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PBL剪力连接件是组合梁桥中波纹钢腹板和混凝土上下翼缘板连接的关键构造,研究PBL剪力连接件的粘结滑移性能是连接件设计的关键环节。该文简要介绍了PBL剪力连接件的发展和研究现状,结合波形钢腹板PC组合箱梁桥工程背景,进行了4个PBL连接件的静载推出试验,分析了腹板厚度和孔径大小对连接件粘结滑移性能、极限承载能力和破坏机制的影响。实验结果表明,各个试件有相似的滑移趋势并表现出一定的延性,随着腹板厚度和连接件孔径的增大,极限承载能力增强。同时,通过对荷载和水平位移关系的分析,得到连接件的受力机理为:在受力初期,混凝土受到剪力件的力传递发生变形向外膨胀;随着荷载的增大,剪力件发生明显滑移,混凝土发生向外侧的位移。剪力连接件腹板、翼缘和钢腹板上的应变发展趋势符合加载受力的传递机理。最后,对比和分析了连接件极限承载力的理论结果和试验结果,阐述了影响极限承载力的主要因素,并且在考虑安全实用意义的基础上,提出了一个新的估算公式,可以较好地估算本次试验结果。
PBL shear connectors are the key structures in the connection of corrugated steel webs and concrete upper and lower flange plates in composite girder bridges. Studying the bond-slip properties of PBL shear connectors is a key link in the design of connectors. In this paper, the development and research status of PBL shear connectors are briefly introduced. Based on the engineering background of corrugated steel web PC composite box girder bridge, four PBL connectors are tested under static load. The effects of web thickness and pore size Impact on bond slipping performance, ultimate bearing capacity and failure mechanism of connectors. The experimental results show that all the specimens have similar slip tendency and exhibit some ductility. With the increase of the web thickness and the diameter of the connector, the ultimate bearing capacity is enhanced. At the same time, through the analysis of the relationship between load and horizontal displacement, the stress mechanism of the connector is obtained as follows: At the initial stage of the stress, the concrete will be deformed and outwardly expanded by the force transfer of the shear component; as the load increases, Significant slip occurred, concrete displacement occurred to the outside. The development trend of the strain on the webs, flanges and steel webs of the shear connectors accords with the transmission mechanism under load. Finally, the theoretical and experimental results on the ultimate bearing capacity of the connector are compared and analyzed. The main factors affecting the ultimate bearing capacity are expounded. Based on the practical significance of safety, a new estimation formula is proposed, which can better Estimate the test results.