NEW MODEL CODE: PRACTICAL IMPLEMENTATION IN SEISMIC ASSESSMENT OF EXISTING STRUCTURES

Current codes of assessment of existing structures (EC8-III and FEMA 356 / ASCE/SEI-41) compare deformation capacity of the individual structural members with the corresponding seismic demands. In this field the greatest uncertainty is with regards lightly reinforced concrete (R.C.) members. Comparison of the estimates obtained using current Assessment Codes with test data illustrate poor predictive capability by the code equations. A more consistent approach associates deformation capacity with the weakest mechanism of member resistance, identified through consistent prioritizing of the competing modes of failure. The revised expressions introduced by the New Model Code are incorporated in this assessment framework for the separate mechanisms of resistance. The resulting mechanistic procedure is evaluated against Assessment Codes by comparing results of these approaches for a series of lightly R.C. columns tested under reversed cyclic load.