Seismic performance of a heritage rubble stone masonry building—a case study

Abstract

The old masonry buildings in India are terribly vulnerable to lateral loads especially the buildings lying in the high seismic zones of lower Himalayas. This paper deals with evaluation of the seismic performance of an old unreinforced rubble stone masonry building situated in Uttarakhand. CSIR-CBRI conducted a study on the structural soundness of “Pant Sadan,” the official residence of the Chief Justice of Uttarakhand. After a preliminary survey of the building, architectural plans of the building were developed. A finite element analysis was performed using commercially available SAP2000 software. Linear and nonlinear analysis is performed to assess the present strength of the old structure by computing different stresses in the building under earthquake load. In the modeling, it is assumed that the masonry structure is homogeneous and the material behavior is nonlinear. Subsequently, the static analysis results (stresses) are compared with the values given in masonry code (IS 1905:1987). Pushover analysis and time history analysis for Uttarkashi earthquake (1991) is also performed to assess the performance of building under a Himalayan earthquake. The analysis results show that building response is satisfactory under vertical loading and shows some weak zones for the previous seismic activities. The results of the finite element modeling will help to predict the local and global collapse mechanisms and will reduce the seismic risk by adopting the proper retrofitting strategy.