摘要
接头是沉管隧道中最薄弱的一环,在受到地震和不均匀沉降等作用下,接头会发生横向变形,并通过接头中的剪力键传递。目前,国内外沉管隧道管节接头变形规律的研究较少集中在剪力键上,更缺少管节接头整体力学性能试验数据的支持。根据沉管隧道接头构造设计特点,该文提出了一套测试接头压剪承载力和破坏模式的破坏试验方法和加载方案,并开展了几何比尺为1∶10的管节接头压剪试验,研究接头在低周往复剪切荷载下的力学性能,记录其荷载-位移曲线,最终获得接头压剪刚度曲线。试验结果表明,管节接头和单个剪力键的承载力分别是310 k N/355 k N(正/负向)和88 k N,均比设计承载力高。而接头剪力键的破坏模式主要表现为局部翘曲破坏和凸榫根部拉裂破坏。
When the immersed tunnel is subjected to earthquakes, differential settlement or/and other loadings, transversal deformation occurs and is transferred by the shear keys in the immersion joint, which is deemed to be the weakest part in immersed tunnel. So far, in consideration of researches on immersion joint, only few of them focus on shear keys and most of them are lack of support from the experiments on the behavior of the whole immersion joint. Based on the characteristics of the immersion joint, a testing method and a loading scheme are proposed to obtain the shear capacity and failure mode of the joint. With the geometric scale of 1:10, the model was designed and the compression-shear test was carried out to investigate the mechanical behavior of the joint subjected to low frequency cyclic loading. The load-displacement curves of the joint and the shear stiffness are recorded. The results indicate that the shear capacities of the joint and one single shear key are 310 k N/355 k N(+/-) and 88 k N respectively, which are both higher than the designed values. The local warping failure and tension failure in the root of tenon are regarded as the failure mode of the concrete shear keys.
引文
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