STATIC-DYNAMIC LOOSENING OF FROZEN ROCKS

Abstract

Loosening of frozen rocks and soils is one of the most complex, labor-intensive and economically costly technological processes in mining, energy and military complexes, construction of roads and industrial facilities, laying of canals,melioration and other industries. Of all rippers having mechanical means of destroying frozen rocks and soils, hydropneumatic percussion instruments are preferred. They destroy frozen rocks and soils at high dynamic loads. Hydropneumatic shock mechanisms are characterized by high specific energy, autonomy of supply, compactness, simplicity of construction and control in work. Rippers with combined methods for the destruction of frozen rocks and soils are increasingly used.This article presents the results of practical research on the loosening of frozen rocks and soils. The dependences of the change in the velocity of the antiphase ripper on the hydropneumatic hammer, the energy and frequency of the hammer blows are established.Selected and substantiated operating parameters of the active ripper with anti-phase working active device. Industrial tests have confirmed that the optimal mode of active loosening of frozen rock with a frequency of shocks C = 100… 110 is the mode with an average speed of movement of the base machine 0.88 m/s and activation of the tooth with energy of 7.5 kJ with a frequency of 2.0 Hz. The optimality of this mode is confirmed by the minimum specific energy consumption of 1282 kJ/m3, and with productivity of 0.175 m3/s. Field trials of the active ripper were conducted in winter at a special polygon of Gorenichi village, Kyiv region. The freezing of the soil reached 1.1 m. The effect of loosening depth on the loosening rate of the active loosening was studied with the traction power of the base machine at 0.16 and 0.24 MN. Active loosening was carried out at the coupling coefficient of the main machine with a surface of 0.4 and 0.6, respectively. Changing the speed with increasing depth of the loosening is nonlinear. With increasing depth from 0.4 to 0.5 m, the loosening speed decreases by 1.83, 1.72, and 174 times with the impact energy of 6.0, 7.0, and 8.0 kJ, respectively. As the loosening depth increases from 0.5 to 0.6 m, the intensity of the speed reduction decreases. In this case, the speed is reduced respectively by 1.52, 1.45 and 1.74 times. Increasing the loosening depth from 0.6 to 0.7 m leads to a decrease in the loosening rate by 1.29, 1.23 and 1.56 times, respectively.ly.