Application of a new retaining structure in deep underground projects adjacent to sensitive environment

Both the TRD construction method and dual-purpose wall method are newly developed retaining techniques for excavations. Adjacent to the excavation of Nanjing Ecological Park, there are several streets, a metro station, tunnels and a lot of municipal pipelines. The general information of the project and the design work of the deep excavation are introduced. In particular, the details of the TRD construction method used for protecting the metro station and the dual-purpose wall method adopted for energy saving purpose are introduced. The field monitoring results on the performance of the excavation are discussed as well. With the help of these new techniques, the excavation has been successfully completed. The monitoring results show that the influences of the excavation on the adjacent environments are limited by using the TRD construction method and dual-purpose wall method.