English：

This paper took a transportation hub project in Beijing as its case study. Based on hydrogeological conditions, construction conditions, excavation methods, and support schemes, onsite monitoring was conducted to track the deformation of diaphragm walls, ground surface settlement, and column deformation during the coordinated excavation of adjacent excavations. The data were analyzed to investigate the deformation patterns of support structures in ultralarge deep foundation excavations during coordinated excavation. Furthermore, PLAXIS 3D numerical simulations were conducted to analyze foundation excavation deformation under various conditions, leading to the identification of the optimal construction plan for controlling deformation. The results indicate that, due to the influence of excavation in the adjacent foundation excavation, the maximum deeplevel horizontal displacement at the central measurement point of the retaining wall was 13mm, which was less than the 16mm recorded at the corner measurement point adjacent to another foundation excavation, indicating a reduced “corner effect”. Surface settlement behind the wall was closely related to the deformation of the retaining wall. Under the influence of excavation in the adjacent foundation excavation, the displacement of the columns perpendicular to the direction of the common diaphragm wall and in the eastwest direction generally decreases from east to west, with the maximum eastwest difference being approximately 16mm, which does not conform to the “corner effect”. Under conditions of coordinated excavation of two adjacent excavation pits, the use of reversesequence excavation (postexcavation) effectively controlled differential deformation of the columns, with eastwest uneven settlement of only 0015‰. The use of simultaneous excavation effectively controlled the maximum deformation of the retaining structure.