A method of cable safety analysis is proposed for safety evaluation of long-span cable-stayed bridges. The Daniels' effect and the probability of broken wires in the cable are introduced to develop the cable strength...A method of cable safety analysis is proposed for safety evaluation of long-span cable-stayed bridges. The Daniels' effect and the probability of broken wires in the cable are introduced to develop the cable strength model and the reliability assessment technique for long-span cable-stayed bridges based on the safety factors analysis of stay cables in service. As an application of the proposed model, the cable safety reliability of the cable No. 25 of Zhaobaoshan cable-stayed bridge in China is calculated. The effects of various parameters on the estimated cable safety reliability are investigated. The results indicate that the proposed method can be used to assess the safety level of stay cables in cable-stayed bridges effectively. The Daniels' effect should be taken into account for assessment, and the probability of broken wires can be used to simulate the deterioration of stay cables in service.展开更多
文摘为探究爬模施工进程中索塔空间温度场和应力场分布,掌握塔柱线形特性,提出一种索塔爬模施工仿真分析方法.利用Fortran编程语言开发相应子程序,对结构施加复杂温度边界,实现不同节段混凝土水化放热、收缩徐变.利用Abaqus软件对索塔爬模施工过程进行分析.结果表明:施工过程中索塔空间温度分布不均匀,塔柱表里最大温差达25.9℃,向阳面与背阴面温差最大为9℃;考虑温度效应后,塔柱所受拉应力更大,且空间应力分布具有很强的时变性,索塔线形特征与变化规律也发生改变;施工塔顶累积竖向位移先增大后减小,在爬模第16节段达到最大值20.5 mm;施工过程塔顶累计顺桥向和横桥向位移更大,最大值分别为6.5和22.3 mm.
基金The Opening Fund of the Key Laboratory of UrbanSecurity and Disaster Engineering of Ministry of Education (NoEESR200701)the Opening Fund of Beijing Laboratory of EarthquakeEngineering and Structural Retrofit
文摘A method of cable safety analysis is proposed for safety evaluation of long-span cable-stayed bridges. The Daniels' effect and the probability of broken wires in the cable are introduced to develop the cable strength model and the reliability assessment technique for long-span cable-stayed bridges based on the safety factors analysis of stay cables in service. As an application of the proposed model, the cable safety reliability of the cable No. 25 of Zhaobaoshan cable-stayed bridge in China is calculated. The effects of various parameters on the estimated cable safety reliability are investigated. The results indicate that the proposed method can be used to assess the safety level of stay cables in cable-stayed bridges effectively. The Daniels' effect should be taken into account for assessment, and the probability of broken wires can be used to simulate the deterioration of stay cables in service.