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“...Damage Assessment of Cultural Heritage Structures after the 2015 Gorklia, Nepal, Earthquake: A Case Study of Jagannath Temple
Sujan Shrestha,a) Bipin Shrestha,b) Manjip Shakya,c) and Prem Nath Maskeyd)
The Gorkha, Nepal, earthquake and the series of aftershocks that followed have damaged many heritage structures in and around Kathmandu Valley, including UNESCO World Heritage Sites (WHSs). This paper summarizes observed damage to the heritage structures of diverse typologies within the UNESCO WHSs of Kathmandu Valley. As a part of the investigation, inspection survey and damage assessment were carried out for Jagannath Temple, one of the partially damaged monuments in the Kathmandu Durbar Square WHS. .Ambient vibration and in-situ tests using the pendulum hammer, the rebound hammer, and in-place push on masonry walls were performed. Finite-element models of the structure were developed, and the results were analyzed and compared with field observations. Based on the observed damages and...”
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“...outer layers of masonry walls, and failure of timber connections. Such damage can trigger the sudden or brittle collapse of a masonry structure with very little warning. For effective restoration and conservation of any historic building, a detailed assessment of the structure and of the physical damage to its masonry is required, for which a deep knowledge of actual internal construction, geometries, materials, morphologies, and mechanical properties is necessary.
Table 1. Damage states in the seven Kathmandu Valley World Heritage Property monument zones
Monument zone Number of classified monuments Number of totally collapsed monuments Number of partially damaged monuments
Hanuman Dhoka Durbar Square 97 11 39
Bhaktapur Durbar Square 39 5 14
Patan Durbar Square 44 6 21
Changunarayan 67 3 2
Pashupati 44 6 21
Swayambhu 82 4 9
Bauddhanath Partial damage in stupa...”
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“...DAMAGE ASSESSMENT OF CULTURAL HERITAGE STRUCTURES: JAGANNATH TEMPLE
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In this paper, a brief description of the architectural features of these buildings and their seismic performance during the Gorkha earthquake is provided. Finally, a case study of the Jagannath Temple is presented, which includes investigation of the structure, in-situ testing, and analytical modeling.
HERITAGE BUILDINGS OF THE KATHMANDU VALLEY
The cultural heritage buildings in Kathmandu Valley can be classified into three categories: tiered temples, shikhara temples, and stupas (Tiwari 2009, Korn 1976, Dangol 2007).
In general, the tiered temples of Kathmandu Valley are square in plan, with two or three tiers. Only two four-tiered and two five-tiered temples exist in the valley (Tiwari 2009). Large temples with two or more tiers are usually constructed with two core walls surrounding the sanctum core (Tiwari 2009) (Figure 2a). The walls are constructed as a composite of interior kiln-fired rectangular bricks and...”
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“...in the mortar, only in the top of the structure, might have triggered the incompatibility between the old and new materials, perhaps resulting in in the structure’s incompatible local responses and ultimately leading to its sudden failure in the Gorkha earthquake (Figure 6) while other similar structures nearby suffered only partial damage.
Damage to structures resulting from similar restoration work was also observed in Pratappur Temple in the Swaymabhu monument zone (Figure 7a). The superstructure of the temple above the plinth was restored completely using a mortar of lime, brick dust, and sand in 2011. During the recent earthquake, it suffered severe damage in the connecting...”
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“...S368
SHRESTHA ET AL.
(a) Typical section (b) Overturning of walls (c) Failure of the tip
(d) The collapse of the walls (e) Total Collapse
(a) Improper connection
Figure 5. Wooden elements in traditional structures.
Figure 4. Damage to Shikhara temples.
(b) Decayed floor joists and wall plates...”
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“...DAMAGE ASSESSMENT OF CULTURAL HERITAGE STRUCTURES: JAGANNATH TEMPLE
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Figure 6. Vatshala Temple, Bhaktapur Durbar Square before and after earthquake.
(a) Crushing of old brick work in (b) Timber/clay tile roof of structure replaced with
Pratappur temple concrete roof
Figure 7. Damages due to variations in material integrity during restoration work.
portion of the old and new construction, resulting in the crushing of old brick work around the circumference. In contrast, the Anantapur Temple, with almost the same configuration in the same locality and which had never before been restored, experienced partial collapse at the top and shear cracks in the ground wall. It is worth noting that, in the first case, the compatibility of materials in restoration work was at issue whereas at .Anantapur lack of proper monitoring and maintenance, along with the age of the structure led to the damage. In some cases, timber and clay tile roofs were replaced with concrete, adding substantially to the...”
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“...were restored completely, and some repair work in the wood-crafted elements was carried out (KVPT 2000).
After the 2015 Gorkha earthquake, a comprehensive visual damage assessment of the temple was prepared, as shown in Figure 9a. It was found that two types of mortar (lime and mud) had been used during reconstruction in 1935. Most of the ground floor brick walls were built up with lime mortar (Figure 9b), whereas the first-floor brick walls and top-floor walls were constructed with mud mortar. The top-floor masonry wall was heavily damaged, with significant diagonal tension shear cracks through the brick and mortar (Figure 9d). All four walls of the top story experienced out-of-plane deformations (Figure 9c) with a maximum deflection of 45 mm. There were minor cracks in the inner wall of the first floor, but no significant damage was observed in the ground-floor walls. It was not possible to inspect the condition of the embedded timber elements inside the masonry walls.
To assess the condition...”
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“...DAMAGE ASSESSMENT OF CULTURAL HERITAGE STRUCTURES: JAGANNATH TEMPLE
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Undamaged Partially damaged Heavily damaged
(a) Damage grade of structural wall
□ Limo Surkhi Mortar
Ground Floor Plan MudMonar Jagannath Temple
Second Floor Wan Inclination Jag&nnath Temple
(c) Inclination measurement of top floor wall
(b) Different composition of masonry wall
(d) Damage in upper wall
Figure 9. Condition assessment of Jagannath Temple.
NUMERICAL MODELING
To evaluate the response of the temple during the Gorkha earthquake, finite-element analysis was performed in SAP 2000 (v. 16.0.0). Given the limited knowledge of the temple’s material characteristics, nonlinear analysis of the masonry was out of the scope of analysis. In this study, the structural component materials were assumed to be homogeneous, isotropic, and linearly elastic. The masonry wall was modeled using solid elements, and timber elements were modeled using frame elements. In total, 1,890 solid elements and 784 frame elements were used...”
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“...DAMAGE ASSESSMENT OF CULTURAL HERITAGE STRUCTURES: JAGANNATH TEMPLE
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(a) First mode (bending along X-axis), T=0.219sec; f= 4.55Hz
X S33 Contour! (IQX)
__________________________________» } ■» jolOB-l -[[H.mm.C u|
(c) Direct normal stress S33 in +EQX loading
(b) First mode (modified) (bending along X-axis), T=0.337sec; f= 2.96 Hz
-. M3 Contour! IKJX)
_______________________________________» I ■» |aioe»i jJ|kn,«,c xl
(d) Direct shear stress S23 in +EQX loading
JSC S33 Contour! (IQX)
$= | 4 iGLOE-L <•; c, C
(e) Schematic diagram of timber confinement (f) Direct normal stress S33 in +EQX loading
in inner wall (with additional timber element)
Figure 10. Numerical analysis results....”
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“...thus that timber bands in the masonry inner wall of the temple (Figure 1 Of) is a possible approach to minimizing damage in a future earthquake.
CONCLUSION
This paper presented details of the damage to various heritage structures observed after the 2015 Gorkha earthquake. Vulnerabilities of the heritage structures to strong ground shaking were noted, and it was observed that the damage patterns were difficult to generalize because they could be quite different in heritage buildings with similar architectural features. Moreover, damage to some of the buildings was exacerbated by inappropriate interventions, insufficient details regarding timber elements in rebuilt structures, and lack of maintenance.
A case study using the Jagannath Temple was presented. To assess the condition of the temple’s masonry walls, limited field tests were conducted. A three-dimensional numerical model of the temple was developed in SAP 2000, and linear static analysis was carried out. The numerical evaluation revealed...”
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“...DAMAGE ASSESSMENT OF CULTURAL HERITAGE STRUCTURES: JAGANNATH TEMPLE
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“...RILEM, 1998. Determination of masonry rebound hardness, Recommendation MS. D.2, Materials and Structures 31, 375-377.
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