English：

Taking the foundation excavation of a comprehensive transportation hub in Beijing as an example, this paper analyzed the spatiotemporal evolution and variability of rebound deformation during the excavation of an ultralarge deep foundation excavation. Monitoring and analysis revealed that during the early stages of excavation, the average uplift of the columns was 60mm, with local values exceeding 90mm—far exceeding that of ordinary foundation excavation of the same depth. Through orthogonal simulation experiments designed to analyze factors affecting foundation excavation deformation, it was determined that excavation depth and groundwater are the key factors influencing column uplift. Onsite excavation records also indicate that the excavation volume in July was enormous. The intense unloading effect caused by the rapid excavation of large volumes of soil was the primary cause of the abnormal early uplift of the columns. Furthermore, the cyclical rise in the groundwater level caused by exceptional rainfall had a significant impact on the rebound at the bottom of the foundation excavation. Reducing the excavation speed and implementing timely dewatering can effectively minimize excavation rebound deformation.