KVPT’s Patan Darbar Earthquake Response Campaign - Work to Date - September 2016

Early schematic design discussions for this project represent
a structural philosophy of creating a very stiff core
that inhibits movement of the superstructure (building
above ground level). This core would be designed to absorb
the lateral forces of the earthquake, creating a strong
load path pulling the loads from the upper building elements
down to the foundation, thus limiting movement
of the building and providing a more stable structure.
This would be considered an operational building performance
level and would require strong materials like
steel to create a moment-resistive or braced frame system.
This first approach ended up raising what is inherently
one of the first big questions in seismic preservation engineering:
What level of building performance is desired,
and how will that affect the fabric of the building? Prior
to the earthquake, KVPT had typically designed to life
safety performance, using a myriad of smaller measures
that took into account how the seismic measures would
affect the historic architecture.
In the context of the Manimandapa, the engineer’s
question becomes: Is a system desired that achieves an
operational or occupiable level, meaning that the structure
will be strong enough to suffer little to no structural
damage during a major earthquake? This type of system
would require more modern materials and more stringent,
complicated structural details, and would change
the historical fabric more. Or is a more subtle system
desired that leaves the traditional architecture more intact,
at the risk of having a structure that is stable enough
to protect life safety but would suffer moderate to significant
damage in a large earthquake? For the Manimandapa,
introducing a stiff steel core and tying the
structure to this core could achieve an operational level
of building performance, but this would require steel
columns or bracing that visibly modify the open timber
arcade of the ground floor.
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