【摘要】 针对斜拉桥失效路径繁多的问题,采用改进的β约界法限制分枝规模,寻找并识别对结构体系可靠度起主导作用的主要失效模式。通过现场试验建立了高强度混凝土早龄期力学性能的经时概率模型。同时,考虑各主要失效模式间的相关性,提出了计算体系失效概率上下界的实用方法。通过一座双塔斜拉桥施工期体系可靠度的计算实例表明了这一方法的有效性。研究成果对于评价混凝土斜拉桥施工期的结构整体性能和安全程度具有参考价值。更多还原

【Abstract】 Based on the problem that cable-stayed bridge has many failure paths,modified β-unzipping method was suggested to seek and identify major failure patterns to structural system reliability.On the basis of spot sample and laboratory experiment,authors studied the time-variant probability model early age period mechanical properties of high-strength concrete.Considered the effect of correlation among main failure modes,a practical approach for calculating upper and lower boundary of system failure probability was proposed. A cable-stayed bridge consisting two pylons was selected to show the efficiency and accuracy of the proposed algorithm.The method can effectively evaluate whole structural performance and safety degree of concrete cable-stayed bridge.更多还原