Rainfall is one of the most important factors affecting slope stability. This study employed multi-source monitoring devices to observe the slope displacements in real time under rainfall infiltration and performed numerical simulations to investigate the effects of different rainfall conditions and anti-slip pile configurations on slope stability. Specifically, multi-source monitoring operations were conducted on the high and steep slopes along the Yunmao Expressway. Real-time data on slope deformation, rainfall, and displacement at the tops of anti-slip piles were collected and analyzed, and numerical simulations were conducted using Geo Studio finite-element software. The findings indicated that abrupt deformation of slopes occurs once a threshold rainfall amount is surpassed and sustained over a specific duration. Slope displacement decreased with increasing slope depth above the potential slip fracture surface, with a more rapid reduction in deformation rates observed in slopes reinforced with anti-slip piles. For equivalent rainfall amounts, short-duration, intense rainfalls led to a rapid decrease in the slope safety factor, which also recovered rapidly once the rainfall ceased, in contrast to long-duration, mild rainfalls. The presence and location of anti-slip piles significantly influenced slope stability; therefore, project implementation should carefully consider factors such as cost and duration for optimal decision making.

As foundation pit engineering is developing towards larger and deeper designs, the requirements for controlling excavation-induced deformation are becoming increasingly stringent, particularly in complex urban environments and soft soil areas. In recent years, numerous foundation pit projects have incorporated Hydraulic Servo Steel Support (HSSS) to actively manage the axial forces of the internal supports, which has achieved significant reductions in the displacement of the retaining structures (δ_D). An investigation of engineering cases in soft soil areas revealed that the average ratios of the δ_D to the excavation depth (H) for foundation pits with and without servo control systems were 0.11% and 0.38%, respectively. This study analyzed the monitoring data related to the δ_D, the deformation of the soil outside the foundation pit, and the changes in the axial force of the internal supports in a deep foundation pit located in Hangzhou City, China. The results indicated that employing the zoned excavation and HSSS effectively controlled the δ_D. During the excavation stage, the HSSS ensured that the δ_D remained below the design threshold, although some deformation persisted during the dismantling stage. Additionally, adjustments to the axial force of the internal supports affected the axial force of the adjacent supports, with a common occurrence of reverse pulling force in the first-layer supports due to the action of the HSSS. Therefore, further optimization of the HSSS is necessary to enhance control effectiveness.