Beam Bridges Reliability Assessment considering Moment-shear Coupling Effect

Abstract:

Beam bridges in the operation bear both moment effect and shear effect at the same time, and their moment and shear resistances also affect each other. The assessment of existing Beam bridges needs to consider moment-shear coupling effect. The resistance and effect variables were expanded from unary random variables into binary random variables in the paper. Based on the modified compression field theory (MCFT) adopted in AASHTO LRFD design specification, the probability models of moment-shear coupling resistance and effect were established. A new reliability assessment method was proposed to consider moment-shear coupling effect. The example analysis shows that: for the cross-section bearing both larger moment and shear effect component, the failure mechanism is the moment-shear coupling failure, the traditional method results in unsafe conclusion, and it is necessary to consider the moment-shear coupling effect during reliability assessment.