接缝处纵向钢筋连续预制混凝土节段梁试验研究

Experimental Study of Precast Segmental Beams with Steel Rebars Through Joints

摘要:

预制混凝土节段梁桥在城市基础设施建设中具有十分重要的地位。针对传统设计中接缝处钢筋断开的问题，提出了接缝处纵向钢筋连续设计方案。研究的主要目的是提升节段梁的抗裂性能以及结构耐久性。通过简支节段梁的荷载试验并结合数值分析，对比了新型接缝与传统接缝在开裂荷载、极限承载能力、变形特性和破坏模式方面的差异。研究结果表明：接缝处纵向钢筋连续布置对节段梁的抗裂性能有明显提高。提出的二维有限元模型可有效模拟接缝处纵向钢筋连续节段梁以及传统节段梁的全过程受力行为，提出的极限承载能力公式可较准确预测节段梁的受力性能。相关研究表明，接缝处纵向钢筋连续接缝设计为提高预制混凝土节段梁的工程应用性能提供了新思路。

Abstract:

Precast concrete segmental girder bridges play a vital role in urban infrastructure construction. To address the problem of reinforcement discontinuity at joints in conventional designs， this study proposes a new joint scheme with steel rebars through joints， ensuring continuity of longitudinal reinforcement. The primary objective is to improve the cracking resistance and long-term durability of segmental girders. A series of load tests on simply supported segmental beams， combined with numerical analysis， were conducted to compare the performance of the proposed joint with that of conventional joints. Key parameters such as cracking load， ultimate load capacity， deformation behavior， and failure modes were systematically evaluated. The results demonstrate that incorporating steel rebars through joints significantly enhances the cracking resistance of segmental beams. The proposed two-dimensional finite element model effectively simulates the entire loading process of segmental girders with both continuous and conventional joints. In addition， a simplified formula for predicting ultimate load capacity is developed， offering improved accuracy in structural performance evaluation. These findings suggest that the use of steel rebars through joints provides a promising design approach to improve the engineering performance and practical applicability of precast concrete segmental girders.