大跨度混合梁斜拉桥耐久性失效风险评估

Risk Assessment of Durability Failure for Large-span Hybrid Girder Cable-stayed Bridge

为建立大跨度混合梁斜拉桥的耐久性失效风险评估体系,在分析耐久性和风险已有定义的基础上,从评估角度明确了耐久性失效风险的相关概念.考虑耐久性时间跨度大的特点,通过调研咨询识别了长期作用类型的风险因素,建立了大跨度混合梁斜拉桥耐久性失效风险源库.综合专家调查法、模糊综合评判法和层次分析法,研究了基于专家调查的模糊层次分析法用以评估耐久性失效风险.将重要度分析该概念引入耐久性失效风险评估,提出了耐久性失效风险重要度分析,该方法可以评价底层风险源对顶上风险事件的影响程度.以某长江大桥算例实践了上述风险评估体系,证明了其可行性.该体系可为大跨度混合梁斜拉桥的安全运营和预防性养护提供参考.

To construct a risk assessment system of durability failure for large span hybrid girder cable-stayed bridge,new definitions related to durability failure risk were proposed from an assessment view based on the analysis of existing concepts of durability and risk.Considering the long time span of durability,risk factors which have long-term effect were identified through investigation and consultation,thus the durability failure risk factor database of large span hybrid girder cable-stayed bridge was built. Combining expert investigation method,fuzzy comprehensive evaluation method and analytic hierarchy process,the fussy analytic hierarchy process based on professor research was studied to assess the risk of durability failure.Introducing the analysis of importance rate to risk assessment of durability failure,durability failure risk importance analysis was proposed which can assess the impact on top risk event of bottom risk factors.Based on a certain Changjiang Bridge,the foregoing risk assessment system was practiced and the feasibility was proved,providing reference to security operation and preventive maintenance for large-span hybrid girder.