大跨度U形渡槽预应力钢绞线张拉顺序数值模拟及方案比选  

Numerical Simulation and Scheme Comparison of Tension Sequence of Pre-stressed Steel Strand in Large-Span U-shaped Aqueduct

作　　者：汪安南 雷艳[1] 黎康平 李同春[2] WANG Annan;LEI Yan;LI Kangping;LI Tongchun(PowerChina Northwest Engineering Corporation Limited,Xi'an 710065,China;College of Water Resources and Hydropower Engineering,Hohai University,Nanjing 210024,China)

机构地区：[1]中国电建集团西北勘测设计研究院有限公司,西安710065 [2]河海大学水利水电学院,南京210024

出　　处：《西北水电》2024年第3期67-73,共7页Northwest Hydropower

基　　金：国家重点研发计划(2022YFC3005403);中国电力建设股份有限公司科技项目(DJ-ZDXM-2021-10)。

摘　　要：为探究大跨度U形渡槽预应力钢绞线张拉过程中拆模时机对渡槽槽身结构受力状态的影响,以国内某大跨度U形预槽为例,考虑温度荷载,基于单弹簧联结单元法模拟预应力钢绞线与混凝土的相互作用,通过数值模拟方法研究预应力钢绞线张拉过程中的拆模时机对渡槽槽身结构应力响应的影响,进而基于渡槽槽身的应力控制标准及预应力钢绞线张拉过程对渡槽预制台座的占用时间,提出了最优的预应力钢绞线张拉方案。结果表明:拆模前施加部分纵向、环向预应力不仅能满足张拉过程中槽身内壁面不出现拉应力的要求,同时能减少对渡槽预制台座的占用时间。To study the influence of demolding time on the stress state of the body structure of the large-span U-shaped aqueduct during the tensioning process,the tensioning scheme of the pre-stressed steel strand is compared and selected.Taking a large-span U-shaped pre-stressed aqueduct in China as an example,the interaction between pre-stressed steel strand and concrete is simulated using the single spring connection element method considering temperature load,and the influence of demolding time on the stress response of aqueduct body during the tensioning process of pre-stressed steel strand is studied by numerical simulation.Then based on the stress control standard of aqueduct body and the occupation time of prefabricated pedestal of aqueduct during the tensioning process of pre-stressed steel strand,the optimum tensioning scheme of pre-stressed steel strand is proposed.The results show that the application of partial longitudinal and circumferential prestress before demolding can not only meet the requirement of no tensile stress on the inner wall of the aqueduct during the tensioning process,but also reduce the occupying time of the aqueduct prefabrication pedestal.

关 键 词：大跨度U形渡槽 拆模时机 预应力 张拉方案 数值模拟 

分 类 号：TV672.3[水利工程—水利水电工程]