Influence of Rainwater Infiltration in Partial Anti-Seepage Bioretention on Adjacent Municipal Roads in Different Collapsible Grades Loess Sites

It is practical to carry out sponge cities to manage rain and floods in collapsible loess areas where water resources and water disasters are prominent. The infiltration laws of the partial anti-seepage bioretention in collapsible loess fields are helpful to ensure the effectiveness and safety of sponge city, which were learned from the field test and numerical model. The seepage field and displacement field of loess sites with different collapsibility grades were compared during rainwater infiltration of the bioretention with the numerical model; the suitability and optimization suggestions for foundation treatment of this structure in various sites were proposed. It is found that the infiltration characteristics can be divided into three stages, and the infiltration range of bioretention increases with increasing infiltration time under the same site type, and the higher the collapsibility level of the site is, the more significant the rise in infiltration range. The settlement of adjacent roads in class II and III collapsible fields is far greater than that in class I and is greater than the settlement standard. The facilities’ bottom part foundation can be replaced to ensure the functionality of the facilities and the safety of the surrounding roads in the actual project.