storey are not properly placed above the masonry wall of the storey below, which is not a proper structural arrangement.

Former UT chief architect Sumit Kaur, who played a vital role in preparation of the Master Plan, said that it was a matter of grave concern that despite the city having strong building bylaws, there was such a high level of structural lapses.

“Due emphasis has been laid on this problem in the Mater Plan. We need to identify each and every house with such lapses and then make them structurally safe so that in adverse circumstances, human loss is minimum,” she said.

City-based architect S D Sharma said there were many ways of strengthening the existing buildings but the first job was to identify buildings with weak structures.