The waterstop is a core sealing component of the shield rubber dam, known as the dam’s "sealing guardian". It directly determines the seepage prevention effect and operational safety of the dam, serving as a key part for long-term project operation and maintenance.
The overall design life of the shield rubber dam is 50 years. The aging of rubber waterstop follows a pattern of fast initial decay followed by slow deterioration. Its performance drops most rapidly within the first 10 years of service to about 50% of the original level, yet the seepage prevention function remains available. Afterwards, the aging rate slows down greatly, resulting in a far longer replacement cycle than ordinary rubber parts with outstanding durability.
The shield plate structure of the shield rubber dam provides physical protection, blocking ultraviolet radiation and impacts from floating debris, which greatly slows the aging of the waterstop and outperforms conventional rubber dams. Nevertheless, factors including repeated bending deformation during dam operation, sediment abrasion in river channels, and alternating high and low temperatures will continuously accelerate rubber aging and shorten the actual service life.
Under normal working conditions, the effective service period of the waterstop can cover most of the design life of the shield rubber dam. Daily inspections shall focus on critical areas such as anchorages and joints to detect leakage and cracking risks, and refined maintenance can delay performance degradation.
In general, the waterstop of shield rubber dam is not a permanent component, but it features stable performance attenuation and excellent service life. The dedicated shield plate lays a solid foundation for its durability, while regular inspection and scientific maintenance are critical to extend its service cycle, guarantee reliable anti-seepage performance and long-term stable operation of the project.
