摘要
Abstract
In response to the problems of linear deviation control and stress state stability faced by large-span and large section cast-in-place prestressed concrete continuous rigid frame bridges during cantilever construction,based on Hengmen West Waterway Bridge on Zhongshan-Kaiping Expressway,this paper focuses on the prominent technical bottlenecks of linear control difficulty,uncontrollable stress response,and frequent construction process disturbances of single chamber large section cantilever cast-in-place box girders under complex construction conditions.Key processes and monitoring technologies such as optimization of hanging basket combination support system,graded preloading and dynamic compensation,full process linear monitoring,and multi-source stress monitoring integration have been systematically studied and practiced.By constructing an elastic-plastic deformation compensation model and establishing a three-dimensional response relationship of temperature stress time history,the goals of achieving a height difference of≤10 mm for the box girder closure section,a linear deviation of≤8 mm for the bridge deck,a prestress loss control of≤10%,and precise and controllable stress temperature coupling can be achieved.关键词
悬臂现浇/大断面箱梁/线性控制/应力监测/预应力防护/高精度施工Key words
cantilever cast-in-place/large section box girder/linear control/stress monitoring/prestress protection/high precision construction分类
交通工程
