Evaluation of a Superabsorbent Polymer for Plugging Karst Pipe Type Water Inrushes

In this study, experimentally simulated ultra-rapid and super-large water inrushes was plugged effectively using superabsorbent polymers (SAPs). The SAPs are mainly composed of sodium polyacrylate and possess a core–shell structure at the micro-level, as described through multiple characterization methods. Swelling and flow experiments in a purpose-built apparatus revealed that the SAP can absorb ≈ 300 times more water than its own weight and displays an excellent water retention capacity. Most importantly, when evaluated in a visual model test, the SAP effectively plugged gushing water with high water pressure and a large and/or rapid flow rate; furthermore, the plugging time can be adjusted. Through the experiments, we delineated the plugging mechanism. These research results have important scientific significance and engineering value for reducing and controlling the occurrence of water inrush disasters in karst areas.