Analysis of aWater-Inrush Disaster Caused by Coal Seam Subsidence Karst Collapse Column under the Action of Multi-Field Coupling in Taoyuan Coal Mine

Abstract

Minin-induced water inrush from a con ned aquifer due to subsided oor karst collapse column (SKCC) is a type of serious disaster in the underground coal extraction. Karst collapse column (KCC) developed in a con ned aquifer occurs widely throughout northern China. A water inrush disaster from SKCC occurred in Taoyuan coal mine on February 3, 2013. In order to analyze the e ect of the KCC in uence zone's (KCCIZ) width and the entry driving distance of the water inrush through the fractured channels of the SKCC, the stress, seepage, and impact dynamics coupling equations were used to model the seepage rule, and a numerical FLAC3D model was created to determine the plastic zones, the vertical displacement development of the rock mass surrounding the entry driving working face (EDWF), and the seepage vector and water in ow development of the seepage eld. The hysteretic mechanism of water inrush due to SKCC in Taoyuan coal mine was investigated. The results indicate that a water inrush disaster will occur when the width of the KCCIZ exceeds 16 m under a driving, which leads to the aquifer connecting with the fractured zones of the entry oor. Hysteretic water inrush disasters are related to the stress release rate of the surrounding rocks under the entry driving. When the entry driving exceeds about 10 m from the water inrush point, the stress release rate reaches about 100%, and a water inrush disaster occurs.

A Behavior Change Mining Method Based on Complete Logs with Hidden Transitions and Their Applications in Disaster Chain Risk Analysis

“…Similarly, the calculation rules and determination method in Algorithm 1 can be used to calculate exclusive and coupled disaster chains. However, it should be noted that for coupled disaster chains, the cause is the coupling of multiple disasters, and their risks and damage degree are thus higher [27]. This paper mainly introduces the method of change mining using log behavioral profile relations and does not discuss how to conduct risk assessment research for a coupled disaster chain or how to transform strong coupling into weak coupling or zero coupling, which are topics to be explored in further research.…”

A state-of-the-art review on rock seepage mechanism of water inrush disaster in coal mines

“…The effectiveness of the proposed method is verified by ultra-high precision micro-seismic monitoring, and the method can directly reflect the connectivity of the water-conducting pathway. By establishing a FLAC 3D numerical model, Lin et al (2021) obtained the evolution law of the plastic zone and the seepage field, and used the affected width of KCP as a criterion of water inrush, that is, if the width reaches a critical value, the aquifer is connected with the floor fracture zone, and then water inrush can be caused.…”

Analysis of the Influence of Groundwater Level Fluctuation on Karst Soil Cave Collapse

“…Wang et al improved the mechanical model of soil cave collapse based on the ultimate balance theory and accurately divided the evolution stages of soil caves [4][5][6]; Guo et al established a ground subsidence mechanical model of covered karst soil caves considering the cave's shape and size under the condition of groundwater slump to reveal the internal relationship between the initial groundwater level, the shape and size of the cave, and the negative pressure of the soil cave cavity and clarified the influence of the negative pressure change caused by the water level drop on the stability of the soil cave evolution stage [7,8]; Xue et al conducted acoustic emission tests to measure the effect of CO 2 adsorption force on the mechanical properties of deep coal seams and established an elastic damage constitutive model of nonlinear stress-strain relationship and proposed the deformation and failure mechanism of deep coal seam due to the strength of gas adsorption force [9]. To the greatest extent, the field test can reflect the collapse process of karst soil caves under hydrodynamic conditions [10]. Chen et al carried out field pumping tests and clarified that the water level change caused by pumping is the main factor of collapse [11]; Jiang et al and Jia et al conducted long-term monitorization and analysis of the groundwater level change on site and revealed the formation mechanism of the soil cave collapse and the response of the deformation to the water level change [12,13].…”