基于影响矩阵的桁架结构预应力损失识别方法  

Prestress Loss Identification Method Based on Influence Matrix in Truss Structure

作　　者：刘艳辉[1] 张阳阳 刘军校 任鹏 卓彪 LIU Yanhui;ZHANG Yangyang;LIU Junxiao;REN Peng;ZHUO Biao(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;China CREC Railway Electrification Bureau Group Beijing Construction Company,Beijing 100039,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]中铁电气化局集团北京建筑工程有限公司,北京100039

出　　处：《西南交通大学学报》2019年第5期1030-1037,共8页Journal of Southwest Jiaotong University

基　　金：国家重点研究课题(2016YFC0802205-9);国家自然科学基金资助项目(51378427)

摘　　要：为计算出每束预应力钢束实时的预应力损失,依据预应力桁架结构观测变形,基于位移影响矩阵原理提出一种预应力损失识别方法.通过有限元分析,建立预应力损失值与桁架结构观测点位移值之间的关系方程,并依据极小值优化原理,获得预应力损失值.研究表明:当单位预应力损失取30%~50%时,得到的位移影响矩阵计算预应力损失时误差最小,约为1%~2%;三角形桁架1/4跨度和3/4跨度处位移观测点对预应力损失的敏感性最高.最后,以黔渝线上某高铁站房的大跨钢筋预应力桁架结构为例,验证了该方法的正确性.In order to calculate the real-time prestress loss of prestressed strands according to the observed deformation of prestressed truss structure,a prestress loss identification method based on displacement influence matrix is proposed.By finite element analysis,the relationship between the prestress loss and displacement of the observation point on the truss structure is formulated.Moreover,according to the minimum principle,the prestress loss is obtained.The results show that when the unit prestress loss ranges between 30%and 50%,there is minimum error around 1%–2%in calculating prestress loss with displacement influence matrix;the displacement observation point is most sensitive to prestress loss,when it is located at the 1/4 span and 3/4 span of the truss.Finally,by taking an example of the long-span prestressed truss structure near a high-speed railway station on the Qian-Yu line,the accuracy of the method is verified.

关 键 词：桁架结构 结构变形 位移影响矩阵 预应力损失计算 

分 类 号：TU378.6[建筑科学—结构工程]