Polyurethane foam, when used as a compressible layer in deep soft rock tunnels, offers a feasible solution to reduce the support pressure on the secondary lining. The foam spraying method using sprayed polyurethane material is convenient for engineering applications; however, the compressive behaviour and feasibility of sprayed polyurethane material as a compressible layer remain unclear. To address this gap, this study conducts uniaxial compression tests and scanning electron microscope (SEM) tests to investigate the compressive behaviour of the rigid foams fabricated from a self-developed polyurethane spray material. A peridynamics model for the composite lining with a polyurethane compressible layer is then established. After validating the proposed method by comparison with two tests, a parametric study is carried out to investigate the damage evolution of the composite lining with a polyurethane compressible layer under various combinations of large deformations and compressible layer parameters. The results indicate that the polyurethane compressible layer effectively reduces the radial deformation and damage index of the secondary lining while increasing the damage susceptibility of the primary lining. The thickness of the polyurethane compressible layer significantly influences the prevention effect of large deformation-induced damage to the secondary lining within the density range of 50-100 kg/m3. In accordance with the experimental and simulation results, a simple, yet reasonable and convenient approach for determining the key parameters of the polyurethane compressible layer is proposed, along with a classification scheme for the parameters of the polyurethane compressible layer. (c) 2025 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/ 4.0/).