Multi-level reliability-based load-carrying capacity evaluation method of bridges
To introduce the philosophy of"conservative design,non-conservative evaluation"into Chinese bridge evaluation code,an"inventory and operation"two target-reliability level bridge evaluation method is proposed.The similarities and differences between Chinese and American bridge evaluation codes are summa-rized,which include the unity check formulas,target reliability indexes and load factors.Based on the com-parison results,the method of adjusting the target reliability indexes by reducing the live load factor is intro-duced into Chinese code.First,the evaluation reliability index of operational bridges is obtained through reduc-ing the design reliability of inventory bridges by 0.5.Then,the evaluation live load factors of operational bridges with different load types and live load conditions are calibrated through first order second moment(FOSM)method,and an"inventory bridges 1.4,operational bridges 1.2"live load factors selection sugges-tion is given.Finally,the feasibility of the proposed method is verified through a simply supported RC T-beam bridge evaluation example.The results show that the most unfavorable demand-capacity ratio is reduced by 0.07 compared with the specification method,which realizes the non-conservative evaluation philosophy of the operational bridge.
万方数据
维普
