Inhibition of Karstification Progressing In Soluble Rocks under Water Pressure Using Chemical Grouts

Karstification is considered a common geologic phenomenon in soluble rocks (gypsum/anhydrite) that poses a vast challenge to engineering structures, especially hydraulic structures, due to water seepage with high pressure and velocity under this type of structure.Hence, improving the soluble rocks in the presence of water is imperative.In this study, the dissolution behavior of gypsum rock and the improvement of its solubility have been investigated.To perform this, karstification (gypsum rock dissolution) was simulated by creating a hole in the center of the gypsum samples and subjecting them to hydraulic shear stress under different head pressures.Additionally, to control the karstification of soluble rocks two commercially available liquid polymers, polyurethane (PU) and a mixture of acrylic and cement (ARC) were used to treat the soluble rocks.The rock samples extracted from Fatha Formation outcrop at vicinity of Mosul Dam site.Two sets of experiments were conducted on untreated and chemical grout-treated samples.The obtained findings reveal that the solubility of gypsum increases with the increase in water pressure, and (PU) and (ARC) are the influential chemical grouts in halting the solubility of the gypsum rock samples during the experimental duration.