Experimental study on bulge deformation of geotextile under ring-restrained conditions

Geotextile layers are arranged on and below the geomembrane to prevent the geomembrane from being punctured and damaged. The geotextile not only plays a role in physical protection, like anti-puncture but also makes a great difference to the mechanical properties of the geomembrane’s air expansion deformation. In this paper, the bulging deformation of geotextile is simplified as spherical bulging deformation under ring-restrained conditions. Using the special bulging deformation test equipment, the bulging deformation experiment of geotextile is realized, the main factors affecting the bulging deformation are analyzed, the law of bulging deformation and failure of geotextile is summarized, the failure mechanism of geotextile and the Influence of geotextile on the properties of geomembrane are discussed, and the following conclusions are drawn. The failure of bulging deformation of geotextiles belongs to tensile failure, which is characterized by fast speed and high strength. The typical failure mode is spindle-shaped cracks distributed along the crown, whose failure mechanism belongs to tensile failure produced in weak areas. The bulging deformation of the geotextile shows nonuniformity, with the largest deformation at the crown top and the smallest deformation at the ring constraint. When the geotextile is covered on the geomembrane, bulging pressure is shared by both the geomembrane and the geotextile. At the initial deformation stage, the geomembrane replaces it, and then the geotextile bears more internal pressure and plays a decisive role till destruction.