Setting of the work environment of workers at mining enterprises during thin coal seams extraction influence on the character and the rate of their aging by determination of the biological age and estimation of the occupational diseases development risk value.Methods. The hygienic estimation of the work environment and the occupational diseases development risk value have been determined according to known standard techniques. The approach developed at the Institute of Herontology of National Academy of Medical Sciences of Ukraine has been used for determination of the miners biological age. The aggregate dust load in the air of mining developments has been determined by "АЕRА" respirator. The following equipment has been used for estimation of the human functional state: "Nissei DS-1902" and "Omron M10-IT" tonometers, "Maniquick MQ-160" infrared contactless thermometer, "VМ-150" medical balance. Sampling in the miners breathing zone has been made by "АFА-20" analytical filters. The research results processing has been fulfilled by the method of statistical analysis.Findings. The exceeding of the maximum permissible rates of adverse factors for miners, such as dust, noise and vibration has been set. The work environment is featured by the constant uncomfortable position of miners bodies and the sufficient loading level. It is determined, that the maximum risk of occupational diseases development is connected with the dust and the static loading factors. The work in such conditions leads to rising of the miners aging rate. Thus, the aging rate is equal to 7 years while having 28.3 years of average age for less than 10 years of service length, and correspondingly 9 years for more than 10 years of service length. The exceeding of the biological age on the calendar age is 15 years in average after the shift.Originality. The character of interrelation between the complex of harmful factors, the occupational diseases development risk and the workers aging rates has been set in the conditions of thin coal seams extraction. Practical implications.It is necessary to change the working and recreation modes of miners and to guarantee the work for not more than 4 hours with obligatory breaks for rest, in order to enhance the life time of the miners occupied at coal-face works on the thin coal seams extraction.
The objective of this work is to substantiate the hereditary character of the stresses and deformations accumulation in loose mined rock during the disintegrators working surfaces convergence. It is shown, in particular, that the layer porosity after compression and the side thrust coefficient depend not only on the applied pressure, but also on the initial porosity. It is substantiated the mechanism of interrelation between the stresses and deformations of a layer. The experimental researches on fine– grained granite compression in a rigid matrix have been fulfilled. The approximation of obtained results by polynomial functions has been carried out. The coefficients have been determined by the least-square method. The close agreement of the analytical and the experimental values has been recorded. The initial porosity parameter was put into the equation of dependences of the current porosity and the side thrust coefficient on pressure. The mechanism of the forces distribution on separate particles contacts has been explained in terms of the material compacting hystory. The practical value of the research is in calculating the disintegrators operating parts parameters with account of the mined rock layer condition prior to the act of crushing.
The aim of the work is modelling of stressed condition of the loose mined rock thin layer between two parallel working plates of disintegrator, taking into consideration the dependences of the layer porosity and its side thrust coefficient on the main stress value with hereditary model of deformation accumulation. The equation of extreme balance of mined rock compactable thin layer is obtained for the case of its compression with partial sliding on working surfaces. It is shown, that there is no sliding in the central area of deformed zone, unlike the peripheral area. The iterative algorithm for parameters calculation of the layer stressed condition for the hypothesis of symmetric parabolic distribution of the axial normal stresses in the directions being perpendicular to the plates is developed. The distributions of the side thrust coefficient in the layer, the effective coefficient of external friction and the stresses of disintegrators working surfaces are grounded. The practical value of the research is the possibility to determine precisely the contact forces while crushing of fine-grained material taking into consideration its compactibility.
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