Hydraulic factors of piping of fractured sandstone with gypsum cement

摘要

1.Hydraulic factors of the process of piping disintegration of gypsum-cemented sandstone, studied in connection with an evaluation of the seepage strength of the foundation of the Irganai dam on the Avarskoe Koisu River (Dagestan), were examined.2.A schematization of piping processes is presented, on which were based laboratory investigations that made it possible to reveal the effect of self-plugging of fractures in a rock mass having a framework of cemented grains and to establish criterion (based on the condition of no mechanical piping) values of the velocities and gradients of the head of water flowing through the fractures in the mass of such rocks.3.The results of the investigations can be used for a further, more detailed study of processes of hydrochemical decomposition of sedimentary rocks, as well as initial data when evaluating the piping resistance of the foundations of particular structures.