钢-混凝土连续组合梁桥负弯矩区抗裂设计

Anti-cracking design for hogging moment regions of steel-concrete continuous composite beam bridges

为进一步验证抗拔不抗剪连接件对组合梁桥负弯矩区抗裂的效果,并研究采用该连接件时负弯矩截面的设计方法,利用考虑滑移效应的组合梁负弯矩区受力模型,推导了采用抗拔不抗剪连接时组合梁负弯矩截面承载力的计算模型,计算结果与有限元分析结果吻合良好。通过理论推导,进一步证明了抗拔不抗剪连接件对负弯矩截面承载力的折减不大,且能有效延缓桥面板开裂。基于所推导的公式,总结了钢-混凝土连续组合梁桥负弯矩截面的简化设计流程,以供工程设计实践参考。

In order to verify the effects of uplift-restricted and slip-permitted(URSP)connection on anti-cracking of hogging moment regions and develop the design methods,the calculation model of bearing capacity in hogging moment section of composite beams with URSP connections was built up by using the stress model of composite beams with hogging moment region considering slip effect.The model was verified in good agreement with the finite element analysis results.It could be further verified that the reduction of bearing capacity in the hogging moment section is small,and the cracking of the bridge deck is effectively controlled.Based on the formula deduced in this paper,the simplified designing procedure of the hogging moment section using URSP connections was summarized for engineering reference.