ENGINEERING AND GEOLOGICAL ASSESSMENT OF THE CONDITION OF THE URYTCH ROCKS

Abstract

The article presents a comprehensive engineering and geological description of the Urytch Rocks and evaluates their condition. It has been established that this is an erosional remnant of the deposits of the Yamne region of the early Paleogene, which is under the influence of a wide range of reporting agents, which constantly change its condition and stability, creating certain threats for tourists. According to their lithological composition, the rocks of the Urytch Rocks are represented by gravelites, fine-medium-grained quartz sandstones with an admixture of gravel material, and relatively homogeneous fine- and medium-grained quartz sandstones with almost no impurities. The rock particles are mainly poorly sorted with a medium and low degree of rolling, composed mainly of quartz grains with a minor admixture of glauconite, mica and ore minerals. The rocks are dominated by a specific type of compression cement, which causes a fairly high closed porosity and low water absorption capacity. The density of rocks varies in a fairly wide range from 2,06 to 2,30 g/cm3. The smallest values in terms of absolute value are characteristic of the most brittle rocks, with a decrease in the degree of brittleness, the density increases significantly. The porosity of the studied rocks is quite high – 13–22%. Pores are mostly closed. The average ratio of open and closed pores is 1:3. Water absorption of various lithological differences varies from 4 to 9% and characterizes them as poorly water-absorbing, which may indicate a fairly high resistance of rocks to the influence of physical weathering agents. The strength characteristics of rocks (temporary resistance to uniaxial compression) vary in an extremely wide range from 0,3 to 22,3 MPa. In general, the rocks are characterized by high values of the strength index, which is 10,8 MPa on average. The leading role in the formation of the stability of the rock massif is played by its fissures and the constant increase in the degree of fracture. Based on the set of features, the following genetic types are distinguished here: tectonic cracks; layering and primary separation cracks; cracks in the on-board resistance; weathering cracks. The high degree of impact of the rock massif by the polygenetic system of cracks significantly reduces its stability and requires the adjustment of tourist routes, and the installation of warning signs in the most dangerous places.