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“...KATHMANDU VALLEY AFTER GORKHA EARTHQUAKE 2015
S. Shrestha3’*, M. Reina Ortiz3, M. Gutlandb, R. Napolitanoc, I. M. Morrisc, M. Santana Quinterod, J. Erochkob, S. Kawane, R.G. Shresthaf, P.Awal8, S. Suwal h, S. Duwalh, D.K. Maharjan1
3 Carleton Immersive Media Studio (CIMS), Carleton University, 1125 Colonel by drive, Ottawa, On, K1S 5B6 Canada, sujan. shrestha@carleton. ca
b Department of Civil and Env. Engineering, Carleton University, 1125 Colonel by drive, Ottawa, On, K1S 5B6 Canada, Jeffrey. Erochko@carlet on. ca
c Department of Civil and Env. Engineering, Princeton University, E-208 E-Quad Princeton, NJ 08544, USA, rkn2@princeton.edu, imorris@princeton. edu
d Carleton Immersive Media Studio (CIMS), 1125 Colonel by drive, Ottawa, On, K1S 5B6 Canada, Mario.santana@carleton.ca eNepal Engineering College fBhaktapur Municipality gUNESCO Kathmandu Office h Khwopa Engineering College ‘National Society of Earthquake Technology
COMMISSION II
KEYWORDS: IT Documentation, Risk Preparedness, Nepal,...”
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“...well as technical and formal features identified during the course of the work, should be included. This record should be placed in archives of a public institution and made available to research workers.”
In the case of the Kathmandu Valley, recording and documentation of the cultural heritage are as important as any other phase of conservation, from the repair, to alteration, to intervention work. Without documentation, important existing character-defining elements of the structures, in both a visual and structural sense, may be lost during restoration. It is particularly important to document these buildings to both record them in the case of future disasters and also to be able to evaluate their performance in the previous earthquake and the likely performance in the future.
1.3 Part B: Structural Investigation
Historic building investigation is needed for acquisition of data related to material properties, construction techniques, hidden voids, inclusions, masonry and timber decay, ...”
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“...suspected to differ in construction technology from other temple plinths in the region. Because of this, the seismic influence of the plinth on the temple superstructure is not clear. Since there are many other monuments in the area that collapsed during the earthquake that also sits atop high-rise plinths, a better understanding of this particular plinth design and behaviour will contribute towards the conservation and restoration of those totally collapsed monuments.
In general, the workflow for carrying out this research project is divided into two parts as described previously: documentation and structural investigation. Many of these workflows were also applied to the evaluations of the other sites.
For recording and documentation of Nyatapola Temple, multiple digital tools were used. Recent developments in computer and information technologies have resulted in a wider range of options to document heritage structures with high precision.
The digital workflow used for field work was as...”
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“...no internal floors above the first-floor level forming open well type structure (Figure 9,10).
inwards from the level below, i.e., the outer edge of the upper wall is aligned roughly with the center of the wall below. The walls of each level were constructed just above timber beams. 3.2.2 Recording of existing damage condition
Major damage is concentrated in upper tier of structure and wall was found to be partially collapsed. The upper tier was recorded to be collapsed in previous 1934 AD earthquake as well and which is reconstructed later on. A major renovation was done during 1996 AD by Bhaktapur Municipality in which majorly roof was repaired wooden post in the upper tier was replaced after founding it was decayed (Figure 11) (Bhaktapur, 1998). This also suggests that there may be the presence of the timber element inside walls in below level as well.
Gauss: mean = 0.002941 / std.dev. = 0.004273 [4588 classes]
Figure 8. Ganss Distribution for cloud to cloud absolute distances
Figure...”
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“...in the doorway on all four-side wall also identified. High-quality orthophotos are generated from the close-range laser scanning and photogrammetric models. These orthophotos were used for mapping existing cracks in the wall (figure 12). Mapping of these cracks will then be introduced in the finite element modeling for assessing the existing performance of structure in future.
Figure 12. Mapping of existing cracks in structural wall
3.2.3 Geo- Radar Investigation
In addition to the surface documentation using laser scanning and photogrammetry, non-destructive techniques were used to investigate the inner composition of structural elements. For this purpose, geo-radar survey was conducted on the masonry walls (with a 900 MHz antenna) and plinth (with a 270 MHz antenna) of the Nyatapola temple. Georadar is a travel time tomography method that works by recording electromagnetic waves which are reflected at dielectric interfaces (different materials). Georadar allows the identification of morphology...”
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“...be used for further structural investigation of the seismic response of the temple.
Following the collection of geometric, morphological, damage, and other information on structural elements, a finite element analysis or combined discrete element analysis will be conducted to evaluate the seismic behaviour of the Nyatapola Temple in a separate study.
4. SCOPE OF ADDITIONAL WORK
In addition to the documentation and evaluation of Nyatapola Temple, the Carleton University - Princeton University team worked in collaboration with local Nepali colleagues to perform the following additional documentation and analysis work:
At Bhaktapur Durbar Square:
• Vatsala Temple - Georadar evaluation of the plinth structure to confirm excavation results, determine inner sanctum construction, and use this information to validate survey parameters (velocity and dielectric constant) and construction material reflections.
• Big Bell - Georadar evaluation of the supporting structure and photogrammetry.
At Dattatreya...”
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“... for the diagnosis of historic buildings: application at different scales (centres and single buildings). Proc of 4th international seminar on structural analysis of historical constructions, Padova, Italy. Vol. 1. 2004.
Colla, C., Das, P.C., McCann, D. & Ford, M.C., Sonic, electromagnetic & impulse radar investigation of stone masonry bridges, J. Non Destructive Testing and Evaluation International, Vol. 30, No. 4, pp. 249-254, 1997.
DOA 2015, Preliminary list of affected monuments by the Earthquake on 25 April 2015, Department of Archaeology, Nepal.
ICOMOS, 1965. International charter for the conservation and restoration of monuments and sites (The Venice charter 1964). International Council on Monuments and Sites.
ICOMOS, 1996. Principles for the Recording of Monuments, Groups of Buildings and Sites (1996)., (October).
Shrestha, Sukra S., 2005. Research Note Work Index ofNytapola Temple. Contribution to Nepalese study. Vol 32. No. 2. 267-275
Schuller, Michael P., 2003. Nondestructive...”
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