Monitoring of Roof Bolting as an Element of the Project of the Introduction of Roof Bolting in Polish Coal Mines—Case Study

Abstract

Roof bolting is the most popular type of support for underground mines’ workings. However, in Polish coal mines it is used only as a supplementary support. To raise the effectiveness and economic score of horizontal development works, JSW (Jastrzębska Spółka Węglowa) started a project to introduce the independent rock bolting support in its mines. The key element of the project is the monitoring of mine workings supported with roof bolting, as appropriate control allows one to ensure a proper level of safety. The following work presents a monitoring system for mine working supported with roof bolting applied in the project, as well as results of the measurements obtained using this system. The aim of the monitoring was to prove that independent roof bolting provides a proper level of safety and thus is applicable in conditions of Polish underground coal mines, particularly Budryk mine. It was to be proved by the evaluation of data obtained from instrumented bolts, extensometers of different type and convergence measurements. These results allowed us to verify the validity and reliability of the roof bolting in geological and mining conditions of Silesian Coal Basin.

Assessment of the Impact of Working Risks in the Exploitation of Raw Materials

“…The investigated mining company is engaged in the extraction of raw materials and operates in Slovakia, where the mining and processing activities of the company are distributed in several regions. In addition to product quality, it also takes into account the environmental aspects of mining, the production and processing of raw materials, as well as the friendly approach to nature and the environment in all places [24]. The Risk matrix (matrix of consequences and probabilities) shows the relationship between the estimated consequences and probability, while its objective is to express the level of risk or to determine its classification.…”

Influence of Stress Disturbance on the Deformation of Nearby Cemented Roadways following the Excavation of Chambers

“…Roadways built with weakly cemented material are typically vulnerable to significant issues like rapid decrease in anchoring force, substantial deformation of the neighboring rock, and a brief self-stabilization period. Although the traditional active support methods such as anchor bolt, anchor cable, and combined support with an anchor cable net can effectively control the deformation of the surrounding rock of coal roadways, such methods cannot limit the deformation of the surrounding rock of soft rock roadways and cannot meet the requirements of the support of soft rock roadways under the current coal mining conditions, and the stability of the roadway is difficult to be guaranteed [5][6][7][8][9].…”

Influence of Base-Angle Bolt Support Parameters and Different Sections on Overall Stability of a Roadway under a Deeply Buried High Stress Environment Based on Numerical Simulation

“…Moreover, Krykovskyi et al [14] carried out research on the strengthening effect of grouting the rock bolt onto weak surrounding rock, which enriched the strengthening theory of bolt support. Dyczko et al [15] verified the importance of the roof bolt and applied it to engineering practice to carry out relevant monitoring. Małkowski et al [16] evaluated the stability of the roadway using five different techniques and continuous monitoring for six years, based on the premise of large-scale rock mass and support monitoring.…”