Abstract: To provide foundational data support and reference to the study of the mechanical properties of a closely adhered waterproof layer interface in tunnel lining structures, bond strength and pressureshear tests are conducted based on the characteristics of a sprayapplied waterproof tunnel lining structure to investigate the interfacial shearslip mechanical behavior and properties of polymer waterproof membrane composite specimens. Based on the bond strength tests, the tensile stressdisplacement curves of three types of waterproof membrane materials are plotted; and based on the pressureshear tests, the interfacial shear stressdisplacement curves are obtained. On the basis of the experimentalresult curves, the interfacial parameters of the waterproof layer are calculated, including the shear strength, residualshear strength, shear modulus, shearslip energy, and shear failure displacement, and the influence of the material properties and normal pressure on these parameters is discussed. The results indicate that the shearslip characteristics of the waterproof layer interface are mainly influenced by the type of waterproof membrane material and normal pressure. The material properties of different types of waterproof membranes exert a greater effect on the interfacial shear strength and shear modulus, whereas the residualshear strength, shearslip energy, and shear failure displacement are more affected by the normal stress.

Key words: tunnel lining structure, sprayapplied waterproof membrane, interface characteristics, shearslip failure, stressdisplacement curve