Key Waterproof Technologies for Integral Underground Station with Assembled Superposed Structure in Urban Rail Transit

Abstract

[Objective] In order to improve the waterproof performance of the integral underground station with assembled superposed structure (abbreviated as AS station) and help its application in urban rail transit projects, it is necessary to study the key waterproof technologies for such underground station. [Method] The concrete anti-seepage and anti-crack technology, the waterproof scheme of the station envelope and the detailed structure of the AS station are studied. [Result & Conclusion] The high crack risk of prefabricated panel wall components exists mainly in the surface of panel wall with thickness of 500 mm and 350 mm, the structure center and surface with thickness of 100 mm. The cooling rate of prefabricated roof slab should not exceed 2.2 ℃/h. The duration of steam curing of prefabricated panel wall from 45 ℃ to 10 ℃ should not be less than 24 h, and the cooling rate should not exceed 1.5 ℃/h. In the superposed structure system, the construction technology of water-washed aggregate should be adopted for the components mainly subjected to tension, and the chisel technology for the components mainly subjected to shear. The control of temperature field and expansion process can effectively reduce the cracking of concrete and improve the waterproof performance of the station. The external waterproof schemes for the main structure of the station, the design of the circular compression seal strip, the "wet-buried" retracting of the compression seal joint and the bonding measures of the prefabricated panel at the bracket position all improve the waterproof performance of the station joints. The successful application of this scheme in Nanmen Station of Wuxi-Jiangyin-Jingjiang Intercity Rail Transit line promotes the application of this type of underground station in urban rail transit projects, and helps to shorten the construction period, improves the on-site labor productivity, and promotes the transformation and upgrading of the construction industry.

Keywords

• urban rail transit
• as station
• key waterproof technology