盾构隧道管片混凝土接触面力学性能研究

Study of the Interface Mechanical Properties of Concrete Segments in Shield Tunnels

  • 摘要: 盾构隧道混凝土管片接触面的力学性能直接影响到衬砌的受力与变形,进而影响隧道的防水与安全。文章开展了混凝土接触面的压缩与剪切试验,研究了不同接触面法向力、不同剪切速率及循环剪切作用下接触面的力学性能。结果表明:随着接触面法向名义应力的增加,接触面法向刚度呈先指数增长后趋于稳定特征,而切向摩擦系数近似呈负指数增长;随着剪切速率的增加,接触面动摩擦系数先减小后趋于稳定;在循环剪切作用下,接触面法向刚度与切向摩擦系数均呈现先增长后趋于稳定的特点。基于接触力学方法,根据试验结果拟合得到了接触面法向力学模型与切向摩擦系数模型。研究成果对管片接头的设计及衬砌结构的受力分析具有一定的参考价值。

     

    Abstract: The interface mechanical properties of concrete segments directly affect the stress and strain of the linings in shield tunnels and further affect tunnel waterproofing performance and safety. Therefore, compression and shear tests of the concrete interface were carried out to study the mechanical properties of the interface under different normal forces, different shearing rates and cyclic shearing. The results show that:1) with an increase of normal nominal stress on the interface, its stiffness experiences exponential growth at first, then becomes stable, while the tangential friction coefficient approximately experiences a negative exponential growth; 2) with an increase of the shearing rate, the dynamic friction coefficient decreases at first and later becomes stable; and 3) during cyclic shearing, both the normal stiffness and the tangential friction coefficient of the interface exhibit stability after an increase. Based on the contact mechanics, the normal mechanical model and the tangential friction coefficient model of the interface were obtained by fitting the test results. These results can be used as a reference for the design of segment joints and force analyses of lining structures.

     

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