中贵管道乌江悬索跨越主缆的施工控制
Control on construction of the main cable for Wujiang suspension crossing of Zhongwei-Guiyang Pipeline
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摘要: 乌江管道悬索跨越主缆重力刚度偏小、柔性较大, 主缆架设线形受散索套定位、索鞍预偏量、环境温度和跨度的影响较大, 调索困难。为了精确调整索股线形, 基于无应力状态理论, 建立了索股无应力长度和线形精确迭代求解算法, 综合考虑温度、跨度等因素, 快速有效地控制索股到空缆的高程。采用参数变化法, 分析温度和跨度对索股线形和锚跨张力的影响, 用于索股调整完毕后的稳定性观测及其线形随温度、跨度变化的规律性校验。施工观测结果表明: 该工程上下游索股的相对或绝对高程偏差均满足施工技术规范要求。该迭代算法在乌江管道悬索跨主缆施工中适应性好, 计算速度快, 监控工作效率高, 是管道悬索跨越主缆索股架设和调整的一种有效方法。Abstract: The main cable for suspension crossing of Wujiang Pipeline is characterized by low gravity stiffness and high flexibility. It is hard to be adjusted since its shape is greatly influenced by the positioning of anchorage cable sleeve, prebias of cable saddle, ambient temperature and span. In order to precisely adjust the suspended cable shape, based on the unstressed state theory, this paper establishes the precise iterative algorithm for non-stress length and shape of cable strand, which comprehensively considers the factors like temperature and span and can control and adjust the elevation between cable strand and free cables quickly and effectively. Parameter variation method is adopted to analyze the possible impacts of temperature and span on the suspended cable shape and cable tension, so as to observe the stability after the adjustment of cable strand and verify the changes of cable shape with temperature and span. The construction observation result shows that both relative and absolute elevation deviations of the cable strand in upstream and downstream of this project meet the requirements of technical specification. This iterative algorithm adapts well in the construction of main cable for suspension crossing of Wujiang Pipeline. With advantages of fast calculation and high monitoring efficiency, this algorithm is an effective and reliable analysis method for building and adjusting cable strand for suspension crossing of pipelines.