# Study on Disturbance Mechanism of Squeezed and Non-Squeezed Soil Piles on Soft Soil Foundation
## 6 Conclusions  
A comprehensive comparison of the disturbance effects of pile driving on soft soil foundations for both squeezed and non-squeezed soil piles was presented. Based on the analyses of the pile disturbance mechanism and hypothesis, as well as the indoor test results, the numerical simulation of the single pile driving processes for the hydrostatic pile, bag grouting pile, and bored pile were carried out by using FLAC\({}^{\text{3D}}\). Specifically, a novel construction method for numerical models was proposed and employed to simulate the mechanical processes of different pile types under standard grids. The evolution characteristics of the soil displacement field, stress field, and disturbance range under single-pile disturbance for the three types of piles were compared and studied, thus revealing the disturbance effects of different types of piles on the soil. Specific conclusions are drawn:  
(1) An analysis of the disturbance mechanisms associated with squeezed and non-squeezed soil piles indicates that their respective disturbance effects on the soil are the squeezing effect and unloading effect. Based on this, a numerical simulation study on the soil disturbance caused by pile installation is conducted.  
(2) Simulative findings demonstrate that there are notable differences in the effects of three types of piles on soil disturbance. The two types of squeezed soil piles have caused significant disturbances to the soil displacement field, particularly in the horizontal direction. However, the impact on the soil stress field is relatively small. Among them, the hydrostatic pile has a larger disturbance magnitude and range than the bag grouting pile. For non-squeezed soil piles, the bored pile causes the smallest variation in the soil displacement field during the pile driving process. Moreover, the stress field of the soil remains mostly unchanged.  
(3) The comparison of the disturbance effects of the three types of piles on the soft soil foundations has been carried out by quantifying the disturbance range of the stress field and displacement field of soil. The results reveal that the disturbance range of horizontal stress and deformation is greater than that of vertical stress. Normalization has been performed on the horizontal stress and deformation disturbance ranges of hydrostatic piles, bag grouting piles, and bored piles. The horizontal disturbance values of maximum horizontal stress for all three types of piles are approximately 1/5 of the pile length above the pile tip, with normalized values of 7.6, 5.5, and 3.5, respectively. As for the maximum horizontal deformation disturbance range in the horizontal direction, it occurs near the ground surface, and the normalized values are 15.2, 7.5, and 1.1, respectively. Consequently, the disturbance effect of the hydrostatic pile on soil is found to be the greatest, followed by the bag grouting pile and the bored pile.  
Conceptualization, C.L.; methodology, Q.T.; software, M.H.; validation, R.W. and L.H.; formal analysis, R.W.; investigation, R.W.; resources, C.L. and Q.T.; writing--original draft preparation, C.L.; writing--review and editing, Q.T.; visualization, M.H. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This work was funded by the Research Project of China Railway Siyuan Survey and Design Group Co., Ltd. (No. 2022K003), the National Natural Science Foundation of China (No. 42007268), the Postdoctoral Innovation practice positions in Hubei Province (No. RCXM2022002) and the China Postdoctoral Science Foundation (No. 2021M703002).  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Not applicable.  
**Acknowledgments:** The authors would like to thank [PERSON] for his help on the source materials, his view points, and writing.  
**Conflicts of Interest:** The authors declare no conflict of interest.