Abstract: To investigate the mechanical characteristics of the doublesided adhesive interlayer interface of the sprayapplied membrane waterproof lining structure of tunnels constructed by mining method, a test and theoretical analysis are conducted. First, the structure of sprayapplied waterproof membrane lining and the form of interlayer interface are summarized, and the tunnel lining structure is divided into three types, namely, doubleshell linings, compositeshell linings, and singleshell linings. Second, a shear test is performed for the doublesided adhesive interlayer interface in the compositeshell lining structure. The sheardisplacement curves show that the failure of the interface can be divided into two stages: cohesiondamage and friction. In addition, the degree of cooperative stress of the tunnel lining mainly depends on the bonding strength of the waterproof layer and base surface. Finally, based on the constitutive principle of the contact surface and shear test results, the mechanical properties of the doublesided adhesive interlayer interface are further discussed. The results show that the shear mechanical properties and failure criteria can be characterized by the MohrCoulomb constitutive model, and the influence of the base surface roughness can be considered by the shear expansion formula of the shear strength of the contact surface. The research results revealed the shear failure mechanism and mechanical characteristics of the interlayer interface of the doublesided adhesive tunnel lining structure, and relevant parameters are obtained based on the MohrCoulomb constitutive model, which can serve as a basis for determining the failure of the contact surface of the doublesided adhesive sprayapplied membrane waterproof lining.

Key words: tunnel engineering, sprayapplied membrane waterproof lining, layer interface, shear test, mechanical properties