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

proposal developed in the US proposed a fairly massive
reinforced concrete frame inside of the temple, as
an exercise exploring how close a retrofit might come to
meeting International Building Code standards. There
was some acknowledgement by the designers at the time
that this frame was probably too radical an intervention,
requiring substantial dismantling of the historical building
to insert the rigid frame structure. Meanwhile, for
the Narayan temple, strengthening measures along similar
lines, an inserted rigid frame in steel with a massive
foundation pad deep in the earth, were proposed.
Review of the 18th c. Narayan temple by engineers revealed
that the building was in critical need of reinforcement
to improve performance in the next earthquake.
In addition to the general issues of roof cover and timber
structure deteriorated by the elements, this analysis
focused on its vulnerability due to its top heavy tiered
roofs and its high center of gravity relative to its slender
proportions and raised plinth. In the wake of suspended
discussions for the Indrapur Temple reinforcement
scheme, this proposed reinforcement work was not accepted
for implementation. The decision followed the
conservative position of the Department of Archaeology,
which both did not consider seismic reinforcement a
desirable or critical component in conservation projects
and enforced a blanket prohibition on the introduction
of reinforced concrete and steel framing. The decision
prevented the reinforcing that would have reduced damage
to the temple, which suffered heavily in the 2015
earthquake. (The new Guidelines, currently under review
by the National Reconstruction Authority, offer a
more moderate standard which, if adopted, would allow
for a better outcome today.)
Matthias Beckh, a structural engineer from Silman’s office,
came to Nepal, volunteering to oversee the work on
site, based on the knowledge that site supervision and attention
to details for the reinforced concrete work were
critical for such interventions (rebar layout and connections
needed to be fastidious). He also came in order to
try to ascertain on site through small scale probes more
critical information about the existing foundations. This
information would be necessary to assess Silman's proposed
designs.
While developing the proposals, KVPT held parallel
discussions with the Dept. of Archaeology to secure
their approval for the technical solutions proposed for
Indrapur and Narayan. For purposes of presentation, a
variant of the Indrapur design - simplified, smaller, and
easier to retrofit - was developed by Ranjitkar for review
by the Department. This downsized solution avoided
the dismantling of the upper floor necessitated by the
Silman scheme, and allowed the new structural members
to be less intrusive in the sanctum. This process went
on for three months. At each review by the Department
and Steering Committee, the introduction of reinforced
concrete - even though concealed - was flatly rejected.
The justification by then Dept. Director General was
explained on the basis of Unesco’s general prohibition
of the use of cement mortar in the Monument Zones.
This put us in a dilemma. Our international funding
and donors expected a model project, and the time and
research and money invested was already a large output.
Moreover, the Trust was convinced the use of reinforced
concrete in the foundation was the appropriate solution,
based on thoughtful precedents. Our engineer developed
a solution which could be implemented in the
course of a weekend, and we planned a temporary fence
and a continuous installation period over one weekend.
The new scheme was essentially a reinforced concrete
girdle to be developed around the perimeter trench of
the plinth, - an improvised solution. We went ahead
and implemented a variant of the scheme based on the
limited time of the supervising engineer. This variant, a
girdle-like ring beam wrapping the plinth foundation,
was an intriguing solution because it provided protection
with very little damage to or infringement of the
building fabric. This underground perimeter girdle was
complemented by the myriad of smaller scale solutions
Indrapur and Narayana Temples
Top to bottom:
Ca. 1930, after 1934, 2000, 2002.
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