Seismic Reliability Analysis of Cable Stayed Bridges Against First Passage Failure

摘要: In many structural applications, the ultimate purpose of using stochastic analysis is to determine reliability a structure, which has been designed withstand random excitations. The present study concerned with one failures, are results dynamic response stable cable stayed bridges. If Y(t) (either deflection, strain or stress) bridge at critical point, may fail upon occurrence following cases (Y.K. Lin, 1967): i. reaches, for first time, either an upper level A lower –B, where and B large positive numbers (Fig. 1(a)). ii. Damage structure accumulated as fluctuates small moderate excursion not enough cause failure type, occurs when damage reaches fixed total. iii. Failure occur if spends too much its time off range, i.e., it is. outside set limits more than minimum fraction lifetime 1(b)) case, called passage (also failure), objective this chapter. According definition, means determining probability that prescribed threshold (displacement, stress other level) will be exceeded, during period time. does lead catastrophic bridge, but in view serviceability consideration important. Therefore, designing structures against reduce such failure, over expected acceptable level. most vibration problems, there close unity any given high exceeded excited long Seismic due ground motion obtained chapter frequency domain spectral analysis. assumed partially correlated stationary process. analysis, quasi-static deck produced support dully considered. possibility future earthquake then presented various levels (taken yield parametric performed show effect some important parameters level, soil conditions, degree correlation, angle incidence etc. on failure.