Innovative use of geosynthetics for repair of slope failures along irrigation/drainage canals on soft ground

摘要

Slope failures are so frequent along in irrigation canals on the soft clay foundation. The innovative use of dual function geotextile to solve this problem is presented in this paper. The dual function geotextiles not only act as earth reinforcements but also function as drainage paths to dissipate the excess pore pressure and hence increase in the strength of the soft foundation with time. The theoretical background for the analysis of slope stability as well as the interaction behavior between the geosynthetics and soil are examined. Based on the shear test results of the high strength geotextile reinforcement PEC200 embedded in the soft clay and weathered clay with different inclination angles, it is concluded that at a particular initial inclination angle, the resisting force due to geotextile is mainly controlled by the strength of the soil, regardless of the effective normal stress. The higher the soil strength, the greater the resisting force and the lower the limiting strain. The inclination factor, I_f, is only dependent upon soil strength, irrespectively of effective normal stress and initial inclination angle. Finally, the application of the high strength geotextile reinforcement for protection of the slope failure and the analysis are presented. There are two considerations for the slope stability analysis: A) with limitation of the foundation settlement and B) with the allowable large settlement.