Slope stability analysis method for material partition of waste dump in open pit coal mine

Abstract

The invention discloses a slope stability analysis method for waste dump material partitions in an open pit coal mine, and belongs to the field of open pit coal mine waste material slope stability calculation. The method comprises the following steps: dividing an inner waste dump into different areas according to the development sequence of the inner waste dump of the opencast coal mine and the time period of the waste sequence; according to the particle size distribution rule of the waste of the inner waste dump, the inner waste dump is divided into areas with different particle sizes. The two areas are combined to finally form different areas of the waste dump, and physical and mechanical parameters including but not limited to density, internal friction angle, cohesive force, permeability coefficient and the like are systematically researched by adopting various means such as field test, indoor test, numerical simulation and the like for each subarea. Based on the physical and mechanical parameters of each subarea, the overall stability of the waste dump is comprehensively evaluated in combination with external factors such as side slope geometrical morphology, underground water conditions and climate conditions, the stability condition of the inner waste dump is truly and effectively reflected, and a powerful basis is provided for subsequent disposal plans and stability prevention and control.

Description

Technical Field

[0001] The invention relates to the technical field of slope stability monitoring of abandoned materials in open-pit coal mine dumps, and in particular to a slope stability analysis method for mechanical property zoning of abandoned materials in open-pit coal mine dumps. Background Art

[0002] With the continuous expansion of open-pit coal mining, the stability problem of the inner dump, as the main storage place for mine waste, has become increasingly prominent. Traditional slope stability analysis methods often make overall assessments based on unified physical and mechanical parameters, ignoring the development and changes of the dump in time series and the significant differences in material properties between different regions, resulting in deviations in the assessment results and difficulty in accurately reflecting the true stability of the inner dump. This affects the selection of treatment measures for the inner dump and the cost budget of the treatment measures.

[0003] The longer the dumping time of the inner dump steps is, the better the remodeling and bonding of the dumped materials is, and the greater the growth of cohesion and internal friction angle. In addition, the composition of dumped materials in different dumping sections is different, and their physical and mechanical indicators are significantly different. Therefore, the traditional method of unifying the physical parameters of rock and soil according to the dumped materials cannot truly reflect the actual stability of the site; the prevention and control measures and economic budget of the inner dump selected on this basis cannot achieve the corresponding effectiveness and economy. Summary of the invention

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a slope stability analysis method for material partitioning of a dump in an open-pit coal mine, the technical key points of which are: comprising the following steps: Obtain the internal dumping plan and the time for forming the internal dumping site, and divide the time periods according to the dumping time series, and divide the time for forming the internal dumping site into multiple time periods; Obtain the basic physical properties of different materials in the internal dumping ground and divide the internal dumping ground according to the particle size of the discarded materials; Combining different time series and different material particle size combinations in the inner dumping area, a new dumping area is formed, and the rock and soil in the area are sampled and tested to obtain the physical and mechanical parameters of the rock and soil in each new dumping area; The stability of the spoil dump is calculated using the mechanical parameters of the rock and soil in each area.

[0005] Preferably, the method for forming the new spoil dump area is: the area containing materials of the first particle size within a certain time period is taken as the first area; the area containing materials of the second particle size within the time period is taken as the second area; the area division of the time period is completed until materials of all particle sizes within the time period are distributed once; and the partitions within the next time period are set according to the same method; wherein the particle sizes of materials in different areas can be arranged in order from large to small or in order from small to large.

[0006] Preferably, the material particle size classification rule is: particles with a size of more than 250 mm are set as large block areas; particles with a size of 75-250 mm are set as medium block areas; and particles with a size of 2-75 mm are set as small block areas.

[0007] Preferably, the method for calculating the stability of the spoil dump is: using slope calculation software, inputting the mechanical parameters of the rock and soil in each area, and performing stability calculation.

[0008] Preferably, the next time series of earthwork materials are timely adjusted and continuously optimized based on the stability calculation results, materials with higher material properties are discarded to improve slope stability, and the geometric shape of the slope surface is optimized, and drainage paths are increased to reduce the impact of water on the slope.

[0009] The beneficial effects of the present invention are as follows: the present invention provides a slope stability analysis method for material partitions in an open-pit coal mine dump. According to the development sequence of the dump in the open-pit mine, the dump is divided into different areas according to the time periods of the dump; according to the particle size distribution law of the waste in the dump, the dump is divided into large-block areas, medium-block areas and small-block areas. The two division methods are combined to finally form different areas of the dump. For each partition, a variety of methods such as field tests, indoor tests and numerical simulations are used to systematically study its physical and mechanical parameters, including but not limited to density, internal friction angle, cohesion, permeability coefficient, etc. Based on the physical and mechanical parameters of each partition, combined with external factors such as slope geometry, groundwater conditions, and climatic conditions, a comprehensive assessment of the overall stability of the dump is conducted to truly and effectively reflect the stability of the dump, providing a strong basis for subsequent dumping plans and stability prevention and control. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic flow chart of a slope stability analysis method for mechanical property zoning of abandoned materials in an open-pit coal mine dump according to the present invention; Figure 2 It is a schematic diagram of the comprehensive area of ​​the slope of the abandoned material dump in the open-pit coal mine of the present invention; Figure 3 It is a schematic diagram of the slope of the abandoned material dump in the open-pit coal mine of the present invention at different time periods; Figure 4 It is a schematic structural diagram of different particle sizes of the abandoned material slope in the open-pit coal mine dump of the present invention. DETAILED DESCRIPTION

[0011] To make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the following is a brief description of the present invention in conjunction with the attached Figure 1-Figure 4 The present invention is further described in detail with reference to the accompanying drawings and specific embodiments.

[0012] This embodiment provides a slope stability analysis method for material partitions in an open-pit coal mine dump, comprising the following steps: Step 1: Conduct data research and on-site investigation on different dumping time periods in the internal dumping site, and divide the dumping site according to the dumping time. For example, if the internal dumping site is formed for 12 years, it is roughly divided into four time periods according to 1-3 years, 4-6 years, 7-9 years and 10-12 years. Each time period represents a specific dumping period and reflects the material deposition situation at different time points.

[0013] Step 2: Conduct data research and on-site investigation on different materials in the internal spoil dump, and divide the spoil dump according to the material particle size, such as large-particle area above 250mm (area 1), medium-particle area of ​​75~250mm (area 2) and small-particle area of ​​2~75mm (area 3).

[0014] Step 3: Combine Step 1 and Step 2 to finally form different areas of the dumping ground, for example, 11 different areas, as follows: Area 1: Material 1 in time period 1; Area 2: Material 1 in time period 2; Area 3: Material 1 in time period 3; Area 4: Material 1 in time period 4; Area 5: Material 2 in time period 1; Area 6: Material 2 in time period 2; Area 7: Material 2 in time period 3; Area 8: Material 2 in time period 4; Area 9: Material 3 in time period 2; Area 10: Material 3 in time period 3; Area 11: Material 3 in time period 4.

[0015] Step 4: Calculate the stability of the spoil dump using the mechanical parameters of the rock and soil in each area. Sampling and testing are carried out in the newly formed area to obtain the physical and mechanical parameters of the rock and soil in each area. The physical and mechanical properties of different areas are distinguished in detail, and then sampling and testing are carried out in each divided area to obtain the physical and mechanical parameters of the rock and soil, such as density, cohesion and internal friction angle. Modeling is carried out through slope calculation simulation software (such as Geo-slope), and the mechanical parameters of the rock and soil in each area are input to calculate and analyze the slope stability. Combined with the slope stability prediction results output by the model, a basis is provided for subsequent dumping plans and stability prevention and control. If poor stability is found, engineering measures such as optimizing the geometric shape of the slope surface, increasing drainage paths, and clearing the weak base layer can be adopted. After construction, the stability measurement is re-performed until the stability requirements for a period of time are met. This stability analysis method can truly and effectively reflect the stability of the spoil dump, provide a basis for on-site construction personnel, and improve the safety production control capabilities of mines.

[0016] The above generally describes the present invention in detail, but it is obvious to a person skilled in the art that some modifications or improvements can be made to the present invention. Therefore, modifications or improvements that do not depart from the spirit of the present invention are within the scope of protection of the present invention.

Claims

1. A slope stability analysis method for material partitions in an open-pit coal mine dump, characterized in that: The following steps are involved: Obtain the internal dumping plan and the time for forming the internal dumping site, and divide the time periods according to the dumping time series, and divide the time for forming the internal dumping site into multiple time periods; Obtain the basic physical properties of different materials in the internal dumping ground and divide the internal dumping ground according to the particle size of the discarded materials; Combining different time series and different material particle size combinations of the inner dumping area, a new inner dumping area is formed, and the rock and soil in the area are sampled and tested to obtain the physical and mechanical parameters of the rock and soil in each new dumping area; The stability of the inner dump is calculated using the mechanical parameters of the rock and soil in each area.

2. A method for analyzing the slope stability of a coal mine dump according to claim 1, characterized in that: The method for forming the new inner spoil dump area is as follows: the area containing materials of the first particle size within a certain time period is taken as the first area; the area containing materials of the second particle size within the time period is taken as the second area; the area division of the time period is completed after materials of all particle sizes within the time period are spread over once; the partitions within the next time period are set according to the same method; wherein the particle sizes of materials in different areas can be arranged in order from large to small or in order from small to large.

3. A method for analyzing the slope stability of a coal mine dump according to any one of claims 1 or 2, characterized in that: The material particle size classification rule is: the particle size above 250mm is set as the large block area; the particle size between 75-250mm is set as the medium block area; the particle size between 2-75mm is set as the small block area.

4. The method for analyzing slope stability of a dump in an open-pit coal mine according to claim 1, characterized in that: The method for calculating the stability of the inner dump is: using slope calculation software, inputting the mechanical parameters of the rock and soil in each area, and performing stability calculation.

5. A method for analyzing the slope stability of a coal mine dump according to claim 4, characterized in that: According to the stability calculation results, timely adjust and continuously optimize the next time series of earthwork materials, discard materials with higher material properties to improve slope stability, optimize the geometric shape of the slope surface, increase drainage paths and reduce the impact of water on the slope.

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