Seismic Investigation And Vulnerability Analysis Of Nepalese Cultural Heritage Buildings Induced By Gorkha Ms 8.1 Earthquake

Nepalese cultural heritage buildings built in ancient time are monumental structures with the cream of local architecture,historic and archaeological importance,and they have high value of scientific study.Brick-timber structure is the major structural type in Nepal.However,Gorkha earthquake has shown potential damage of brick-timber structures,and it is now an essential issue to evaluate their seismic safety for future earthquakes.At first,analysis has been done to the seismic damage of Nepalese brick-timber structures in Gorkha earthquake on April 25,2015,and the typical seismic damage such as wall destruction,wall cracks,wall corner damage,wooden components destruction,tilt and collapse has been studied.Meanwhile,the seismic damage degree of cultural heritage buildings is defined,and different examples of damage levels are obtained.Secondly,considering seismic damage mode of Nepalese brick-timber structures and characteristics of the local ground motions,a 300-year-old Nepalese brick-timber structure with two-stories is studied with the dynamic incremental analysis.Result show that,the inter-storey drift corresponding to immediate occupancy,life safety and collapse prevention are 0.06%,0.32%and 0.44%,respectively,then,the seismic damage degree is quantified.Finally,based on fragility curves of Nepalese brick-timber structure with two-stories under these two different ground motions,study indicates that the damage probability of immediate occupancy is higher than the probability of life safety and collapse prevention.However,a small increase in PGA can make structure collapsed when structures reach or exceed the limit of life safety.Moreover,the damage probability of the three limits under pulse-like ground motions higher than the non-pulse-like ground motions is about 18.9%,14.3%and 12.6%,respectively.Compared with the non-pulse-like ground motions,pulse-like ground motions has some effects on the seismic performance of Nepalese brick-timber heritage structures.In summary,according to the typical seismic damage mode,equivalent frame model established and seismic vulnerability analysis of brick-timber structures under different ground motions by means of IDA is studied,which can provide a reference for the seismic performance of Nepalese brick-timber structures.