Abstract: This paper introduces the supporting structure for the deep excavation for a water gate and its deformation monitoring points for the adjacent complex environment. The importance of the deep horizontal displacement monitoring points to the stability and safety of the adjacent flood walls, municipal utility pipelines and surroundings are evaluated. The monitoring results indicate that the deformations surrounding the excavated area were monitored throughout the entire excavation and the deep lateral deflection of the soil is the major factor that affecting the adjacent environment. The construction of the jet grout cutoff wall has a significant impact, and the rheological characteristics of soft soils are also affecting the deformation of the adjacent environment. This article analyzes the factors affecting the environmental deformation surrounding the excavated area through specific monitoring points during the construction and proposes some viable measures to control the deformation. These measures have positive significance in further reducing environmental deformation of the surroundings.

Key words: Soft Soils, Water Gate, Deep Excavation, Lateral Squeeze, Excessive Pore Water Pressure