焊接锚垫板锚固区传力性能试验与拉压杆模型分析  

Experimental Study on Load Transfer Performance of Welded Anchor Plates in Anchorage Zone and Analysis of Strut-and-Tie Model

作　　者：王赞芝[1] 杨春旭 钟洋 李先一 江倩敏 WANG Zanzhi;YANG Chunxu;ZHONG Yang;LI Xianyi;JIANG Qianmin(School of Civil Engineering and Architecture,Guangxi University of Science and Technology,Liuzhou 545006,China;Survey,Design and Research Institute of China Railway Tunnel Group Co.,Ltd.,Guangzhou 511458,China;Zhejiang Huazhan Institute of Engineering Research and Design Co.,Ltd.,Ningbo 315012,China)

机构地区：[1]广西科技大学土木建筑工程学院,广西柳州545006 [2]中铁隧道局集团有限公司勘察设计研究院,广州511458 [3]浙江华展工程研究设计院有限公司,宁波315012

出　　处：《铁道标准设计》2024年第12期75-83,共9页Railway Standard Design

基　　金：广西科技计划项目(桂科AB17292022)。

摘　　要：铸造锚垫板作为铁路桥梁后张预应力锚固体系中重要传力构件,存在易发生脆性破坏、生产过程能耗高、质量参差不齐等问题。为进一步提高锚固体系结构性能,避免铸造锚垫板的缺陷,设计了一种新型环保焊接锚垫板。按照有关国家标准的要求,制作了11个应用该新型锚垫板的钢筋混凝土试件,开展锚固区传力性能试验,通过试件的破坏过程、破坏形态和极限承载力等方面探究新型锚垫板的力学性能。其次,构建反映混凝土锚固区力流传递的拉压杆模型,并依据新型锚垫板锚固区有限元分析及力流线分析对拉压杆模型的构形进行优化。最后,利用拉压杆模型推导出锚固区极限承载力公式。结果表明:在循环荷载作用下,新型锚垫板试件的传力性能试验结果满足规范要求,极限承载力的试验值比规范理论计算值高4%~18%,且试件破坏时新型锚垫板仅产生局部翘曲,未发生脆性破坏;随着新型锚垫板锚固区压应力扩散角的减小,锚固区承载力增大,且压应力扩散角均值为39.7°;新型锚垫板锚固区极限承载力公式计算结果与试验结果基本吻合,平均误差为2.73%,为焊接锚垫板极限承载力计算提供了一种新方法。Cast anchor plates,as key load-transfer components in the post-tensioning anchorage system of railway bridges,have issues such as susceptibility to brittle failure,high energy consumption during production,and inconsistent quality.To improve the structural performance of the anchorage system and address the defects associated with cast anchor plates,a new type of environmentally friendly welded anchor plate was designed.According to the requirements of relevant national standards,11 reinforced concrete specimens using new bearing plates were fabricated,and load transfer performance tests in the anchorage zone were conducted.The mechanical properties of the new anchor plate were explored considering the failure process,failure modes,and ultimate bearing capacity of the specimens.Furthermore,a strut-and-tie model reflecting the force transfer within the concrete anchorage zone was constructed.Based on finite element analysis and force flow analysis of the anchorage zone for the welded anchor plate,the configuration of the strut-and-tie model was optimized.Finally,the ultimate bearing capacity formula for the anchorage zone was derived through the strut-and-tie model.The results showed that under cyclic loading,the load transfer performance of the welded anchor plate specimens met the code requirements.The experimental ultimate bearing capacity exceeded the theoretical value calculated by the code by 4%to 18%,and the specimens only exhibited local warping without brittle failure.As the compressive stress diffusion angle in the anchorage zone decreased,the bearing capacity of the anchoring zone increased,with an average of diffusion angle of 39.7°.The calculated ultimate bearing capacity formula for the welded anchor plate anchorage zone was found to be in good agreement with the experimental results,with an average error of 2.73%,providing a new approach to calculating the ultimate bearing capacity of the welded anchor plates.

关 键 词：铁路桥梁 焊接锚垫板 传力性能试验 拉压杆模型 应力扩散角 极限承载力 锚固区 

分 类 号：U24[交通运输工程—道路与铁道工程] U448.35[建筑科学—桥梁与隧道工程]