Study on Monitoring Rock Burst through Drill Pipe Torque

Abstract

This paper presents a new method to identify the danger of rock burst from the response of drill pipe torque during drilling process to overcome many defects of the conventional volume of drilled coal rubble method. It is based on the relationship of rock burst with coal stress and coal strength. Through theoretic analysis, the change mechanism of drill pipe torque and the relationship of drill pipe torque with coal stress, coal strength, and drilling speed are investigated. In light of the analysis, a new device for testing drill pipe torque is developed and a series of experiments is performed under different conditions; the results show that drill pipe torque linearly increases with the increase of coal stress and coal strength; the faster the drilling speed, the larger the drill pipe torque, and vice versa. When monitoring rock burst by drill pipe torque method, the index of rock burst is regarded as a function in which coal stress index and coal strength index are principal variables. The results are important for the forecast of rock burst in coal mine. Drill Pipe Torque AnalysisWhen drilling in coal seam by electric-drill and twist drill pipe, the torque on drill pipe is mainly acted by electric-drill

Study on the Relationship between Stress and Charge of Coal Mass under Uniaxial Compression

“…en, the probability of the number of charge events in the process of deformation and failure of coal and rock mass can be expressed by formula (1). At the same time, it is assumed that the microelement cannot recover its strength once it is broken.…”

“…Nowadays, the threat of rock burst is increasingly intensifying with the increase of mining depth and intensity. As a result, research on the prediction of rock burst is extremely urgent [1,2]. e occurrence of rock burst is a result of multiple factors, including geostress, mining depth, coal-rock impact tendency, geological structures, overlying strata structure, and mining layout.…”

Mechanical Properties and Control Rockburst Mechanism of Coal and Rock Mass with Bursting Liability in Deep Mining

“…In terms of the prevention and control of rockburst, the methods of mining the liberating seam, large-diameter borehole pressure relief of coal seam, water injection of the coal seam, and deep hole blasting of the roof are often used to reduce or eliminate the risk of rockburst [22][23][24][25][26]. For the effect of prevention measures, the drilling cutting method is generally used for verification [27,28].…”

GA-Based Early Warning Method for Rock Burst with Microseismic and Acoustic Emission in Steeply Inclined Coal Seam

“…At present, the monitoring and early warning methods for rock burst are mainly divided into two categories: traditional rock mechanics methods (e.g., drilling cutting method, coal and rock mass stress measurement, and core discing method) [16][17][18][19][20][21] and geophysical methods (e.g., electromagnetic radiation (EMR), microseismic (MS), and acoustic emissions (AE)) [11,[22][23][24][25][26][27]. In recent years, geophysics method has been widely used in underground because of its advantages of noncontact, data continuity, and automatic monitoring.…”