Abstract
A method for optimizing the protecting pillars parameters during the study of soft enclosing rocks (in Ukraine mines) is represented. The necessity of a differentiated approach has been substantiated when choosing the protecting pillar parameters based on the geomechanical factors analysis influencing the state of massif. Mining and geological situation was analysed. It has been studied a stress-strain state (SSS) along the protecting pillar width with account of the mined-out space on the basis of a computational experiment and is presented in the form of curves of vertical and horizontal stresses distribution, as well as stresses intensity distribution. The recommended engineering decisions have been substantiated and the SSS of fastening and security structures has been analysed. A certain reserve of the fastening structure loadbearing capacity as part of the frame support and the combined roof-bolting system has been revealed. An evidence base has been created for the measures development on conducting and maintaining mine workings in the zone of the stope works influence. The recommendations have been developed on the protecting pillar formation with a width of at least 40 – 45 m to exclude the stope works influence.
Highlights
IntroductionThere are trends to drive out the hydrocarbons from use in the energy sector
At present, there are trends to drive out the hydrocarbons from use in the energy sector
One of the resource-saving trends in extraction of mineral resources is the optimization of the protecting pillars parameters, in which up to 70% of standard quality coal reserves are concentrated in exploited fields
Summary
There are trends to drive out the hydrocarbons from use in the energy sector. In the lower part of the main roof, weakened sandstone and argillite with a medium thickness will definitely collapse into the mined-out space, and the rock cantilevers, hanging from them, have a small length Both above factors facilitate the formation (at the mined-out space boundary) of the bearing pressure zone with a low stresses concentration, which will decrease when moving backward into a virgin massif in the direction of the NDS of the seam C10l. Both lithotypes are of medium-bedded stratification and their water saturation from the seam C10l is predicted For this reason, an unstable state of border rocks should be expected in the NDS roof to the thickness height of siltstone and argillite. – it is predicted the development of differently vectored rock pressure manifestations on the mine working contour and it is recommended to use various engineering decisions to ensure its stability, in particular, combined roof-bolting systems and the structural coupling of lateral resin-grouted roof bolts with the prop stays of the frame support
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have