连续梁倒拆施工倾覆稳定性的体系可靠度方法

针对连续梁双悬臂挂篮逆施工顺序拆除施工的纵向倾覆稳定性,采用可靠度方法对其进行安全评价.提出因果链模式的体系可靠度方法,推导拓展了全概率公式的应用范围,并据此推导了因果链模式体系可靠度计算公式,计算结果和串并联联接模式很好吻合.推导拓展了贝叶斯公式的应用范围,分析得出导致体系失效最主要的失效模式.对最主要的失效模式进行了参数敏感性分析,得出可以指导拆除施工抗倾覆问题的结论,即吊索强度、根数和钢管桩强度以及切割不对称误差对拆除体系倾覆安全可靠度影响非常大.

System Reliability Method to Analyze Overturning Stability of Demolition Construction of Continuous Beam Bridges

The overturning stability of cantilever beam bridges in demolition process was assessed by the method of reliability. Causality-chains method of system reliability was proposed. The application of total probability formula was developed. And the system reliability formula of causality-chains was derived with the developed total probability formula. The calculated results by the formula are well anastomosed with the series parallel connection. Furthermore, the application of Bayes formula was developed and the most important failure mode was analyzed by it. The parameters sensitivity of the most important failure mode was analyzed, and the conclusions to guide the demolition deconstruction about overturning stability were obtained: lifting rope strength, rope number and temporary supports strength are important to overturning stability of the demolition system.