Seismic responses, damage mechanisms and retrofitting methods for deep braced excavation: Centrifuge test and numerical analysis

The current study investigates the nonlinear seismic responses and damage mechanisms of the deep braced excavation, which has rarely been inspected in previous studies. An effective numerical model is developed based on dynamic centrifuge tests to properly capture the responses and damage of the structure under earthquakes. The model is established by using the nonlinear properties of the material (for both soil and structure) and contact. The procedure of constructing the numerical model including determining the material parameters, boundary conditions, and contact properties is elaborated. The seismic responses of the deep braced excavation during earthquakes with increasing levels of earthquake intensity are clearly investigated and compared with those in the static condition. Then, the damage mechanisms of the structure are stated. Finally, different seismic retrofitting methods are proposed; and, the most effective method is suggested. The findings from this study can provide a clear understanding of the seismic responses, damage mechanisms, seismic retrofitting methods, and also recommendations for seismic design applications of deep braced excavations.