Abstract: In this paper, the numerical methods are used to study the stressstrain relations of deep excavation support system in confined spaces in urban area. The main feature of the excavation support system studied in this paper is that it forms an entire body with the surrounding buildings to resist the deformation induced by the excavation. The main conclusions are as follows: the underground garage reduces the volume of the upper soil behind the supporting soldier piles and increases the lower soil load, resulting in a wavy shape of the supporting piles as an entire body after the excavation is completed. The deep excavation has a small impact on the underground garage, the weak position of which is the column. The impact of the underground garage on its lower soil during excavation was approximately 0.15 times its height. The above results provide a new feasible solution for the excavation support under the narrow space in the city, and have certain guiding significance for the deep excavation projects.

Key words: Excavation Supporting, Proximity Structures, Pile Anchored Support, FLAC 3D