基于可靠性分析的大跨度跨越管桥寿命预测

Service Life Prediction for Longspan Overhead Crossing Pipe Bridge Based on ReliabilityAnalysis

根据管桥结构自身的受力特点,采用复合蒙特卡罗抽样法,结合有限元及二次开发工具APDL,对跨越管道的灵敏度和可靠性指标参数进行了分析和计算。以腐蚀速率分析模型为基础,分析了随机参数共同作用下结构的年失效概率。以某现役管桥为例,对其可靠性进行了全面分析。计算结果表明,与结构可靠性指标关系较密切的参数是主索截面积、管道外径和介质油密度。采用不同风险地段允许的失效概率对管桥的使用寿命进行了预测,低风险地段管桥的安全寿命可达39年,高风险地段管桥的安全寿命为26年。

Based on stressed characteristics of pipe bridge structure itself,adopting complex Monte-Carlo sampling method andcombined with finite element as well as a secondary development tool APDL. index parameters in sensitivity and failure probabilityof overhead crossing pipeline are analyzed and calculated. On the basis of analysis model for corrosion rate, yearly failure rate ofstructure at coaction of random parameters is analyzed. Taking some in-service pipe bridge as an example, its refiability isentirely analyzed. Calculation results show that the parameters closer to reliability index are main cable cross area, external pipediameter and density of oil medium. Service life of the pipe bridge is forecasted based on allowable failure probabilities atdifferent risk areas. Safe life of a pipe bridge at low risk area is up to 39 years, safe life of a pipe bridge at high risk area is upto 26 years.