SCIENCE AND PRACTICE FOR ASSESSING THE STATE OF UNDERGROUND STRUCTURES SUPPORT BY VIBROACOUSTIC METHOD

In this work, subject of the research is a method of non-destructive vibroacoustic control of underground structures support. The purpose of the research was to create a methodology and apparatus for vibroacoustic control of the state of the system "support – rock massif" with a wide range of use. The main types of objects where the use of this method is appropriate are determined. Negative influence of external factors on performance characteristics of support is shown. A basic type of support for underground objects is reinforced concrete. It is established that the most characteristic defects are formation of cavities in geological environment behind the support and broken connection of separate segments of the support. The influence of these defects on character of free oscillations of support elements at single shock action was studied theoretically. It is established that the following parameters can be informative for detecting these defects: amplitude characteristic of package of vibration, its duration and spectral composition. Information about the means of vibroacoustic control designed by the Institute with participation of the authors is provided. The methodical features of using vibroacoustic control for assessing technical state of different types of support are considered. The limitations for using the method are explained. Some results of the use of vibroacoustic control of support in underground objects of the various purposes are given.