焊钉集群式后结合超高性能混凝土组合桥面板抗弯性能

Flexural Performance of Post-Combined Ultra-High Performance Concrete Composite Bridge Deck with Grouped-Stud Arrangement

摘要:

为考察焊钉集群布置对后结合超高性能混凝土（UHPC）组合桥面板受力性能的影响，进行常规均匀焊钉布置组合桥面板及群钉布置后结合组合桥面板试件的弯曲荷载试验和基于材料塑性损伤模型的有限元参数化分析。试验结果表明，群钉布置与均匀焊钉布置试件破坏模式特征均为UHPC板压溃、钢结构U肋底面屈服，二者弹性抗弯刚度分别为232 kN·mm^-1及213 kN·mm^-1，承载力分别为2 154 kN及2 049 kN。U肋屈服前，两试件的界面最大滑移值均小于0.2 mm。两试件应变分布及发展规律相似，截面应变分布均近似服从平截面假定。参数化分析结果表明，群钉孔纵向布置间距由600 mm增至1 200 mm，承载力及弹性刚度无明显变化。群钉孔尺寸相同时，孔间距对UHPC黏结界面结合状态无显著影响。间距600 mm相较1 200 mm布置可更好地保证焊钉受力安全性及截面组合效应。综合对比参数化模型抗弯性能，纵向间距600 mm结合群钉孔内2×3群钉布置对正弯矩作用下后结合钢-UHPC组合桥面板受力状态改善更为有利。

关键词:钢-UHPC组合桥面板;群钉连接件;受弯试验;有限元模拟;参数化分析

Abstract:

To investigate the effects of grouped-stud arrangement on the mechanical performance of the post-combined UHPC （ultra-high performance concrete） composite deck， bending load tests and finite element parametric analysis based on the UHPC plastic damage model were conducted for a composite deck specimen with averagely spaced studs and a post-combined composite deck specimen with grouped-stud connection. The test results show that the failure characteristics of these two specimens are UHPC plate crushing and steel U-rib bottom yielding. The elastic flexural stiffness of the specimen with grouped-stud connection and the one with averagely spaced studs are 232 kN·mm^-1 and 213 kN·mm^-1 respectively， and the bearing capacity are 2 154 kN and 2 049 kN respectively. The maximum interface slip value of these two specimens is less than 0.2 mm before the U-rib yielding. These two specimens have the same strain distribution and strain development pattern. The cross-sectional strain distributions of the specimens approximately obey the plane section assumption. The parametric analysis results show that there is no significant change in the bearing capacity and elastic bending stiffness when the grouped-stud hole spacing is increased from 600 mm to 1 200 mm. When the grouped-stud hole size is the same， the hole spacing has no significant effect on the bonding state of UHPC bonding interfaces. The 600 mm spacing of grouped-stud holes can better ensure the safety of studs and the cross-sectional combination effect than the 1 200 mm arrangement. Comparing the flexural performance of parametric models， the longitudinal spacing of 600 mm combined with the 2×3 grouped-stud arrangement in the hole is more favorable to improve the stress state of the post-combined steel-UHPC composite deck under positive bending.

Key words:steel-UHPC (ultra-high performance concrete) composite deck;grouped-stud connector;flexural test;finite element simulation;parametric analysis