Stability Analysis of Soil Flow Protector and Design Method for Estimating Optimal Length

Abstract

Underground cavities can develop below structures, leading to ground settlement and hindering the development of urban infrastructure. Soil flow protectors (SFPs) have been developed to prevent and alleviate problems due to the formation of such cavities. In this study, we performed scaled model experiments to develop a design method for an SFP with an adequate safety factor under different installation lengths of its upper and lower parts in sandy ground. The installation of the SFP reduced the average surface settlement ratio to the range of 0.44–0.72, thus demonstrating its effectiveness in reducing ground settlement. In addition, we proposed a relational equation for determining the optimal length ratio of the SFP and the settlement ratio. An analysis of the influencing factors showed that the lower part of the SFP influenced the settlement reduction, whereas the upper part influenced the stability of the SFP depending on the ground settlement ratio. Finally, we have proposed an optimal length equation for the SFP and presented a flowchart for the design method. The results of this study can serve as a design basis for the efficient construction of infrastructure.

Keywords

• scaled model experiment
• sandy ground
• soil flow protector
• design method
• optimal length ratio
• safety factor