Super-absorbent swellable polymer as grouting material for treatment of karst water inrush

TLDR

Grouting is the primary method for controlling water inrush in underground engineering, but conventional cement-based grouts tend to dilute and fail to coagulate under high‑velocity water flows. The study aims to develop a polymer grouting material with a high expansion ratio to overcome these limitations. The new slurry, composed of a superabsorbent polymer, glycerol, and ethanol, rapidly absorbs water, achieving a 1:300 expansion ratio, and its optimal solid–liquid ratio was determined by fluidity tests under varying water quality. In a karst pipeline test, 800 g of the SAP slurry blocked water flow at 0.6 m s⁻¹, outperforming other materials and demonstrating its potential to prevent karst water inrush disasters.

Abstract

Grouting is the most commonly used method to control water inrush in underground engineering. Traditional cement-based materials are easy to dilute and hard to coagulate under the influence of large flow and high-velocity water inrush. To address these deficiencies, a new type of polymer grouting material with an excellent expansion ratio was synthesised. The material quickly absorbs water and has an expansion ratio of 1:300. The material is composed of a superabsorbent polymer (SAP), glycerol, and ethanol. The effects of water quality on the expansion ratio and expansion rate of the material were examined, and the best solid–liquid ratio for the slurry was determined by fluidity measurements. A karst specially designed pipeline water inrush test device showed that 800 g of SAP can achieve 0.6 m/s water flow blockage in the smooth pipeline, demonstrating that the ability of the SAP slurry to block water inrush is superior to those of other materials. This study provides a reference for water inrush plugging, and has important implications for the reduction and control of karst pipeline-type water inrush disasters, ensuring the safety of construction sites and preventing loss of life and damage to property.