# Research on the Influence Mechanism of Foam Slurry Wall Formation
###### Abstract  
Incorporating foam into slurry can improve its wall-supporting performance. However, the wall formation mechanism of foam slurry under different conditions remains unclear. In this study, numerical simulations were conducted to investigate the influence of soil properties, slurry composition, and pressure gradient on the infiltration process and wall formation effectiveness of foam slurry, which was validated through laboratory experiments. The results indicate that the infiltration process of foam slurry in soil can be divided into three stages--infiltration, clogging, and membrane formation. The time required for slurry membrane formation increases linearly with increasing soil porosity and gradation parameter m, while it decreases with increasing gradation parameter b. An increase in the swelling ratio promotes faster membrane formation, whereas a higher foam content may reduce clogging efficiency. The time required for slurry membrane formation increases quadratically with the pressure gradient. The influence of various factors on the effectiveness of foam slurry wall formation are observed in the following order: soil properties > slurry composition > pressure gradient. When using foam slurry for wall formation, it is advisable to use a relatively high swelling ratio (>5%) and an appropriate foam concentration (approximately 10% to 20%) to improve the stability of the slurry wall.  
foam slurry; wall formation; numerical simulation; soil properties; slurry composition; pressure gradient 2025 15 5253 11 April 2025 5  
engineering. Previous studies indicate that the main factors affecting slurry wall formation are soil properties, slurry composition, and slurry characteristics [3; 11; 12; 13; 14]. For example, adding a certain amount of coarse particles to the slurry can effectively shorten membrane formation time and improve membrane formation efficiency [15]. The relative density of the slurry also significantly affects the morphology and thickness of the mud cake, while increasing slurry viscosity does not lead to obvious changes in thickness [16].  
In addition to physical properties, geochemical factors such as pH, ionic strength, and mineral composition may also influence the behavior of slurry systems. These factors can affect the stability and rheological properties of bentonite-based slurries, potentially altering the formation and structural integrity of the slurry wall. However, in this study, the focus is placed on the physical characteristics of the soil, including particle size distribution, porosity, and gradation parameters, which are considered the dominant factors influencing foam slurry wall formation under the examined conditions.  
However, most existing research focuses on traditional slurries, and the formulation and behavior of foam slurry systems still largely rely on empirical methods [17; 18]. The infiltration and membrane formation processes, mechanisms, influencing factors, and behavioral patterns of foam slurry under varying conditions remain unclear.  
Therefore, this study uses numerical simulation methods to investigate the influence of soil properties, slurry composition, and pressure gradient on foam slurry wall formation, with laboratory experiments for validation.