Roof collapse in a retained top coal roadway induced by high-energy seismic events: implications from a case study.

Fully mechanized top-coal caving inevitably results in a certain thickness of retained coal above the roadway, which compromises roof stability and increases the difficulty of roof management. This study presents a dynamic disaster phenomenon in the Binchang mining area of China, where high-energy seismic events (HESEs) induced roof collapse in roadways with retained top coal. Disaster characteristic analysis indicates that in high-stress zones, the support system in roadways with retained top coal gradually deteriorates under mining-induced stress loading, and HESEs lead to roof support failure and roof collapse.

Risk assessment and mechanism of rock burst for deep soft coal roadways.

The occurrence of rock burst is related to the physical properties of coal-bearing strata. Under the same mining conditions, the excavation of soft coal seams at 1000 m or deeper has a lower risk of rock burst. The characteristics of rock burst in soft coal seams include a small impact influence range, large roadway deformation, and serious damage to roadway supporting components.

Experimental Study on Calibration of Amplitude-Frequency Measurement Deviation for Microseismic Sensors in Coal Mines.

Microseismic monitoring systems (MMS) have become increasingly crucial in detecting tremors in coal mining. Microseismic sensors (MS), integral components of MMS, profoundly influence positioning accuracy and energy calculations. Hence, calibrating these sensors holds immense importance.

Slip instability behavior of block rock masses on dynamic-static combined loads.

A rock mass is a system of various scale blocks embodied into one another. Inter-block layers are usually composed of weaker and fissured rocks. On the action of dynamic-static loads, it can induce slip instability between blocks.

Evaluation of Anti-Burst Performance in Mining Roadway Support System.

The hazardous effect of a mine earthquake on a roadway is not only related to its energy scale but also to its distance from the roadway. In this study, a signal attenuation model and a disaster-causing model were established to evaluate the mine earthquake effects based on peak particle velocity (PPV) data recorded for 37221-1 upper roadway of the Dongxia Coal Mine, China. The characteristic of dynamic loads due to mine earthquake propagation to roadway surfaces was researched, and critical PPV values were identified using FLAC numerical simulation, which can be used to evaluate the roadway anti-burst performance under the existing support system.

Experimental Study on the Mechanical Behavior of Coal Samples during Water Saturation.

When mining-induced fractures reach overlying aquifers, water enters the mining area and the coal is under different natural water saturation conditions, which significantly affect the mechanical behavior of the coal. In this study, uniaxial compression tests were conducted on dry, partially saturated, quasi-saturated, and fully saturated coal samples. The mechanical parameters, acoustic emission (AE) activities, and failure patterns of differently saturated coal samples were analyzed.

Investigation of coal and gas outburst risk by microseismic monitoring.

In order to improve the monitoring and prediction of coal and gas outburst, this paper proposes a new method for dynamic regional prediction of coal and gas outburst using microseismic (MS) monitoring. The theoretical basis of this method is presented. An index evaluation system was established and applied, based on which field tests were carried out in a coal mine.