The geological environment of mine is deteriorating constantly, and disasters and accidents occur frequently

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. According to the occurrence and development laws and characteristics of mine geological disasters in China, it is particularly important to classify mine geological disasters in detail and put forward the measures to prevent and control them according to their respective characteristics.

1. Types of mine geological disasters

At present, mining activities are still mostly confined to the Earth's surface and inside the lithosphere. 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.

Whether drilling mining, excavation mining, liquid injection mining, or open pit mining, all change the original geological environment, the appearance of this imbalance leads to the instability of the crust material, and then easily lead to 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.

The most commonly used classification of geological disasters is usually based on the spatial and temporal distribution and genetic relationship of geological disasters. 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 disasters induced by unreasonable or unscientific change of geological environment in the process of man-made geological processes basically cover all types of geological disasters except volcanic eruptions.

1. Formation disaster of rock and soil layer

Some mining geological disasters are caused by the mining activities changing the geological environment of the mining area, leading to the deformation of underground and surface rock and soil layers, and then leading to disastrous consequences.

2. 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.

3. 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.

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 cause great harm, and this disaster will also have great destructive power to the mine and the surrounding geological environment.

4. Ground circle 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, if slag cannot be backfilled in time, large-scale collapse, ground collapse, settlement and cracking may occur, which not only damages soil, water and buildings, but also damages public resources and buildings such as roads and reservoirs, causing greater harm.

5, slope rock mass movement

This kind of disaster is caused by the unstable structure of geological slope or surface fault edge in mining area, such as collapse, landslide, debris flow and so on. For example, the instability of mining slope often causes disasters such as rock and soil landslide, rock fall and so on, and the soil slope forms fluid soil after rain, forming disastrous debris flow and so on.

Unstable structures are formed due to unreasonable mining and stripping disorders and steep slope angles. This type of mine geological disasters mostly occur in open-pit mining or excavation mining mines.

Such disasters often occur instantaneously, but the results are more harmful, such as mine landslides, often destroy the minerals, resulting in a large number of casualties, great harm.

6. Mine engineering disaster

Irrational mining means and off-hand mining methods often lead to underground engineering disasters, such as cave-in, roof fall, sideway, bottom heave, rock burst and so on.

These disasters are due to the crustal stress changes in the rock and soil layer in the mine and mine, resulting in the sudden release of rock and soil stress, resulting in a large number of rocks and debris, and sudden advance into the mine, which brings harm to the mine mining, endangers the safety of miners and causes property losses.

For example, rock burst in the pit is because the surrounding and top and bottom wall rocks of the mine are subjected to huge rock ring stress. Once the mining surface cannot maintain balance, the rock ring stress may be suddenly released, resulting in rock rupture and burst, and a large number of jets and explosions into the pit, thus bringing devastating disasters to the mine.

7. Water table variation disaster

In the process of mining, deep mining sometimes destroys the structural stability of groundwater free shallow water layer or laminated aquifer, and then causes the change of groundwater level and mine geological environment, resulting in disastrous consequences.

8, the mine water gushing water

Water inrush and water gushing are one of the most common mine disasters. Due to the rapid change of the water table in a short time, the mine suddenly flooded. This kind of mine geological disaster is sudden and large scale, resulting in very serious consequences.

In the mining process, due to the insufficient estimation of the discharge rate of the inflow of water in the mine, the mining process often penetrates the water-separating fault, or suddenly encounters the water storage cave and underground river, resulting in a large influx of groundwater, resulting in the flood of pits and Wells, resulting in casualties or other serious catastrophic consequences.

Sand gushing in the pit is the associated disaster of water inrush in the mine. When the aquifer or karst cave rich in sediment is encountered in the mining process, the water barrier layer is broken, and the sediment and rock debris rush into the mine together with the water, resulting in slurry gushing disaster.

Other permeable faults and wet beds often leak into the pit because of the dislocation of the fault and the inclusion of sediment. The result is that the mine is blocked by mud, and the equipment and mining personnel are buried by sand, resulting in disastrous consequences for the mine.

9. Disaster of tail warehouse and field warehouse

The mining of many mines is accompanied by the existence of mines and tailings ponds. The instability of the reservoir is mainly due to the huge damage caused by the debris flow after the tailings dam can not withstand the pressure.

The dam break of tailing reservoir often occurs because of the increasing pressure on the stability of the dam body, or because of the overflow of waste ore liquid and the dam body piping. Tailings break the levee brings immeasurable disastrous consequences to the production and life of the people in the mining area, but also causes pollution and long-term harm to the local soil and water environment.

Second, mine geological disaster prevention measures

Due to the characteristics of time and space and the occurrence conditions of geological disasters in mines, with the gradual application of geological exploration means in mines, effective prevention and control measures should be taken according to different environments to prevent or monitor and warn the occurrence of geological disasters in mines and reduce casualties and property losses.

(1) Establish and improve pre-mining risk assessment and environmental assessment, and formulate policies, regulations and planning systems for environmental protection and restoration management. Strict evaluation before mining.

(2) Strengthen publicity, popularize the knowledge of mine geological disaster prevention and control, improve the quality of mining personnel, and enhance their sense of crisis and alertness to geological disasters. Improve the skills and means of disaster prevention and mitigation of all personnel in the process of mine production, and strengthen the training of mine geological disaster prevention, avoidance and rescue.

(3) Apply advanced information and geophysical exploration means to closely monitor mine geology, implement real-time monitoring and dynamic monitoring of potential disasters that may occur, establish a mine geological disaster monitoring system, realize a dynamic tracking and management system of mine geology and environmental ecology, and avoid major personnel and property losses.

(4) Strengthen the design of mine and mine slope, conduct slope monitoring, strengthen the retaining wall to stabilize the geological structure of the slope, if there is cracking and deformation after excavation, timely geological investigation, and take preventive measures. Reasonable construction of tailings dam, the formation of a stable mine and tailings reservoir, reduce the risk of landslide and collapse.

The remote sensing set "3S" technology is used to grasp the possible distribution, occurrence location and region of geological disasters in time. The global positioning System is used to accurately locate the high-risk points of geological disasters, and the superposition analysis is carried out by remote sensing satellites to predict the trend of disasters.

Iii. Mine/mining area safety monitoring and early warning system

Zhongke Chuanxin conducts in-depth research in the monitoring fields of open-pit slope monitoring, tailings pond safety monitoring, goaf surface settlement monitoring and other monitoring fields. It uses sensor technology, signal transmission technology, network technology and software technology to monitor various key technical indicators of mine safety, record data, analyze trends, assist the decision-making of competent units, and comprehensively improve the level of safety supervision of mining enterprises. Strengthen the early warning and response capacity of enterprises, society and government.

1. Function of mine/mining area safety monitoring and early warning system

(1) Realize comprehensive, all-weather real-time automatic monitoring of each monitoring point, and grasp the safety status of the overall operation of the monitoring body in real time.

(2) Hierarchical early warning and forecasting, when there is an emergency abnormal situation, the system can timely send alarm information by SMS or platform interface, real-time comprehensive warning function.

(3) Realize basic data management and historical data storage, and provide simple, clear, intuitive and effective reference information for the safety production management of mining enterprises.

(4) Realize data interconnection with relevant departments, meet the rights management function, and realize the sharing of mining safety monitoring information at the city, county and mine levels.

2. Application of mine safety monitoring and early warning system

01 Tailings pond safety monitoring

The tailings pond safety monitoring system is a system in which automatic monitoring equipment, power supply, communication, lightning protection and other facilities are arranged on the tailings pond reservoir area, tailings dam, flood discharge facilities and other structures. Through intelligent sensor automatic measurement, video surveillance, network communication and computer technology, the tailings pond safety can be automatically monitored, monitored, analyzed and warned all weather.

02 Surface mine slope safety monitoring

The open-pit slope safety monitoring system can help enterprises and safety supervision departments quickly grasp the latest trends of mine safety technical indicators; Help inspection personnel to grasp the condition and safety status of unstable slope of open pit in time; It is helpful for the safety supervision department to quickly capture the characteristic information of the unstable region in this area, and provide reliable data and scientific basis for the correct analysis, evaluation, prediction, forecast and treatment of the unstable region of slope. The auxiliary related units set up theoretical models according to the deformation conditions of slope accumulation at different stages.

03 Goaf surface settlement monitoring

The goaf surface settlement monitoring system has the functions of remote data transmission, remote status browsing, remote system setting, data management, user management, safety management, etc. The abnormal data in the monitoring data can be found timely and accurately, the instability of the goaf can be warned, and the relevant management units can make emergency preparations in advance to avoid the loss of personnel and property caused by disasters.