# Synchronous Grouting Analysis of Shield Tunneling through High Water Pressure Fault Fracture Zone
## 6 Conclusions  
(1) According to the on-site water and soil pressure monitoring results, synchronous grouting at the shield tail is the main cause of changes in soil and rock pressure in the fault fracture zone area, which is consistent with the numerical model analysis results. The trend of changes in soil pressure and pore water pressure during shield tunneling is basically consistent. According to the different positions of monitoring points at the distance of shield tunneling, it can be divided into main impact area, secondary impact area, and non-impact area. When the shield tunneling machine approaches, the water and soil pressure changes strongly. When the shield tail passes by, there is a maximum excess pore pressure value. When the shield tunneling machine moves away, the water and soil stress shows a downward trend. The impact of synchronous grouting decreases with the increase in excavation distance.  
(2) The difference in the properties of surrounding rocks is the main reason for the variation of water and soil pressure. Due to differences in permeability, the variation pattern of pore pressure in the fault fracture zone is significantly different from that of the original rock. The pore pressure in the induced fracture zone area increases rapidly and has a wider impact range and can dissipate quickly after grouting is completed in a short period of time.  
(3) According to the numerical model analysis results, after crossing the surrounding rock of the fault fracture zone, the maximum settlement of the rock and soil along the tunnel is concentrated in the fault fracture zone area, and the settlement of the lower wall fracture zone is relatively larger than that of the upper wall fracture zone.  
(4) The analysis of grouting parameters shows that the grouting pressure has a strong impact on the variation of pore pressure, while the grouting pressure has a small impact on the final settlement deformation of rock and soil and needs to be maintained within a certain reasonable range; the amount of grouting has a certain effect on resisting the settlement of rock and soil. For areas with fault fracture zones, the amount of grouting should be appropriately supplemented; under high water pressure conditions, the impact on the deformation and settlement of the original rock is relatively small, while the impact on the settlement of fault fracture zones is greater.  
[PERSON] and [PERSON] proposed the core ideas of the manuscript and made the final revisions to it; [PERSON] and [PERSON] wrote the original manuscript; [PERSON] organized and translated the current manuscript; [PERSON], [PERSON], [PERSON], [PERSON], [PERSON] and [PERSON] provided experimental data and graphs for the manuscript. All authors have read and agreed to the published version of the manuscript.  
This research was funded by Guangdong Province Key Field R&D Program Project (Nos. 2022B0101070001, 2019B111108001), the National Natural Science Foundation of China (project Nos. 52078304, 51938008 and 52090084), Shenzhen Fundamental Research (No. 20220525163716003), Shenzhen Science and Technology Program (KQTD20200909113951005), and the Pearl River Delta Water Resources Allocation Project (CD88-GC022020-0038).  
The authors confirm that the data supporting the findings of this study are available within the article.  
The authors declare no conflict of interest.