Are high rise (apartment) buildings
in Kathmandu Valley earthquake proof?
One of the questions after
the 7.9 and 7.3 earthquakes of April/May 2015 is whether the high rise
buildings that have been constructed in Kathmandu Valley are safe
enough.
The answer is that
some of them certainly are not and from most of them it is uncertain
whether they will be strong enough to withstand a 8.5 to 9.0 earthquake.
But given the fact that many high rise buildings already suffered a lot
of damage after the 7.9 earthquake some 80 kilometers outside Kathmandu
most high rise buildings probably won’t be strong enough to withstand a
much more powerful earthquake.
It is questionable whether
building guidelines have been followed correctly.
Herewith a video of a modern building of only 7 stories which was
not strong enough to withstand the 7.9 earthquake of April 25.
And a video of the state of
several apartment buildings after the 2015 earthquakes.
There are some voices saying it might be wise to
limit the height of building to only a couple of stories. Maybe a
limitation of three floors is a little bit too strict, but for sure
smaller buildings will be safer for the inhabitants of the building
itself and its surroundings. Such buildings will be less likely to
collapse during a very powerful and/or long-lasting earthquake and if
they do, the chances are higher that all people get out before it
collapses and the amount of rubble will be smaller and less likely to
bury other buildings in the neighborhood.
In the mean time we advice
(future) residents of high rise buildings to thoroughly check whether a
building is considered to be safe enough or not. In case of any doubt,
don’t buy or rent an apartment of office spaces in such a building.
Besides that it is better to avoid older unsafe buildings especially
when they are 4 to 10 stories
high (f.e. in the Old Town, Gongabu,
Baleju and similar areas full of unsafe buildings).
Owners of high rise buildings might have
their buildings checked by foreign (f.e. Japanese) and unbribable
engineers or the government should create other reliable ways of
certificating safe high rise buildings. It is most likely that many of
the current building will fail to pass.
Apparently the Nepali Government is not sure
about their building codes as it has
imposed a 2 month ban on house design approval and
is working on
stricter building codes and better monitoring / enforcement of those
codes.
It is very sad the Nepali Government and many Nepali people "needed"
such an earthquake before revising the building codes and construction
manners as it was known for many years that a lot of buildings would not
be able to sustain an huge earthquake.
