Nonlinear Reliability Assessment
of Cable Members in Cable-supported Bridges
Jin Ho Lee
Bridge design concept is changing from Allowable Stress Design(ASD) concept based on empirical design to the Load and Resistance Factor Design(LRFD) concept based on a probability-based reliability analysis. At this time, studies for cable bridges design guideline is in progress according to ta rise in freight traffic. For the reliability based design concept, there should be reliability assessments of cable bridges in the present design concept. And a new target reliability level should be decided by these assessment sources so that new load and resistance factor will be generated in satisfaction with the reliability level. But assessment of cable bridges in home is not enough for this, and this limit of the evaluation experience is serious especially for cable elements which are non-existent in general bridges.
Structural system is being assumed as a linear system for cable elements to apply LRFD concept because structural system of cable bridges is non-linear so that reliability assessment of cable bridges is so complex that reliability analysis tools for these are not debeloped yet. But more exact analysis should be required to reflect non-linearity. And target reliability level should be decided by this experience for the design of long-span cable bridges.
So reliability assessment of a few cable bridges in home is conducted by reflection of structural non-linearity, and compare with the results by assumed the structural system as a linear system. And a proper reliability level would be drawn by these results, and load and resistance factors also would be extracted.
Long-span cable bridges, Cable, Reliability, Reliability analysis, Nonlinear analysis, Load and Resistanc Factor Design, Target reliability index, Resistance factor