Nonlinear Static Analysis Procedures for Seismic Performance Evaluation of Existing Buildings - Evolution and Issues

For a quick performance evaluation of existing buildings under an anticipated ground shaking, the nonlinear static analysis procedures (NSPs) are always an attractive option for practicing engineers. Compared to these NSPs, the detailed nonlinear response history analysis (NLRHA) for a sophisticated 3D finite element model requires far more computational and modeling effort. Sometimes the seismic performance evaluation of a large number of buildings is required in order to assess the seismic vulnerability and loss estimation for a particular study area. The applications and relative accuracy of various available NSPs become even more relevant in such scenarios. Over last several decades, the NSPs have passed through a series of proposed modifications and improvements which kept the interest awakened among practicing engineers and academicians. This paper is a review of all such improvements and provides a brief account of various approaches in the NSPs, their inherent assumptions, sources of uncertainties, limitations and associated challenges.