Mechanism Analysis of Delayed Water Inrush from Karst Collapse Column during Roadway Excavation Based on Seepage Transition Theory: A Case Study in PanEr Coal Mine

Abstract

Water inrush disaster is one of the major disasters affecting the production safety of coal mines following roof caving, fire, gas outburst, and dust explosion disasters. It is urgent to reveal the water inrush mechanism and take effective measures to prevent the disasters. More than 80% of water inrush accidents occur around geological structural zones such as faults and karst collapse columns (KCCs). The water inrush events from KCCs caused huge economic losses and heavy casualties, and the water inrush process often shows certain hysteresis characteristics. Taking the water inrush disaster from a KCC during roadway excavation in PanEr Coal Mine of Huainan Mining Area as the case study, the delayed inrush mechanism of KCC was analyzed from the aspects of floor failure, KCC activation, seepage transition, and water inrush development characteristics. The results show that the rock mechanical properties and the excavation depth are the main factors affecting the floor failure characteristics. The seepage transformation from pore flow to fracture flow and pipeline flow, with the change in internal composition structure, is the internal mechanism of the delayed water inrush from KCC. The research is of great significance for the prediction and prevention of water inrush disasters from KCCs.

Numerical Simulation of Karst Collapse in Qingling Town, Wuhan

“…With changes in groundwater level, compaction rebound of earth pressure value occurs. Several rounds later, plastic deformation of soil occurs and then develops to cause karst collapse [8] .…”

“…With changes in groundwater level, compaction rebound of earth pressure value occurs. Several rounds later, plastic deformation of soil occurs and then develops to cause karst collapse[8] .The vertical deformation of the soil is directly related to the increase in groundwater. The settlement and rebound of the soil are consistent with the flow field of each layer.…”

Mechanical Response Law and Parameter Influence Analysis of Karst Tunnel Dynamic Excavation

“…The situation of karst collapse is complex and diverse, and the geological hazards caused by karst collapse are universal [5][6][7][8]. It threatens people's lives and property safety and causes significant economic loss, but also brings a lot of construction and operational problems for engineering construction [9,10]. Karst collapse is difficult to predict because of the complex causes of collapse and the following characteristics: territoriality, hiddenness, suddenness and mass occurrence [11].…”

Characteristics and Connectivity Analysis of Hidden Karst in Jurong Pumped Storage Power Station Area, China

“…A phased approach involving field surveys, historical mapping, geophysical investigations, and hydrogeological condition analysis is necessary for identifying, investigating, predicting, and reducing sinkhole hazards in karst areas [2]. The existence of karst leads to many problems of water inflow, leakage, and geological disasters [3][4][5]. Among them, reservoir leakage is the most common problem of reservoirs in karst areas.…”