Application of interception and drainage anti-floating system in treatment of uplift accidents

It is very complicated to deal with the uplift accidents of underground structures, because the reconstruction of uplift piles or anchors will damage the wide range of bottom slabs, while draining water blindly to relieve pressure may have a bad impact on the environment. The interception and drainage anti-floating system is a good solution to deal with these uplift accidents. The concept of this system is to intercept and drain water by use of the cutoff wall around the underground structures to form a relatively closed seepage environment and several relief wells on the bottom slab. This system can discharge water automatically with the help of controlling and monitoring equipments. The hydraulic gradient around the relief well decreases dramatically due to the adoption of a large well diameter that offers convenience to the later cleaning and maintenance work, which eliminates the hydraulic condition of well clogging. The relief well consists of several prefabricated non-fines concrete well rings installed by crane, so the construction process is very simple. This system has been successfully applied to the treatment of the uplift accident of an underground garage. The monitoring results show that the flow rate and hydraulic head can be controlled, and the operating cost is low.