Types and prevention measures of mine geological disasters

1. Overview

Because the mineral mining process is bound to change the original stable mineral conditions, change the local geological environment, and the disaster caused or induced by man-made mining activities to change the geological environment is called mine geological disaster. The occurrence of mine geological disasters will cause inestimable harm and destruction to ecological environment, natural resources and economy and society. China's mineral mining has a long history, in a long period of time, China's mineral mining technology and equipment are relatively backward, under this condition of mineral mining leads to the deterioration of mining geological environment, mining geological disasters frequently. Life-threatening mining accidents and environmental disasters occur from time to time, and there is a gradual upward trend in recent years. Therefore, according to the occurrence and development laws and characteristics of mine geological disasters in China, it is a very necessary work to classify mine geological disasters in detail and put forward measures to prevent and control disasters according to their respective characteristics.

2. Types of mine geological disasters

As far as the current state of scientific and technological development is concerned, the scope of mining activities is still mostly limited to the Earth's surface and the interior of the rock sphere. Before lode mining, the geological environment of the mining area is in a stable equilibrium state. In the mining process, a large amount of earth and rock is dug out from the soil and rock circles inside the crust, which greatly destroys the geological environment and makes it in an unstable state. We can see that no matter drilling and mining, pit mining, liquid injection mining, or open pit mining, all have changed the original geological environment, and this imbalance has led to the instability of the crust material, which is easy to cause catastrophic geological changes.

There are many types of mine geological disasters, which can be divided into abrupt mine geological disasters, such as mine water inrush, gas explosion, rock explosion, etc., if only from the rate of occurrence of disasters, the other is slow type mine geological disasters, such as ground subsidence of goaf, water pollution and so on. However, the most commonly used classification of geological hazards is usually based on the spatial and temporal distribution and genetic relationship of geological hazards. This classification method is conducive to the in-depth investigation of the causes of geological disasters, so that appropriate prevention and control measures can be formulated according to various types of geological disasters. The geological hazards induced by unreasonable or unscientific change of geological environment in the process of man-made geological processes basically cover all types of geological hazards except volcanic eruptions.

2.1 Deformation disaster of rock and soil layer

This part of mine geological disaster is due to the mining activities change the geological environment of the mining area, resulting in the deformation of underground and surface rock and soil layers, and then lead to disastrous consequences.

2.1.1 Induced earthquake

The structural unbalance of rock and soil layer caused by mining activities is reflected in earthquake and fault dislocation. A short time of severe fault dislocation is easy to produce induced earthquake. The shallow earthquake induced by man-made geological change has a small depth, but the harm and destructive power are very great. Small magnitude earthquakes may cause drastic changes in underground and surface rock and soil layers, thus causing harm to buildings and surface structures.

2.1.2 Fault dislocation

Fault dislocation is also a manifestation of the structural imbalance of the circle, but because of the delayed occurrence of fault dislocation, the energy is slowly accumulated, and it is not easy to be measured and detected in a short time. However, it can be predicted that with the continuous development of mining activities, the energy accumulated in the fault will be released in a short time after the mining vein is emptied, which will eventually cause great harm, and this disaster will also have a huge destructive force on the mine and the surrounding geological environment.

2.1.3 Ground layer deformation

The deformation of underground rock and soil layer often leads to the subsidence, settlement and cracking of surface rock and soil layer, which leads to the geological disaster of mine with great harm. For example, mine floor and goaf collapse, mining ground subsidence, ground cracking. The common ground collapse in mining area mainly occurs in the mining area of shaft mining. The lode burial is shallow, the ground of the mining area is gentle, and the phenomenon of ground collapse and settlement is relatively common. In mining areas where mineral veins are buried deep and far from the surface, large-scale collapse may occur if slag cannot be backfilled in time. Ground collapse, settlement and cracking may not only damage soil, water and buildings, but also destroy public resources and buildings such as roads and reservoirs, causing greater harm.