SEISMIC PERFORMANCE OF GOL GHAR

Abstract

Gol Ghar, a traditional oval-shaped stone-masonry structure with mud mortar, represents Nepal's vernacular architecture, shaped by local customs and terrain. While durable, these buildings are vulnerable to seismic activity. Despite their importance in earthquakeresistant construction, limited research has been done on their seismic performance, especially after the 2015 Gorkha earthquake, emphasizing the need for further studies. This research examines the seismic behavior, structural stability, and mechanical characteristics of structures through a combination of field and laboratory tests. Based on non-destructive testing, the compressive strength of the stone masonry was determined to be 2.75 MPa. Using a velocity meter, the building's frequency was measured at 7.38 Hz. To analyses the building, the frequency was matched with the building's predominant frequency by iterating the Modulus of Elasticity (E), which was found to be 140 MPa. The modal calibration has been done to matched frequency obtained from the ambient vibration test. Macro modelling of Gol Ghar was performed using nonlinear static analysis in the Abaqus to obtain the pushover curve. The performance points were determined using the response spectrum curve and the capacity curve, the performance point shifts to a spectral displacement of 10 mm, an acceleration of 0.49g, and a drift of 0.32%. For Failure mechanism Concrete Damaged Plasticity (CDP) criteria was adopted to obtain the damage pattern of the building. The Finite Element (FE) model successfully identifies damaged regions, anticipates the onset of collapse mechanisms, and estimates the collapse load at these points included separations of out-of-plane walls, failures of in-plane walls, shear cracks, and shear sliding failures. These results emphasize the seismic susceptibility of Gol Ghar, highlighting the necessity for enhanced construction techniques and measures to improve their resilience.