waterproof in subway construction

Metro waterproofing is an important part of the quality of subway construction, waterproofing is good or bad related to the use of the subway, durability, safety, which requires the subway to have good water resistance, mainly in the following areas.

    (1) good waterproofing is the normal operation of the subway needs. Metro station is crowded, passengers get off and transfer sites, but also the subway staff and commercial outlets staff long-term work place, but also the location of mechanical and electrical equipment, which requires that the subway station must be kept dry, to ensure that the comfort of staff, items Do not mildew; while the subway tunnel is to check the maintenance staff's workplace, while maintaining the power lines, orbits, communications, signal components from moisture damage damage, and also need to maintain a good waterproof state.

    (2) Good waterproofing is the requirement of the firmness and durability of the project itself. Groundwater, especially aggressive groundwater damage to the concrete structure itself is very large, it not only with the chemical reaction of concrete, resulting in reduced strength of concrete, but also to the structure of the internal reinforcement erosion, a direct result of structural load-bearing capacity decline.

    (3) Good waterproofing is the need of environmental protection and water resources protection, and is to avoid the need of geological disasters. Blind drainage can lead to withered vegetation on the ground, which is also a waste of precious urban underground resources. What is more serious is that the groundwater table will be degenerated and ground surface will sink due to the decrease of groundwater level. So that the formation of uneven settlement or destruction of buildings. For the above reasons, the new version of "Subway Design Code" (GB 50157-2003) abolishes the drainage in the "anti-bleaching combination" in the principle of anti-drainage, stressing that "rigid and soft combination, multi-line of defense" .

    (4) Good waterproofing plays an important role in reducing the maintenance costs of the subway operation phase. Leakage from the subway will not only make the rail corroded and damaged, but also damp internal environment will aggravate the mildew damage of the interior decoration of the subway, meanwhile it may lead to the safety accident of the subway power supply line, leaving a hidden danger to the operation and maintenance. Leakage treatment itself is often ineffective at time-consuming work.