Abstract:The compound soil-nailed wall(CSNW) is a new style of support of foundation pit. This method is widely used in the project practice in recent years because of the excellent behavior and cheap cost. The styles of different CSNWS are introduced,and the research of the deformation mechanism and analysis of global safety of the CSNW employed in soft soil is emphasized. According to the observation of many CSNW projects,it is concluded that the process of crack development on the slope can be divided into three main phases,and the explanation for the cause of each crack phase is described. The countermeasure for dealing with each crack phase is recommended to secure the stability of the excavation. Two methods for calculating the global stability of the CSNW is introduced. One is the “double-circle” slice method,which is a modified method based on the traditional one. The proposition that the failure surface is composed of two circular surfaces is introduced. These two circular surfaces connect smoothly in the position of deep mixing pile. With this proposition,the anti-slide attribution of the soft clay in the passive region is considered properly. This method has already been employed to design a lot of CSNW project. Another method to calculate the global safety factor is shear strength reduction method. This method is getting more and more popular in the region of slope stability analysis. The region of CSNW,the strength of the interface between the soil and nail is not considered. A project calculated with shear strength reduction method is described. It is also pointed out that the method employed in gravity wall analysis is not suitable for CSNW.