Safety protection methods for slopes in open-pit coal mines with sloping foundations

Abstract

This invention provides a method for safety protection of slopes in inclined open-pit coal mines, comprising: S1: setting up a first safety retaining wall on a horizontal section to stop falling rocks from the side of the horizontal section away from the inclined slope; excavating a stepped stage on the upslope section and excavating multiple sequentially connected stepped sections on the middle slope section; S2: filling the multiple stepped sections to form a fill layer, the top surface of the fill layer connecting with the bottom surface of the stepped stage to form a horizontal placement section, the top of the fill layer having a first rock-blocking structure for stopping falling rocks from the upslope section; S3: setting up a rubble retaining wall and a second rock-blocking structure on the stepped stage to stop falling rocks from the stepped stage or the horizontal section; S4: setting up a second safety retaining wall on the bottom surface of the stepped section adjacent to the downslope section to stop falling rocks from above the downslope section. This solution can solve the problem in the prior art of the impact of falling rocks and other debris on coal mining equipment and personnel safety in inclined open-pit coal mines.

Description

Technical Field

[0001] This invention relates to the field of slope protection technology for inclined open-pit coal mines, and more specifically, to a method for safety protection of inclined open-pit coal mine slopes. Background Technology

[0002] This invention primarily addresses slope safety protection methods in inclined open-pit coal mines. Currently, the inclined base slope of the mine is 1.3 km long, and after reaching the designed mining depth, the non-working slope length exceeds 2.2 km. Furthermore, the rock mass above the surface enclosure of the open-pit mining boundary is composed of igneous rock, with well-developed joints and fissures, making it prone to slope slippage; even after multiple treatments, a large number of sliding deformation zones remain. Because soil removal operations are not possible above the inclined base of the open-pit coal mine, the exposed area and length of the inclined base increase with mining depth. If slippage, rock weathering and collapse, or the formation of unstable rocks occur above the inclined slope, the sliding or rolling of the landslide or rock along the inclined base will pose a significant safety hazard to personnel working in deep coal mining operations. Therefore, effectively protecting against slippage and rockfalls from deep-mining equipment and personnel has become a crucial safety measure in inclined open-pit coal seam mining. Summary of the Invention

[0003] This invention provides a safety protection method for slopes in inclined open-pit coal mines, in order to solve the problem in the prior art where falling rocks and other debris on slopes in inclined open-pit coal mines affect the safety of coal mining equipment and personnel.

[0004] To address the aforementioned problems, this invention provides a method for safety protection of inclined base open-pit coal mine slopes. The inclined base open-pit coal mine slope includes a horizontal section and an inclined slope section. The inclined slope section includes an upslope section, a middle slope section, and a downslope section connected sequentially with the same inclination angle. The horizontal section and the upslope section are connected. The method for safety protection of inclined base open-pit coal mine slopes includes: S1: setting up a first safety retaining wall on the horizontal section to stop falling rocks from the side of the horizontal section away from the inclined slope section; excavating a stepped section on the upslope section; and excavating multiple sequentially connected stepped sections on the middle slope section; S2: ... 2: Fill multiple stepped sections to form a fill layer. The top surface of the fill layer and the bottom surface of the stepped section are connected to form a horizontal section. The inclination angle of the side of the fill layer is greater than the original inclination angle of the inclined slope section. The top of the fill layer has a first rock-blocking structure to stop the falling rocks from the uphill section; S3: Set up a rubble retaining wall on the stepped section to consolidate the structural strength of the uphill section. Build a second rock-blocking structure on the rubble retaining wall to stop the falling rocks from the stepped section or horizontal section; S4: Set up a second safety retaining wall on the bottom surface of the stepped section adjacent to the downhill section to stop the falling rocks from the downhill section.

[0005] Furthermore, S2 also includes: dividing the bottom surface of the step section adjacent to the downslope section into two parts, the part connected to the downslope section being a reserved area, and the part connected to the adjacent step section being a landfill area, and filling the landfill area and the remaining step sections to form a landfill layer; wherein, the inclination angle of the landfill layer relative to the horizontal plane is less than the inclination angle of the step section relative to the horizontal plane, and greater than the inclination angle of the downslope section relative to the horizontal plane.

[0006] Furthermore, S4 also includes: the width of the reserved area is greater than or equal to 3m, the second safety retaining wall is set in the reserved area, and the area surrounded by the second safety retaining wall, the reserved area, and the landfill layer forms the first stone-cutting ditch. When the original inclination angle of the inclined slope is less than 15°, the original inclination angle of the inclined slope is inversely proportional to the width of the reserved area, and the original inclination angle of the inclined slope is inversely proportional to the space of the first stone-cutting ditch.

[0007] Furthermore, in S1: the uphill section is divided into a first section and a second section that are connected to each other. The first section, which is connected to the middle slope section, is excavated to form a platform stage. The inclination angle of the platform stage relative to the horizontal plane is different from that of the second section relative to the horizontal plane. In S3: a rubble retaining wall is set on the inclined surface of the platform stage. The rubble retaining wall is a strip wall with a parallelogram cross-section. The top and bottom surfaces of the rubble retaining wall are parallel to the horizontal plane. The top surface of the rubble retaining wall is connected to the second section and there is an angle between them. A second rock-blocking structure is set on the top surface of the rubble retaining wall to stop the falling rocks from the second section.

[0008] Furthermore, in S3: the second rock-blocking structure includes a rock-blocking block and a rock-blocking net. The rock-blocking block is placed on the top surface of the rubble retaining wall and spaced apart from the second section. The area between the rock-blocking block, the rubble retaining wall, and the second section forms a second rock-blocking ditch to collect the rolling stones stopped by the rock-blocking block. The rock-blocking net is vertically placed on the rubble retaining wall on the side of the rock-blocking block away from the second section, and the rock-blocking net and the rock-blocking block are spaced apart in the horizontal direction. The rock-blocking net is used to stop the rolling stones that cross the rock-blocking block.

[0009] Furthermore, in S1: the inclination angle of the platform stage relative to the horizontal plane is greater than the inclination angle of the inclined base open-pit coal mine slope relative to the horizontal plane; the width of the horizontal portion of the step segment connected to the downslope segment is greater than the width of the horizontal portion of the other step segments, and the width of the horizontal portion of the other step segments is the same.

[0010] Furthermore, in S3: the landfill layer includes a landfill section and a rock-blocking protrusion disposed on the landfill section. The rock-blocking protrusion forms a first rock-blocking structure. The rock-blocking protrusion is located at one end of the water surface portion of the landfill section away from the platform stage. The landfill section and the rock-blocking protrusion are integrally formed.

[0011] Furthermore, the first safety retaining wall is a strip-shaped retaining wall with a trapezoidal cross-section, and the connection positions of the first safety retaining wall and the horizontal section and the inclined slope section are spaced apart, and the slope angle of the first safety retaining wall is greater than 30°.

[0012] Furthermore, the formula for calculating the thickness d of the rubble retaining wall is:

[0013] f2 = U*d;

[0014] Where f2 is the resistance capacity of the rubble retaining wall, U is the strength parameter, and d is the width of the rubble retaining wall.

[0015] Furthermore, the value of f2 is obtained through the following formula:

[0016] f1 = f2;

[0017] f1=τ1*L=r*h*tanφ*L+c*L;

[0018] Where f1 is the shear capacity of the rock mass of the inclined base open-pit coal mine slope excavated in S1, τ1 is the shear strength of the rock mass of the inclined base open-pit coal mine slope, c and φ are the shear strength indices of the rock mass of the inclined base open-pit coal mine slope, r is the rock mass weight of the inclined base open-pit coal mine slope, h is the maximum depth of the platform stage excavated in S1, and L is the slope length of the platform stage excavated in S1.

[0019] The present invention provides a method for safety protection of inclined base open-pit coal mine slopes. The inclined base open-pit coal mine slope includes a horizontal section and an inclined slope section. The inclined slope section includes an upslope section, a middle slope section, and a downslope section connected sequentially with the same inclination angle. The horizontal section and the upslope section are connected. The method for safety protection of inclined base open-pit coal mine slopes includes: S1: setting up a first safety retaining wall on the horizontal section to stop falling rocks from the side of the horizontal section away from the inclined slope section; excavating a stepped section on the upslope section; and excavating multiple sequentially connected stepped sections on the middle slope section; S2: ... The scheme involves: S1) Filling multiple stepped sections to form a fill layer. The top surface of the fill layer connects with the bottom surface of the stepped section to form a horizontal section. The inclination angle of the side of the fill layer is greater than the original inclination angle of the inclined slope section. The top of the fill layer has a first rock-blocking structure to stop falling rocks from the uphill section; S2) Installing a rubble retaining wall on the stepped section to reinforce the structural strength of the uphill section. Constructing a second rock-blocking structure on the rubble retaining wall to stop falling rocks from the stepped section or horizontal section; S3) Installing a second safety retaining wall on the bottom surface of the stepped section adjacent to the downhill section to stop falling rocks from the downhill section. This scheme, through the sequential installation of a first safety retaining wall, a second rock-blocking structure, and another first rock-blocking structure and a second safety retaining wall from top to bottom, achieves multi-level stopping of falling rocks and other debris from inclined open-pit coal mine slopes, avoiding the safety hazards present in existing inclined open-pit coal mine slope technologies. Furthermore, by excavating and backfilling the inclined slope sections of the sloping open-pit coal mine, a certain gradient is created in these sections, dispersing the total sliding length of the landslide rocks. This facilitates the fabrication of the second rock-blocking structure, the first rock-blocking structure, and the second safety retaining wall, as well as the interception of rocks falling at different gradients. Simultaneously, the backfill layer and rubble retaining wall can compensate for the structural strength of the sloping open-pit coal mine to a certain extent, preventing the surface of the excavated inclined slope section from being prone to rockfall due to reduced structural strength. On the other hand, this design facilitates the fabrication of the horizontal placement section, avoiding the difficulty of placing coal mining equipment on the slope as in existing technologies. This ensures the horizontal placement of the coal mining equipment. Furthermore, the backfill layer increases the area of ​​the horizontal placement section, providing more space for the placement of the coal mining equipment. The first rock-blocking structure also stops the coal mining equipment from moving downhill, ensuring the reliability of its placement. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0021] Figure 1 A flowchart of a method for protecting the slope of an open-pit coal mine with an inclined base, provided by an embodiment of the present invention, is shown.

[0022] Figure 2 This diagram shows a structural schematic of an inclined base open-pit coal mine slope with a first safety retaining wall installed in step S1.

[0023] Figure 3 A schematic diagram of the excavation of the inclined base open-pit coal mine slope in step S1 is shown;

[0024] Figure 4 A schematic diagram of the structure of the inclined base open-pit coal mine slope after step S1 is shown;

[0025] Figure 5 A schematic diagram of the structure of the inclined base open-pit coal mine slope after steps S2, S3 and S4 is shown.

[0026] The above figures include the following reference numerals:

[0027] 10. Horizontal section;

[0028] 20. Inclined slope section; 21. Uphill section; 211. Terrace section; 212. First section; 213. Second section; 22. Middle slope section; 221. Stepped section; 2211. Reserved area; 2212. Landfill area; 23. Downhill section;

[0029] 31. First safety retaining wall; 32. Rubble retaining wall; 33. Second rock-blocking structure; 331. Rock-cutting blocks; 332. Rock-blocking mesh; 34. Second safety retaining wall;

[0030] 40. Landfill layer; 41. First rock-blocking structure; 42. Landfill section;

[0031] 51. First stone-cutting ditch; 52. Second stone-cutting ditch. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0033] like Figures 1 to 5As shown, an embodiment of the present invention provides a method for safety protection of an inclined base open-pit coal mine slope, which is used for an inclined base open-pit coal mine slope. The inclined base open-pit coal mine slope includes a horizontal section 10 and an inclined slope section 20. The inclined slope section 20 includes an upslope section 21, a middle slope section 22 and a downslope section 23 connected in sequence with the same inclination angle. The horizontal section 10 and the upslope section 21 are connected. The method for safety protection of the inclined base open-pit coal mine slope includes: S1: setting up a first safety retaining wall 31 on the horizontal section 10 to stop falling rocks from the side of the horizontal section 10 away from the inclined slope section 20; excavating a stepped stage 211 on the upslope section 21 and excavating multiple stepped sections 221 connected in sequence on the middle slope section 22; S2: excavating multiple stepped sections 221. S1: Section 221 is filled to form a fill layer 40. The top surface of the fill layer 40 and the bottom surface of the platform section 211 are connected to form a horizontally placed section. The inclination angle of the side of the fill layer 40 is greater than the original inclination angle of the inclined slope section 20. The top of the fill layer 40 has a first rock-blocking structure 41 for stopping the falling rocks from the uphill section 21. S2: A rubble retaining wall 32 is set on the platform section 211 to consolidate the structural strength of the uphill section 21. A second rock-blocking structure 33 is built on the rubble retaining wall 32 to stop the falling rocks from the platform section 211 or the horizontal section 10. S3: A second safety retaining wall 34 is set on the bottom surface of the stepped section 221 adjacent to the downhill section 23 to stop the falling rocks from the downhill section 23.

[0034] In this embodiment, by sequentially setting a first safety retaining wall 31, a second rock-blocking structure 33, a first rock-blocking structure 41, and a second safety retaining wall 34 from top to bottom, multi-level blocking of falling rocks and other debris from the inclined open-pit coal mine slope is achieved, avoiding the safety hazards present in existing inclined open-pit coal mine slopes. Furthermore, by excavating and backfilling the inclined slope section 20 of the inclined open-pit coal mine slope, a certain gradient is created in the inclined slope section 20, dispersing the total sliding length of the landslide rocks. This facilitates the fabrication of the second rock-blocking structure 33, the first rock-blocking structure 41, and the second safety retaining wall 34, as well as the interception of rocks falling at different gradients. Simultaneously, by setting the backfill layer 40 and the rubble retaining wall 32, the structural strength of the inclined open-pit coal mine slope can be compensated to a certain extent, preventing the surface of the excavated inclined slope section from being prone to rockfall due to reduced structural strength. On the other hand, this arrangement facilitates the processing of the horizontal placement section, avoiding the situation in the prior art where it is not easy to place the coal mining equipment on the slope, ensuring the horizontal placement of the coal mining equipment. At the same time, this arrangement increases the area of ​​the horizontal placement section through the landfill layer 40, providing more space for the placement of the coal mining equipment. Meanwhile, the first rock-blocking structure 41 stops the movement of the coal mining equipment in the direction of the downhill section, ensuring the reliability of the placement of the coal mining equipment.

[0035] like Figures 2 to 5As shown, S2 further includes: dividing the bottom surface of the step section 221 adjacent to the downslope section 23 into two parts, the part connected to the downslope section 23 is the reserved area 2211, and the part connected to the adjacent step section 221 is the landfill area 2212, and the landfill area 2212 and the remaining step sections 221 are filled to form a landfill layer 40; wherein, the inclination angle of the landfill layer 40 relative to the horizontal plane is less than the inclination angle of the step section 211 relative to the horizontal plane and greater than the inclination angle of the downslope section 23 relative to the horizontal plane.

[0036] In this embodiment, by setting a reserved area 2211 to place the second safety retaining wall 34, the angle of the landfill layer 40 is limited. While ensuring its segmentation of the inclined slope section 20, it facilitates the increase in the area of ​​the horizontal placement section. It can be understood that if the inclination angle of the landfill layer 40 relative to the horizontal plane is equal to the original inclination angle of the inclined slope section 20, then the horizontal placement section only includes the bottom surface of the platform stage 211, and the second safety retaining wall 34 needs to be placed on the bottom surface of the platform stage 211, further reducing the area of ​​the horizontal placement section. This embodiment increases the area of ​​the horizontal placement section by adjusting the inclination angle of the landfill layer 40, ensuring the reliability of the coal mining equipment placement. The inclination angle of the landfill layer 40 is proportional to the increase in the area of ​​the horizontal placement section. The inclination angle of the landfill layer 40 is smaller than the inclination angle of the platform stage 211 relative to the horizontal plane to avoid an excessively steep inclination surface of the landfill layer 40, which would be detrimental to the filling of the landfill layer 40 and the guarantee of its structural strength.

[0037] like Figure 4 and Figure 5 As shown, S4 also includes: the width of the reserved area 2211 is greater than or equal to 3m, the second safety retaining wall 34 is set in the reserved area 2211, and the area surrounded by the second safety retaining wall 34, the reserved area 2211, and the landfill layer 40 forms the first stone-cutting ditch 51. When the original inclination angle of the inclined slope section 20 is less than 15°, the original inclination angle of the inclined slope section 20 is inversely proportional to the width of the reserved area 2211, and the original inclination angle of the inclined slope section 20 is inversely proportional to the space of the first stone-cutting ditch 51.

[0038] In this embodiment, the second safety retaining wall 34 is a strip-shaped retaining wall with an isosceles trapezoidal cross-section. The second safety retaining wall 34 is used to stop rolling objects such as boulders falling from the landfill layer 40. Since the two sides of the first intercepting ditch 51 are the two opposing inclined surfaces of the landfill layer 40 and the second safety retaining wall 34, the rolling objects after being stopped will accumulate in the first intercepting ditch 51, making it easy to clean up. This arrangement ensures that the space reserved in the reserved area 2211 is sufficient to install the second safety retaining wall 34 and to ensure the formation of the first intercepting ditch 51. Furthermore, by limiting the original inclination angle, the width of the reserved area 2211, and the space of the first intercepting ditch 51, the reliability of the first intercepting ditch 51 in stopping and accommodating rolling objects is ensured.

[0039] Alternatively, the second safety retaining wall 34 can also be a strip retaining wall with a cross-sectional shape of triangle, rectangle, trapezoid, etc., which will not be listed here.

[0040] Specifically, in S1: the uphill section 21 is divided into a first section 212 and a second section 213 that are connected to each other. The first section 212, which is connected to the middle slope section 22, is excavated to form a platform stage 211. The inclination angle of the platform stage 211 relative to the horizontal plane is different from that of the second section 213 relative to the horizontal plane. In S3: a rubble retaining wall 32 is set on the inclined surface of the platform stage 211. The rubble retaining wall 32 is a strip wall with a parallelogram cross-section. The top and bottom surfaces of the rubble retaining wall 32 are parallel to the horizontal plane. The top surface of the rubble retaining wall 32 is connected to the second section 213 and there is an angle between them. A second rock-blocking structure 33 is set on the top surface of the rubble retaining wall 32 to stop the falling rocks from the second section 213.

[0041] In this embodiment, the inclination angle of the second segment 213 relative to the horizontal plane is the original inclination angle of the inclined slope segment 20 relative to the horizontal plane. The inclination angle of the inclined surface of the platform stage 211 relative to the horizontal plane is greater than the inclination angle of the second segment 213 relative to the horizontal plane. The inclined surface of the platform stage 211 is divided into segments by the horizontal surface of the platform stage 211 and the inclined surface of the backfill layer 40. The rubble retaining wall 32 is set on the platform stage 211, which not only enhances the structural strength of the platform stage 211, but also facilitates the placement of the second rock-blocking structure 33. The top and bottom surfaces of the rubble retaining wall 32 are parallel to the horizontal plane, ensuring the reliability of the bottom end of the rubble retaining wall 32 on the horizontal surface of the platform stage 211. At the same time, it provides space for the placement of the second rock-blocking structure 33, avoiding the situation where the second rock-blocking structure 33 is difficult to place at the connection position between the second segment 213 and the platform stage 211, thus ensuring the reliability of the second rock-blocking structure 33.

[0042] Further, in S3: the second rock-blocking structure 33 includes a rock-blocking block 331 and a rock-blocking net 332. The rock-blocking block 331 is placed on the top surface of the rubble retaining wall 32 and spaced apart from the second section 213. The area between the rock-blocking block 331, the rubble retaining wall 32, and the second section 213 forms a second rock-blocking ditch 52 to collect the rolling stones stopped by the rock-blocking block 331. The rock-blocking net 332 is vertically placed on the rubble retaining wall 32 on the side of the rock-blocking block 331 away from the second section 213, and the rock-blocking net 332 and the rock-blocking block 331 are spaced apart in the horizontal direction. The rock-blocking net 332 is used to stop the rolling stones that cross the rock-blocking block 331.

[0043] In this embodiment, the rock-cutting block 331 is a strip-shaped stop with an isosceles trapezoidal cross-section. The rock-cutting block 331 is used to stop rolling stones and other debris falling from the second section 213. Since the two sides of the second rock-cutting ditch 52 are the rock-cutting block 331 and the two opposite inclined surfaces of the second section 213, the stopped debris will accumulate in the second rock-cutting ditch 52, facilitating centralized cleaning. The rubble retaining wall 32 facilitates the placement of the rock-cutting block 331 and forms the second rock-cutting ditch 52. Furthermore, the rubble retaining wall 32 facilitates the installation of the rock-blocking net 332. The height of the rock-blocking net 332 is higher than that of the rock-cutting block 331. The rock-blocking net 332 provides secondary stopping for rolling stones and other debris falling from the second section 213, preventing damage to coal mining equipment and workers located on the horizontally placed section from falling stones.

[0044] Optionally, the second safety retaining wall 34 is also made of riprap. The dimensions of the riprap blocks of the second safety retaining wall 34 and the second riprap structure 33 are different depending on their respective installation positions, so as to ensure the stopping and containment effects of the first riprap trench 51 and the second riprap trench 52 on rolling stones, respectively. When the original inclination angle of the inclined slope section 20 is less than 15°, the original inclination angle of the inclined slope section 20 is inversely proportional to the top width of the rubble retaining wall 32, and the original inclination angle of the inclined slope section 20 is inversely proportional to the containment space of the second riprap trench 52.

[0045] Alternatively, the cut-off block 331 can also be a strip-shaped stop block with a cross-sectional shape of triangle, rectangle, trapezoid, etc., which will not be listed here.

[0046] Specifically, in S1: the inclination angle of the platform stage 211 relative to the horizontal plane is greater than the inclination angle of the inclined base open-pit coal mine slope relative to the horizontal plane; the width of the horizontal portion of the step section 221 connected to the downslope section 23 is greater than the width of the horizontal portions of the other step sections 221, and the width of the horizontal portions of the other step sections 221 is the same. This arrangement facilitates the excavation and shaping of the platform stage 211 and the multiple step sections 221.

[0047] like Figure 5As shown in S3: the landfill layer 40 includes a landfill section 42 and a rock-blocking protrusion disposed on the landfill section 42. The rock-blocking protrusion forms a first rock-blocking structure 41. The rock-blocking protrusion is located at one end of the water surface portion of the landfill section 42 away from the platform stage 211. The landfill section 42 and the rock-blocking protrusion are integrally formed. This arrangement facilitates the direct processing of the rock-blocking protrusion during the landfilling and forming process of the landfill section 42. The top horizontal surface of the landfill section 42 and the bottom horizontal surface of the platform stage 211 are flush and connected to form a horizontally placed section. The rock-blocking protrusion serves to stop objects rolling down or coal mining equipment from sliding down on the horizontally placed section. Specifically, the rock-blocking protrusion is a protruding structure higher than the top surface of the landfill section 42. Its cross-sectional shape can be triangular, trapezoidal, rectangular, etc. In this embodiment, a strip-shaped protrusion with a triangular cross-sectional shape is used. One side is flush with the inclined surface of the landfill section 42, and the other side has an angle with the top horizontal surface of the landfill section 42.

[0048] Furthermore, the first safety retaining wall 31 is a strip-shaped retaining wall with a trapezoidal cross-section. The connection points between the first safety retaining wall 31 and the horizontal section 10 and the inclined slope section 20 are spaced apart, and the slope angle of the first safety retaining wall 31 is greater than 30°. This arrangement facilitates the installation of the first safety retaining wall 31, which, by limiting the slope angle, ensures its effectiveness in stopping falling stones.

[0049] Specifically, the formula for calculating the thickness d of the rubble retaining wall 32 is: f2 = U * d; where f2 is the resistance capacity of the rubble retaining wall 32, U is the strength parameter, and d is the width of the rubble retaining wall 32. This setting facilitates the calculation of the thickness of the rubble retaining wall 32, ensuring its compensation for the structural strength of the excavated uphill section 21, and avoiding the situation where the structural strength of the uphill section 21 decreases after excavation, making it prone to damage and collapse. U is 1 / 20 of the design strength MU30 of the rubble retaining wall 32.

[0050] Furthermore, the value of f2 is obtained through the following calculation formula: f1 = f2; f1 = τ1 * L = r * h * tanφ * L + c * L; where f1 is the shear capacity of the rock mass of the inclined base open-pit coal mine slope excavated in S1, τ1 is the shear strength of the rock mass of the inclined base open-pit coal mine slope, c and φ are the shear strength indices of the rock mass of the inclined base open-pit coal mine slope, r is the density of the rock mass of the inclined base open-pit coal mine slope, h is the maximum depth of the platform stage 211 excavated in S1, and L is the slope length of the platform stage 211 excavated in S1. This setting allows for the calculation of f2 by making f1 and f2 equal, thereby enabling the calculation of the thickness d of the rubble retaining wall 32. Shear strength refers to the ultimate strength when an external force is perpendicular to the material axis and exerts a shearing effect on the material. In the above formula, c is the cohesion of the rock mass of the inclined open-pit coal mine slope, and φ is the internal friction angle of the rock mass of the inclined open-pit coal mine slope. Both are shear strength indicators of the rock mass of the inclined open-pit coal mine slope. Since the calculation method of shear strength is relatively conventional, the parameters will not be described in detail here. In this embodiment, c = 110 kPa, φ is 32°, and r is 23 kg / m. 3 The calculated value of d is 0.77m, and the design value is 0.8m.

[0051] Among them, such as Figures 2 to 5 The dimensions shown are those of the current embodiment, and specific dimensions may be adjusted according to actual conditions. Specifically, the dimensions of the first safety retaining wall 31 are applicable when the length of the horizontal section is 25m, the inclination angle of the preceding inclined slope section connected to the horizontal section is 30°, and the height is 10m. Corresponding to the dimensions shown, the height of the rockfall netting 332 is 1m, the width at the connection point between the cut-off rock 331 and the rubble retaining wall 32 is 0.8m, the thickness of the rubble retaining wall 32 is 0.8m, and the inclination angle of the rubble retaining wall 32 is the same as that of the platform stage 211, both being 45°. The distance from the connection point between the downslope section 23 and the middle slope section 22 of the second safety retaining wall 34 is 0.5m, the height and top width of the second safety retaining wall 34 are both 0.5m, and the inclination angle is 35°.

[0052] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0053] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0054] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0055] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0056] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0057] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for safety protection of slopes in inclined open-pit coal mines, used for slopes in inclined open-pit coal mines, wherein the inclined slope includes a horizontal section (10) and an inclined slope section (20), the inclined slope section (20) including an upslope section (21), a middle slope section (22), and a downslope section (23) connected in sequence with the same inclination angle, the horizontal section (10) and the upslope section (21) being connected, characterized in that, The safety protection methods for inclined open-pit coal mine slopes include: S1: A first safety retaining wall (31) is set on the horizontal section (10) to stop the falling rocks from the side of the horizontal section (10) away from the inclined slope section (20); a platform stage (211) is excavated on the upslope section (21), and multiple stepped sections (221) are excavated in sequence on the middle slope section (22); the upslope section (21) is divided into a first section (212) and a second section (213) that are connected to each other, and the first section (212) connected to the middle slope section (22) is excavated to form the platform stage (211), and the inclination angle of the platform stage (211) relative to the horizontal plane is different from the inclination angle of the second section (213) relative to the horizontal plane; S2: The multiple stepped sections (221) are filled to form a fill layer (40), the top surface of the fill layer (40) and the bottom surface of the stepped section (211) are connected to form a horizontally placed section, the inclination angle of the side of the fill layer (40) is greater than the original inclination angle of the inclined slope section (20), the top of the fill layer (40) has a first rock-blocking structure (41) for stopping the falling rocks from the uphill section (21); the bottom of the stepped section (221) adjacent to the downhill section (23) is connected to the bottom of the stepped section (221). The surface is divided into two parts: the part connected to the downslope section (23) is the reserved area (2211), and the part connected to the adjacent stepped section (221) is the landfill area (2212). The landfill area (2212) and the remaining stepped sections (221) are filled to form a landfill layer (40); wherein, the inclination angle of the landfill layer (40) relative to the horizontal plane is smaller than the inclination angle of the stepped section (211) relative to the horizontal plane and larger than the inclination angle of the downslope section (23) relative to the horizontal plane; S3: A rubble retaining wall (32) is installed on the platform stage (211) to reinforce the structural strength of the uphill section (21). A second rock-blocking structure (33) is constructed on the rubble retaining wall (32) to stop the falling rocks from the platform stage (211) or the horizontal section (10). The rubble retaining wall (32) is set on the inclined surface of the platform stage (211). The rubble retaining wall (32) is a strip wall with a parallelogram cross-section. The top and bottom surfaces of the rubble retaining wall (32) are parallel to the horizontal plane. The top surface of the rubble retaining wall (32) is connected to the second section (213) and there is an angle between them. The second rock-blocking structure (33) is set on the top surface of the rubble retaining wall (32) to stop the falling rocks from the second section (213). The second rock-blocking structure (33) includes a rock-blocking block (331) and a rock-blocking net (332). The rock-blocking block (331) is placed on the top surface of the rubble retaining wall (32) and spaced apart from the second section (213). The area between the rock-blocking block (331), the rubble retaining wall (32) and the second section (213) forms a second rock-blocking ditch (52) to collect the rolling stones blocked by the rock-blocking block (331). The rock-blocking net (332) is vertically placed on the rubble retaining wall (32) on the side of the rock-blocking block (331) away from the second section (213), and the rock-blocking net (332) and the rock-blocking block (331) are spaced apart in the horizontal direction. The rock-blocking net (332) is used to stop the rolling stones that cross the rock-blocking block (331). S4: A second safety retaining wall (34) is set on the bottom surface of the stepped section (221) adjacent to the downslope section (23) to stop the falling stones from the downslope section (23); the width of the reserved area (2211) is greater than or equal to 3m, the second safety retaining wall (34) is set in the reserved area (2211), and the area surrounded by the second safety retaining wall (34), the reserved area (2211), and the landfill layer (40) forms a first stone-cutting ditch (51). When the original tilt angle of the inclined slope section (20) is less than 15°, the original tilt angle of the inclined slope section (20) is inversely proportional to the width of the reserved area (2211), and the original tilt angle of the inclined slope section (20) is inversely proportional to the space of the first stone-cutting ditch (51).

2. The method for safety protection of inclined open-pit coal mine slopes according to claim 1, characterized in that, In S1: The inclination angle of the platform stage (211) relative to the horizontal plane is greater than the inclination angle of the inclined base open-pit coal mine slope relative to the horizontal plane; the width of the horizontal portion of the step section (221) connected to the downslope section (23) is greater than the width of the horizontal portion of the other step sections (221), and the width of the horizontal portion of the other step sections (221) is the same.

3. The method for safety protection of inclined open-pit coal mine slopes according to claim 1, characterized in that, In S3: The landfill layer (40) includes a landfill section (42) and a rock-blocking protrusion disposed on the landfill section (42). The rock-blocking protrusion forms the first rock-blocking structure (41). The rock-blocking protrusion is located at one end of the water surface portion of the landfill section (42) away from the platform stage (211). The landfill section (42) and the rock-blocking protrusion are integrally formed.

4. The method for safety protection of inclined open-pit coal mine slopes according to claim 1, characterized in that, The first safety retaining wall (31) is a strip retaining wall with a trapezoidal cross section. The connection positions of the first safety retaining wall (31) and the horizontal section (10) and the inclined slope section (20) are spaced apart. The slope angle of the first safety retaining wall (31) is greater than 30°.

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