Problems and prevention methods of slope stability in open-pit mines

1 Influence of mining geological disaster factors on mineral resources development China's economic development can not be separated from rich mineral resources. In recent years, China has intensified mining efforts, which destroyed the formation structure to a certain extent and led to geological disasters of different degrees. On the one hand, the formation has a relatively complex structure, on the other hand, the internal structure of the formation will be affected by natural and human factors, which will lead to the instability of the open-pit mine slope.

1.1 Artificial influence The early mining control is not enough, there are many illegal mining enterprises, resulting in serious damage to the formation structure, many mines in our country are affected by human factors such as blind mining uneven settlement, and even lead to slope collapse and other safety accidents, seriously threatening the people's life and property safety.

1.2 Impact of Natural factors The exploitation of mineral resources will not only be affected by human factors, but also by changes in the internal structure of strata. The Earth's crust is in the process of continuous movement, and the collision of some plates will lead to earthquakes, strata collapse and other problems, resulting in the downward diffusion of internal resources, including mine resources, which greatly increases the difficulty of mineral resource development. In addition, the basic structure of the ground surface will also be affected by plate movement within the ground, weakening the support of the surface, and then causing surface landslide, which poses a threat to the safety of operators.

There are many links in the mining process, and many factors will affect the stability of the slope. In order to prevent slope safety problems, it is necessary to summarize and summarize these influencing factors.

This article boils it down to the following points:

2.1 Factors of geological environmental conditions of slope Through the study of slope stability, it can be seen that the characteristics of engineering sites such as strata, geological structure, rock layer and ore body structure will directly affect the stability of slope. Under normal circumstances, there will be changes in mechanical properties, material properties, chemical properties and other characteristics between different mineral layers, which will have different degrees of influence on the stability of the slope, and then reduce the stability of the mine slope, and even cause serious problems such as landslide and collapse.

2.2 Factors of natural conditions Precipitation is the factor that has the greatest influence on the stability of open-pit mine slope. The open-air slope usually does not cover any shelter. When there is rainfall, the slope will penetrate deep into the water content of the soil, which will cause the soil structure to become weak and reduce the stability of the slope. Especially when it is subjected to external forces, it will lead to landslide and other adverse problems.

Factors of staff exploration and resource development In the process of mining resources development, it is necessary for technical personnel to do a good job in the preliminary investigation work, and then relevant workers begin to develop resources, among which the indirect influencing factor is the investigation work. Before the exploitation of mineral resources, the surveyor needs to investigate the geological conditions of the region where the mine is located, do a good job in the analysis and calculation of the survey data, obtain the survey results and submit them to the designer, the designer will carry out the mining plan design according to the survey results. In the investigation stage, if the surveyor has mistakes in the work, the accuracy and validity of the investigation documents may be reduced, and the rationality of the design scheme will be reduced. Similarly, if there are mistakes in the design stage, it will also have a negative impact on the development of mine resources in the later stage, resulting in inconformity between the design document and the actual situation of the mine, resulting in the occurrence of open-pit mine slope landslide and other disasters. The stability of the slope is directly affected by the development of resources. In the development of minerals, there are many work contents such as perforation and blasting. In these work processes, the internal structure of the slope will be directly damaged by vibration, which will lead to the instability of the internal structure and landslide, collapse and other problems.

3. Slope disaster prevention methods

3.1 Introduction of full hydraulic dynamic mining engineering investigation technology In order to ensure the stability of mining slope, it is necessary to select a reasonable investigation method. At present, one of the commonly used mining engineering exploration technologies is full hydraulic dynamic technology. When using this technology to survey, it is necessary to make a reasonable arrangement of the survey site, innovate traditional technology, actively apply modern cloud data technology and big data technology, sort out and analyze the data collected by the survey site, and analyze the occurrence of mineral resources in the mining area according to the material properties of rock mass. In addition, the survey points can be appropriately increased, the accuracy of the collected data can be improved, and the problem of inconsistency between the survey results and the actual situation caused by non-standard survey can be reduced.

3.2 Adjustment of slope bottom drainage system layout in mining area slope stability will be seriously threatened by mining bottom breaking technology. In order to control landslide in mining area, drainage measures need to be fully taken. At present, the detection method of slope bottom drainage in mining area is usually adopted by adjusting slope value by platform. First of all, the slope value of the platform at the bottom of the mine slope should be detected, and then the slope and direction of the drainage system should be rationally designed, and finally the water that passes the bottom of the stope slope should be discharged.

3.3 Strengthening the construction of protective facilities The staff should take effective measures to control landslide disasters in combination with the actual needs of geological disaster control projects and the actual situation of slopes, and set up targeted protective facilities. In landslide control, scientific and reasonable protection facilities play a very important role, among which the simplest operation and the most obvious protection effect is the protective retaining wall, which has been widely used in slope control. Usually, the staff need to set a retaining wall below the landslide section to prevent landslide disasters. With the help of the retaining wall, the impact generated when the landslide slides can be blocked and the harm caused by the landslide can be minimized.

3.4 Prestressed anchorage Prestressed anchor cable and prestressed anchor beam are often used as treatment measures for landslide in open-pit mining, but there are still some shortcomings in the actual application process of this technology. For example, an open-pit mine adopts stress anchor cable technology to control the slope landslide in this area, which has great advantages in the investigation of the state of the slide body and the hydrogeological state, and can realize the effect of stabilizing the rock formation in the cave. After drilling the hole, the prestressed anchor rod is inserted and fixed to achieve the function of prestressed anchorage, and then the concrete is poured to replace the rock and soil mass of the fractured structure and the loose structure, so as to improve the mechanical strength of the rock mass. At the same time, this technology can prevent local picture penetration problems. It is usually equipped with about 40 steel bars, and the rebar connecting sleeve is connected to generate 8000kN tensile force and 7000kN shear resistance full-length viscose bolt. The section of the cavity section and the fault position is expanded to form a hole plug, which can improve the reinforcement effect of the rod body. When designing prestressed reinforced concrete anchorage structure, it is usually 25m in size and 60m in depth. Rebar is used for tension reinforcement, Φ16 rebar is selected as stirrup, C20 concrete is used to cast in the cave, M30 cement mortar is used for secondary grouting, and 4 prestressed anchor cables of 2700kN are used to fix the cave. The anchorage section with a length of about 12m, a passive tensile force of 10000kN and an active prestressing force of 10800kN was adopted to effectively control the landslide problem.