Experimental study of groundwater level variation in soil slope using air-injection method

• Published in: Géotechnique letters 2018-06, Vol.8 (2), p.144-148
• Main Authors: Xie, W., Shang, Y., Lü, Q., Jiang, H., Wei, Z.
• Format: Article
• Language: English
• ISSN: 2045-2543; 2045-2543
• DOI: 10.1680/jgele.18.00005

The rising of groundwater level induced by intense rainfall has significant influence on the slope stability. A new drainage method for landslide mitigation, namely the air-injection method, is proposed in this paper to control the quick rising of the groundwater under heavy rainfall to reduce the risk of landslides in a situation of emergency. A large-scale slope model is established in the laboratory to study the influence of the air-injection method on the groundwater level variations. The test results indicate that air injection divides the slope into three zones and forms a low permeability unsaturated zone to prevent the upstream groundwater flowing to the downstream slope. Two phases are identified during the air injection, (a) a formation phase of the unsaturated zone and (b) a steady-state phase of the unsaturated zone, and the unsaturated zone continues to intercept the upstream groundwater flow within a certain period of time after air injection is ceased. Furthermore, increasing the injection pressure appropriately can enhance the effectiveness of the air-injection method in intercepting groundwater.