公路桥梁承载能力评估目标可靠指标计算

Calculation of Targeting Reliability Index for Bearing Capacity Evaluation of Highway Bridges in China

为校准我国现行桥梁设计规范中隐含的可靠指标,给出桥梁承载能力评估目标可靠指标,在收集我国3个路段2年连续车辆流数据(约3 000万辆卡车)的基础上,选取我国《公路桥涵设计通用规范》(JDG D60-2004)为校准规范,利用结构可靠性理论校准该规范在目前车辆流数据下的隐含可靠指标;提出我国已建桥梁承载能力评估目标可靠指标计算方法及确定原则。计算结果表明:在目前收集车辆流数据下,我国现行桥梁设计规范隐含可靠指标为4.063,建议我国已建公路桥梁承载能力评估目标可靠指标为3.563。

In order to calibrate the inherent reliability index in the present bridge design code in China and provide the target reliability index for the evaluation of bridge bearing capacity, the structural reliability theory was used to adjust the inherent reliability index under the current traffic volume and to propose a calculation method and identifying principles for the target relia- bility index used for bearing capacity evaluation of existing bridges in China. The study was done based on the collection of the traffic volume of three highways two years running （about 30 mil- lion trucks） and by taking the General Code for Design of Highway Bridges and Culverts as the adjustment code. The results of the calculation indicate that under the current traffic volume col- lected, the inherent reliability index in the present bridge design codes in China is 4. 063, it is suggested that the target reliability index for the bearing capacity evaluation of existing highway bridges in China take the value of 3. 563.