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I recently visited a residential building, located in Kehal area of Abbottabad. The visit was made to visually-inspect the building in order to ascertain if the building sustained any structural damage due to the 7.5 magnitude earthquake that jolted many parts of the country on 26th October 2015. The structure is a single story stone-masonry building with mud plaster on walls. The roof of the building consists of wooden rafters, purlins and C.G.I sheets. I am attaching photos to show you the damage sustained by the buiding due to the seismic event of 26th october.

Here are my two cents: Steel structures are comparatively easier to retrofit. However, you will have to determine - the locations where you need strengthening, - how much strengthening is required? - how this can be done? - whether it is economical (as compared to complete replacement)? , and - will the structure, in retrofitted form, be visually acceptable? This can be done by modelling the existing structure in ETABS or SAP2000 etc., using member section properties as per actual section sizes, and a suitable steel grade (using best and safe judgement, based on quality and physical condition observed at site). Apply all applicable code requirements (as per IBC, AISC, ASCE etc,) and observe stress levels of various members. Now, after saving the model with a new name, upgrade all the failing members with larger or alternate member sizes (to which these can be replaced or upgraded by structural additions/modifications). Comparing the results of the two structural models, mentioned above, will give you a clear idea about where the retrofitting is required, and to which extent. In case (after the above analysis, and working out relative costs), it is determined that retrofitting will be economical (rather than complete replacement) and visually acceptable as well, it (retrofitting) may involve replacement of or additions/ modification to various existing members. Required connections may be made using welding or bolting, whichever is appropriate. Regards.

The only thing that stands between an earthquake and public safety is a structural engineer. We need to empower our engineers with the skills and tools that allow them to design ductile systems. For that reason, I request everyone to please encourage other to be a part of SEFP and be more active. It is the only structural engineering platform for Pakistan and Pakistanis. Lets get the best out of us. Thanks.