Correlation Analysis of Evaluation Indicators for Shield Tail Sealing Grease Waterproof Performance

Abstract

Objective The performance of shield tail grease significantly influences the effectiveness of the shield tail waterproof seal. While there are numerous performance indicators for shield tail grease, the relationship between these indicators and the waterproof performance of the shield tail is not yet clarified. It is essential to conduct research on the correlation between various grease testing indicators and waterproof performance. Method Four typical shield tail grease materials are selected for pumpability tests, consistency tests, and water pressure sealing tests. Test data for pump delivery, penetration depth, holding pressure time, and waterproof failure pressure are obtained for the four types. Using a self-designed shield tail waterproof performance test device, waterproof performance tests for shield tail grease are conducted. The Pearson correlation coefficient method is employed to analyze the correlation between the four performance indicators and waterproof performance. Result & Conclusion Grease with long fibers can resist certain stresses and exhibit good pressure-holding performance. There is a significant difference in the waterproof failure pressure of different shield tail greases, with the pressure ranging from 0.41 and 0.70 MPa. Not all shield tail greases can meet the design waterproof pressure of 0.60 MPa, and grease performance testing should be considered during grease selection. The penetration depth shows a highly negative correlation with water pressure sealing performance and waterproof failure pressure.

Keywords

• metro tunnel construction
• shield tail grease
• waterproof sealing performance
• performance indicator
• correlation analysis