Damage survey, vulnerability assessment and retrofit of a residential building in Nepal

The “Downtown residential complex” consists of two towers of 15 floors each resting on a common underground basement. The “Downtown complex” was in an advanced construction stage at the time of the 2015 Nepal earthquake and suffered damage to either structural and nonstructural elements.

In September 2015, Numeria was requested by the building owner to carry out a damage survey. In order to determine the dynamic characteristics of the buildings, a set of instruments have been installed, under Numeria supervision, by the Seismological Research Centre of the Italian National Institute of Oceanography and Experimental Geophysics for the acquisition of accelerometric data, while estimates of site amplification of seismic ground motion have been obtained from application of HVSR technique.

Following the survey, Numeria has been asked to carry out a vulnerability assessment and propose solutions for seismic retrofit. Based on the results of site monitoring, retrofit interventions forseeing the insertion of energy dissipating devices have been designed by Numeria

The April 25, 2015 M 7.8 Nepal earthquake, also known as the Gorkha earthquake had his epicenter approximately 80 km to the northwest of the Nepalese capital of Kathmandu.  A number of buildings also located in the so called Kathmandu valley and designed according to the current Nepal National Building set of codes were damaged.