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为研究港珠澳大桥沉管隧道节段接头剪力键破坏状态与机理,采用ANSYS软件对沉管节段在纵、横向地基不均匀沉降与不均匀回淤荷载作用下的弯曲与扭转工况进行三维数值模拟。同时,以长安大学路基沉降试验平台为基础,对沉管隧道的3个节段进行了缩尺比为1∶4.69的大比尺沉管节段模型试验。对比数值模拟与试验得到的剪力键剪力结果得出,弯曲与扭转工况中竖向剪力键起主要作用,弯曲工况中剪力键受力状态为弯剪,扭转工况中剪力键存在“剪滞效应”。通过对竖向剪力键应力矢量的分析,并结合剪力键的破坏特征与破坏过程,提出剪力键的破坏机理。最后,对剪力键的设计提出了相应优化建议。
In order to study the damage state and mechanism of shear bond of immersed tunnel segment joints of Hong Kong-Zhuhai-Macao Bridge, ANSYS software was used to analyze the flexural and torsional behavior of immersed segments under uneven settlement of uneven vertical and horizontal foundations and nonuniform back- Three-dimensional numerical simulation. At the same time, on the basis of the foundation settlement test platform of Chang'an University, the three sections of immersed tunnel were subjected to the model test of large scale immersed tube segment with the scale ratio of 1: 4.69. Comparing with the numerical simulation and experimental results, it is concluded that the vertical shear force plays a major role in the bending and twisting conditions. In the bending condition, the shear force is in the form of bending shear and the torsion shear Force key exists “shear lag effect”. Through the analysis of vertical shear stress vector and the failure characteristics and failure process of shear bond, the failure mechanism of shear bond is proposed. Finally, the design of the shear key put forward the corresponding optimization recommendations.