Nonlinear Static Analysis and Evaluation of an Existing Structure

Abstract

A seismic evaluation was performed to an existing structure in the city of Carolina, who is a municipality located on the northeast coast of Puerto Rico. It is a concrete structure of two levels with a lateral resistance system Special Reinforced Concrete Moment Frame in both directions. The structure was evaluated in different ways, the main evaluation is an iterative Non-linear Static Analysis. We performed this analysis using geometric nonlinearity "P-∆" included in ETABS program and the materials nonlinearity using constructive equations of concrete and steel to create the curve moment versus curvature for each element. An evaluation of the seismic details requirements was performed by comparing the ACI 318-95 code designed with the current code ACI 318-14. We also evaluate using the ASCE 41 and FEMA 356 code for existing structures using a Static Nonlinear Analysis "Pushover". As a result, the structure meet the demand of the Static Nonlinear Analysis, but did not comply with the requirements especially seismic shear reinforcement and joints shear. ASCE 41 evaluation comply with the performance determined which is not necessary structural retrofitting and post-earthquake the structure is capable to resists gravity load in service. Key Terms - Nonlinear Static Analysis, Pushover Analysis, Seismic Evaluation Procedure, Structural Design Codes.