Numerical Analysis of Roadway Rock-Burst Hazard under Superposed Dynamic and Static Loads

Abstract

Microseismic events commonly occur during the excavation of long wall panels and often cause rock-burst accidents when the roadway is influenced by dynamic loads. In this paper, the Fast Lagrangian Analysis of Continua in 3-Dimensions (FLAC3D) software is used to study the deformation and rock-burst potential of roadways under different dynamic and static loads. The results show that the larger the dynamic load is, the greater the increase in the deformation of the roadway under the same static loading conditions. A roadway under a high static load is more susceptible to deformation and instability when affected by dynamic loads. Under different static loading conditions, the dynamic responses of the roadway abutment stress distribution are different. When the roadway is shallow buried and the dynamic load is small, the stress and elastic energy density of the coal body in the area of the peak abutment stress after the dynamic load are greater than the static calculations. The dynamic load provides energy storage for the coal body in the area of the peak abutment stress. When the roadway is deep, a small dynamic load can still cause the stress in the coal body and the elastic energy density to decrease in the area of the peak abutment stress, and a rock-burst is more likely to occur in a deep mine roadway with a combination of a high static load and a weak dynamic load. When the dynamic load is large, the peak abutment stress decreases greatly after the dynamic loading, and under the same dynamic loading conditions, the greater the depth the roadway is, the greater the elastic energy released by the dynamic load. Control measures are discussed for different dynamic and static load sources of rock-burst accidents. The results provide a reference for the control of rock-burst disasters under dynamic loads.

Mechanism of Rock Burst Revealed by Numerical Simulation and Energy Calculation

“…When rock burst occurs, the energy that causes huge damage to roadway and surrounding rock mass is mainly elastic wave energy [36]. In our method, all the released elastic energies will be converted into various forms of energy, such as dissipation energy, kinetic energy, and friction heat energy, only a part of which will convert into elastic wave energy, so we assume an energy conversion factor (β) of elastic wave.…”

Characteristics of Valuable Microseismic Events in Heading Face of an Underground Coal Mine Using Microseismic System

“…For working face, two kinds of events all occur, energy and location of roof breaking events can reflect the roof damage situation [40], and quantity and energy of coal fracture event can reflect the situation of advanced abutment pressure [41]. While for heading face, most of the MS events are coal fracture events, the larger the fracture scale is, the greater the energy is [42], and the events can be divided into two categories according to the fracture scale: AE events with small energy, which are caused by a small amount of coal fractures, and MS events with large energy, which are caused by a large scale of coal fractures and usually accompanied by loud sounds [43], but in fact, there is no strict quantitative distinction between AE events and MS events (at least in the present study, no exact answer has been found). AE events are considered to be related to rock burst risk, which has been verified at many laboratory tests [44,45] and field achievements [46], and the AE events in the laboratory are completely different from those in the field (the difference between the two may be hundreds of times).…”

Designing A New Suitable Support System for Deep Virgin Coal Mining Blocks of Godavari Valley Coalfield

“…Numerical studies help to analyze the mere cause [5]. Basalt ow and faults has also been reported from Pench area (Western Coal eld Ltd), and it has been found that high horizontal Stress affects the stability of development galleries at Thesgora mines [13].…”