Air injection into the soil to temporarily alter the groundwater flow direction

Abstract

In underground construction or maintenance projects in high-groundwater areas, groundwater management or dewatering is a critical process to enable construction activities. Common methods include directly pumping water out of the work area or pumping from surrounding areas to lower the groundwater level. However, managing the pumped water depends on the availability of space, and in cases where there is insufficient room for water retention ponds surrounding the construction area, the discharged water may be released into public areas, potentially causing social or environmental impacts. This study aims to develop a novel dewatering method using air injection techniques, where pressurized air is injected into the soil to temporarily alter the groundwater flow direction, preventing groundwater from entering the construction area and reducing issues related to managing extracted water. Laboratory experiments simulated the proposed method using tempered glass fragments as a substitute for sandy soil (cohesionless soil), with the material’s transparency allowing for clearer observation of groundwater flow. This test result demonstrates the behavior of 6-bar Air injection added to porous material at a level of up to 8 centimeters from outlet of air injection. The findings are expected to support the development and application of this technique in underground construction and maintenance projects, improving groundwater management efficiency and minimizing environmental impacts.