Investigating the influence distance of low-pressure fluid injections in low-permeability soils

This study investigates shallow, low-pressure fluid injections in low-permeability soils for applications such as soil stabilization and groundwater remediation. Unlike conventional high-pressure techniques, the research focuses on pressures below 100 kPa, targeting shallow depths and lightly loaded structures. Field experiments were conducted using borehole injections, with moisture changes monitored at varying distances. These data were used to calibrate a finite element model, which was then employed to explore the effects of soil properties and injection pressures on the extent of fluid dispersion. Results show that in expansive soils with low permeability, high matric suction significantly increases the lateral influence of injected fluids over time, while variations in low injection pressures had minimal impact. The study provides charts correlating influence distance with permeability, suction, and pressure, offering practical guidance for low-pressure injection planning in clayey soils.