Design and practice of roundabout method for large-scale deep excavations in soft soils

Based on the case of bracing structures for excavation of Dongfangwanguo Enterprise Centre in Shanghai, a new set of design and construction method, roundabout method is introduced. The construction period is greatly reduced by using the method, and the project cost is also controlled by reducing a great amount of temporary bracing structures in the excavation. This new technique is able to effectively control the displacement of bracing structural system in deep soft soils. The field monitoring data show that there is no oversized displacement and leakage in the deep excavation, and subsequently the safety of the adjacent structures is ensured. This successful case may provide some useful reference for the design of similar projects.