Abstract: The partition wall is a kind of active structure to protect adjacent buildings from deep foundation pits. However there is a lack of theoretical guidance for the design of the structure, and there are few measured data to validate its effects. Based on a large scale deep foundation pit case in soft soil in Hangzhou, a 3-D finite element model considering the construction sequence and soil-wall interaction is presented using the software ABAQUS. The behaviors of soil are assumed to conform to the modified Cam-clay model. The effects of partition walls are studied and validated by the comparison between the analytical and measured results. It is shown that the maximum ground settlement and the total area of the settlement trough can be reduced significantly when the partition walls are constructed between the retaining wall and the adjacent building, and the transverse angular distortions of the building also decrease remarkably. The reduction of the maximum ground settlement and settlement differences at the center of the pit are more obvious than those in the corner. The horizontal displacements of the retaining wall can also be significantly reduced by the partition walls. The closer to the partition wall, the more obvious the decrease of the horizontal displacement of the soils near the ground surface. The active earth pressures on the retaining wall within the depth of the partition walls are smaller when the partition walls are employed. However, the bottom heave of the pit is not affected by the partition walls.