Multi-criteria evaluation model of rubber sealing gasket for shield tunnel joint

Rubber sealing gasket materials play a critical role in the waterproof design of joints in shield tunnels. Traditional methods for selecting sealing materials and profiles often rely on empirical analogies, lacking a quantitative evaluation system. Inadequate design of sealing solutions has led to issues such as tunnel leakage and segment cracking. To address this issue, a multi-criteria decision-making model based on the TOPSIS method is proposed to balance the requirements of waterproof performance, assembly performance, and economic efficiency in sealing solutions. Firstly, the geometric dimensions of 60 sealing gasket profiles are collected in detail. A dataset of 540 sealing solutions is constructed through finite element simulations, considering variations in material hardness and groove filling ratio, which forms the data foundation for the evaluation model. Key design thresholds are then introduced, allowing the model to adapt to the design requirements of different tunnel engineering projects. Moreover, the diminishing marginal effect is applied to the data processing to refine the evaluation model, addressing the potential overemphasis on a single performance criterion in traditional approaches. A game theory-based combined weighting strategy is employed to determine the overall weights of five performance indicators, ensuring a scientifically balanced integration of multiple weighting methods. The results from the case study demonstrate significant performance differences between the alternatives that meet the design thresholds. The optimal solution achieved a 44.268 % increase in waterproof pressure, 45.83 % improvement in joint gap tolerance, 24.01 % increase in maximum deflection force, 5.53 % reduction in groove filling ratio, and 55.53 % reduction in cost compared with the least effective solution, leading to a synergistic enhancement of the waterproof, assembly, and economic performance of the sealing solution. Overall, the proposed methodology supports shield tunnel engineering in selecting the most suitable sealing solution and provides a foundation for the design and performance enhancement of gasket materials.