THE STUDY OF DYNAMICS OF DEVELOPMENT OF DEFORMATION PROCESSES AND CRACK FORMATION IN THE ROCK MASSIF AROUND THE WORKING WHICH IS SUPPORTED UNDER A LONGWALL.

Purpose. Study of dynamics of development of deformation processes and crack formation in the rock massif around the working which is supported under longwall, with different time of putting into operation of protective facilities. Methodology. By means of simulation using equivalent materials we have investigated the rock massif deformation and cracking around the working supported under longwall with different time spent on putting into operation of the protective facilities. Findings. This paper presents a protection method with fast putting into operation of the protective facilities. In laboratory conditions we have obtained a positive effect of the proposed method application. Originality. It was shown that the time spent on putting into operation of the protective facilities has a significant influence on the deformation of the rock massif; place of location and development path of cracks. Growth of the main crack in the roof is caused by its subsidence, and determines the stress on the tunnel and its deformation. We have determined the time and place of localization and development of the main crack, which causes the collapse of main roof console under different time of putting into operation of the protective facilities. Practical value. Use of the proposed protection method with fast putting into operation of the protective facilities eliminates the roof stratification and inrush over the protective facilities into working; creates conditions for the occurrence of the main crack over the protective facilities and its development in the direction of mined-out area. Brokendown rock of the main roof shifts its weight on the immediate roof rocks over the open area of longwall, this also lowers the load on the support and lining of working, which reduces the load on the protective facilities and provides more stable state of working. [ABSTRACT FROM AUTHOR]