Argumentation of a formula for numerical assessment of earthquake-resistance shortage of buildings using nonlinear static pushover analysis in SAP2000

The article is a continuation of research previously published in the Bulletin (2021, vol. 21, no. 2). Author offers explanations and clarifications of a formula proposed to assess insufficient earthquake resistance shortage (hereinafter Id) of buildings using calculation procedures of nonlinear static Pushover analysis in SAP2000. An idea was implemented to graphically justify the mathematical expression used to determine Id with building age adjustments per building age. It was assumed that under certain conditions a change in service life-span (hereinafter referred to as Tst) of a building will lead to changes in the calculated acceleration of vibrations in proportion to the cube root of Tst. It was also assumed that at the end of a building's service life an earthquakes, can cause severe structural damage (or destruction) of its members, can occur. Change of a building age by estimation time of Id value was assumed to be distributed according to an exponential law. A value corresponding to the end of the building's service life Tst was taken an objectivity compliance criteria for the proposed formula for estimating of Id. Obtained an Id value should be confirmed by technical survey of buildings in seismic areas. Relationship curves of Id (Tst) were plotted according to a refined formula for the considered territory tremor values and earthquake waiting time. The obtained results can be applied to fulfill the requirements of term 6.19.11 of Seismic Design Building Code SP 14.13330.2018 and to be used as a supplement the calculation provisions laid out in the Assessment Procedure for Survey of Standard Buildings to Determine their Earthquake Resistance and Need for Seismic Retrofitting (Kamchatgrazhdanproekt, 2009).