Hits:

Indexed by:会议论文

Date of Publication:2014-08-20

Included Journals:EI

Abstract:Fiber reinforced polymer (FRP) composites have been regarded as desirable engineering materials for seismic retrofit of reinforced concrete (RC) structures. The term of collapse margin ratio (CMR) addressed in ATC-63 report has provides a practical mathematical tool to quantify the safety margin of structures under strong ground motions from the level of the maximum considered earthquakes (MCE) to that corresponding to collapse state. This paper presents a new CMR-oriented seismic retrofit philosophy for concrete structures with fiber reinforced polymer (FRP) composites. The pushover analysis method (POA) has incorporated into the philosophy in which a modified macro-level global seismic damage model used to identify the critical collapse state of concrete structures. OpenSees program is applied to implement the suggested nonlinear MPA procedures. The confined concrete CC01 material model in OpenSees is modified to reasonably reflect enhancement in the hysteretic properties of concrete columns due to the combined confinement mechanism from lateral reinforcement and wrapped FRP composites. Such enhancement is demonstrated through an example planar concrete structure frame designed in accordance with current Chinese codes. As expected, the results from the example frame indicate substantial mitigation of collapse risk because of significant enhancement of ductility in concrete columns.