预制NC墩柱灌浆波纹管+UHPC榫组合连接的弯压性能有限元分析

Finite Element Analysis of Bending and Compression Performance of Prefabricated NC Column Grouting Bellows+UHPC Mortise Joint

在预制桥墩连接节点处采用UHPC可以延缓试件的开裂,提高塑性铰的转动能力。提出了一种用于预制混凝土柱的灌浆波纹管+现浇UHPC榫组合连接方式,能解决目前依靠传统的单一灌浆波纹管连接构件所存在的一些问题,并通过有限元分析软件ABAQUS分析不同接缝组合的受力特点,与试验结果进行比较和验证。结果表明:传统的灌浆波纹管连接柱接缝处容易出现开口,钢筋应力集中在接缝附近处,承载能力和延性均很差。灌浆波纹管+UHPC榫连接柱,得益于UHPC超高力学性能,改善了钢筋在接缝处的应力集中,提高了试件的承载能力和延性,且通过在灌浆波纹管+UHPC榫连接柱内部植筋,改善了界面粘接性能,加强了整体抗弯强度,得到承载能力要大于完整现浇柱,但延性会略微降低。

Using UHPC in the joint of prefabricated pier can delay the cracking of the specimen and improve the rotation capacity of plastic hinge.In this paper,a new joint method of grouted bellows and cast-in-place UHPC tenon for precast concrete columns is proposed,which can solve some problems existing in the traditional single grouted bellows joint components.The stress characteristics of different joint combinations are analyzed by the finite element analysis software ABAQUS,which is verified by the test results.The results show that the opening is easy to appear at the joint of the grouting bellows connection column,the stress of the reinforcement is concentrated near the joint,and the bearing capacity and ductility are very poor.Because of UHPC super-high mechanical properties,the stress concentration of steel bars at joints is improved,and the bearing capacity and ductility of specimens are improved.In this paper,by planting steel bars in the joint,the interface bonding performance is improved and the overall bending strength is strengthened.The bearing capacity is greater than that of the complete cast-in-place column,but the ductility is slightly reduced.