先张法折线预应力钢束放张工序优化分析  

Optimization Analysis of Prestressed Tendons’ Tensing Order of Pre-tensioned Girder

作　　者：郭增伟 朱华 谢新龙 刘兵 GUO Zengwei;ZHU Hua;XIE Xinlong;LIU Bing(School of Civil Engineering,Chongqing Jiaotong University,Chongqing,China,400074;Highway Investment Group of Jiangxi Co.Ltd.,Nanchang,China,330025;Traffic Construction Engineering Quality Supervision Administration of Jiangxi,Nanchang,China,330025)

机构地区：[1]重庆交通大学土木工程学院,重庆400074 [2]江西省高速公路投资集团有限责任公司,江西南昌330025 [3]江西交通建设工程质量监督管理局,江西南昌330025

出　　处：《沈阳建筑大学学报（自然科学版）》2019年第6期1019-1026,共8页Journal of Shenyang Jianzhu University：Natural Science

基　　金：国家自然科学基金项目(51878106,51478072);重庆市基础与前沿研究计划项目(cstc2015jcyjBX0022);桥梁工程结构动力学国家重点实验室开放基金项目(201501)

摘　　要：目的精细化分析折线先张法混凝土T梁分批次放张过程中混凝土梁体应力变化,缓解折线先张法混凝土T梁预应力钢束弯折位置的应力集中现象.方法基于ANSYS中SOLID65钢筋混凝土整体式模型,建立折线预应力混凝土T梁的非线性有限元实体分析模型,分析和探讨分次放张预应力钢束过程中折线钢束弯折点附近混凝土主压应力、主拉应力、应力集中系数的变化.结果相比一次放张而言,钢束分批次放张后预应力筋弯折点处混凝土主压应力波峰数量和应力极值均有明显减小,但主拉应力波峰数量和应力极值却有明显增大;钢束分批放张时折线钢束弯折点位置处的最大拉应力、平均应力随着放张的预应力钢束的增多而逐渐增大,应力集中系数前期变化较大,后期逐渐减小趋于平稳.结论先将所有直线筋张拉然后再张拉折线筋对于减小弯折点附近最大拉应力和应力集中系数有显著作用,能够明显缓解弯折位置的应力集中现象.In order to figure out the stress changing of pre-tensioned concrete T-beam in the process of releasing tendons in batches,and alleviate the stress concentration phenomenon near the break point of prestressing tendons,this paper proposed the nonlinear finite element model of the prestressed concrete T-beam based on SOLID65 reinforced concrete integral model in ANSYS to analyze the principal compressive stress,the principal tensile stress,and the stress concentration factor near the break point of prestressing tendons during the process of releasing tendons.Analysis results shows that comparing to releasing tendons all at once,releasing tendons in batches causes the peak number and the peak value of principal compressive stress near the break point of the prestressing tendons decreased largely and the principal tensile stress increased largely.The maximum principal tensile stress and mean stress rise with the increase of the number of released prestressing tendons.At prophase,the stress concentration factor changes greatly and gradually decreases and stabilizes at later stage.Releasing all straight prestressing tendons first then releasing polyline prestressing tendons has a significant effect on reducing the maximum value of principal tensile stress and stress concentration factor,which can significantly alleviate the stress concentration phenomenon near the break point of prestressing tendons.

关 键 词：桥梁工程 T梁 折线配筋 分次放张 应力集中 

分 类 号：U441.3[建筑科学—桥梁与隧道工程]