###### Abstract  
With the rapid development of urban rail transit and underground space construction, the advantages of the concealed excavation method are gradually highlighted in the urban center area affected by a complex engineering environment. At present, the pipe curtain method with a flexible section and wide application of the soil layer is being widely used in engineering, but the research on the stability of the excavation face during the construction of the pipe curtain method in soft soil areas still has not formed a complete system. Therefore, this paper analyzes the stability of the excavation face under different reinforcement conditions and the influence of different spacing, numbers, and strength of MJS (metro jet system) zones on the stability of the excavation face of the pipe curtain method based on the actual project of the Guiqiao Road Station of the Shanghai Metro, China, and gives a reference for the reinforcement of the palm face in the excavation process of the pipe curtain method in soft soil areas. The study shows that the safety coefficient of the excavation face decreases with the increase in the slope angle of the excavation face, with the increase in spacing of the MJS zone, and with the increase in height of the MJS zone arrangement, while the safety coefficient of the excavation face increases with the increase in strength of the MJS zones themselves and the increase in the strength of the soil between the MJS zones. Further, the machine learning model is applied to predict the stability of the excavation face under different cases, and the relevant fitting accuracy is above 0.9, which can predict the stability of the excavation better. metro jet system; horizontal reinforcement; safety factor; machine learning +
Footnote †: journal: Applied Sciences  
**Citation:** [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON] Stability Analysis and Safety Factors of the excavation Face of a Pipe Screen Tunnel in a Soft Soil Area. on an underpass with a rectangular arch section. [PERSON] et al. [9] took the pipe curtain structure composed of larger diameter steel pipes as the research object and used numerical simulation to establish the corresponding soil layer model to study the settlement pattern of soil layer, the influence process of face settlement, and the force deformation process of steel pipes. [PERSON] et al. [10] used a Beijing subway tunnel located in a sand and cobble stratum as the research background and explored the application research of the pipe curtain method in the sand and cobble area by using in situ field tests. [PERSON] et al. [11] took the Gongbei tunnel project of Hong Kong-Zhuhai-Macao Bridge as the research background, designed three different freezing schemes for the project using different style combinations of solid and empty pipe jacking, and compared the schemes. [PERSON] [12] investigated the comprehensive technology of the pipe screen roofing end and receiving end face for the construction of the pipe screen in the Gongbei Tunnel of the Hong Kong-Zhuhai-Macao Bridge. [PERSON] et al. [13] proposed a large pipe curtain construction method for deeply buried subway stations in water-rich strata, and their study showed that the deformation of the pipe curtain structure can be relatively reduced when using the inverse method for construction in this project. Jet grouting technology is a hydraulic soil mixing method used to improve the strength of soft soils due to its advantages, such as rapid construction and significant increase in the strength of weak soils [14; 15; 16; 17], it has been widely used in the reinforcement construction of geotechnical engineering structures, such as slope reinforcement [18; 19] and ground reinforcement before tunnel excavation [20; 21]. High-strength jet grouting is a form of jet grouting technology that forcibly mixes and decomposes the soil, thus forming a cement slurry and soil mixed with the cement soil solidification body [22; 23; 24; 25].