Aram Aziz, Mehrdad Ghahremani, Seyed Mohammad Fattahi, Abbas Soroush, Seyed Mohammad Reza Imam

Abstract: Karstification, a natural geological process occurring in soluble rocks such as gypsum and anhydrite, poses significant challenges to engineering structures, especially hydraulic ones, due to water infiltration under high pressure and velocity. Therefore, improving the stability of these rocks in water is crucial. This study investigates the impact of water pressure on accelerating dissolution and karstification in soluble rocks. Additionally, it explores methods to control karstification through the application of chemical grouting. The gypsum samples were collected from the Fatha Formation near the Mosul Dam. To simulate karstification, an axial hole was created in the center of gypsum samples, which were then exposed to hydraulic shear stress under various pressure conditions. To mitigate the karstification, two commercially available chemical grouts including polyurethane (PU) and a mixture of acrylic and cement (ARC) were applied to coat the soluble rocks. The study included experiments on both untreated and chemically coated (grouted) samples. The results demonstrated that gypsum solubility increased with rising water pressure, while both PU and ARC successfully inhibited further dissolution of the gypsum rock during the experiment.

Keywords: Gypsum, dissolution, karstification, chemical improvement, Mosul dam, water pressure.

Date Published: February 4, 2025
DOI: 10.11159/ijci.2025.002

View Article