A reinforcement method for controlling uneven settlement and slope stability of spoil heaps

Abstract

This invention discloses a reinforcement method for controlling uneven settlement and slope stability of spoil heaps. The method utilizes numerical simulation to calculate the most dangerous sliding surface of the planned spoil heap slope. The slope is constructed in stages, from bottom to top. In the first stage, odd-numbered steps are constructed directly, while even-numbered steps are constructed by covering them with reinforced soil. Micropiles are installed on the platform and slope of all odd-numbered steps except the topmost step. After the first stage is completed, the second stage begins, with the construction method of each step in the second stage being the reverse of that in the first stage. This completes one construction cycle. Construction can continue according to the construction cycle as needed. This combined reinforcement method can improve the comprehensive mechanical properties of the soil and rock mass of the spoil heap slope, enhance the structural integrity and stability of the spoil heap, effectively solve the problem of uneven settlement in spoil heaps, and improve slope stability.

Description

Technical Field

[0001] This invention relates to a method for reinforcing the slope of a spoil heap, specifically a method for controlling uneven settlement and slope stability of a spoil heap. Background Technology

[0002] Open-pit mine spoil heaps, as an important component of mining activities, are areas used to dispose of mine waste. Currently, many large open-pit mines are located in northern and northwestern my country, and their spoil heaps generally suffer from problems such as large land area occupation, insufficient land acquisition, and uneven settlement. Currently, open-pit mines often use methods such as optimizing spoil heap slopes and improving spoil disposal strategies to alleviate these problems. However, while these methods often achieve the goal of expanding spoil disposal space, they reduce the stability of the spoil heap. Therefore, how to control uneven settlement of spoil heaps and improve the stability of spoil heap slopes is of great significance for preventing spoil heap collapses, landslides, and other accidents, and for improving the sustainable development of open-pit mines. Summary of the Invention

[0003] To address the problems existing in the prior art, this invention provides a reinforcement method for regulating uneven settlement and slope stability of spoil heaps, which can effectively solve the problem of uneven settlement in spoil heaps and improve slope stability.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a reinforcement method for regulating uneven settlement and slope stability of spoil heaps, comprising the following steps:

[0005] S1: Conduct experimental measurements of the physical and mechanical parameters of the slope of the planned spoil heap;

[0006] S2: Using numerical simulation analysis, based on the structure of the planned spoil heap slope and the measured physical and mechanical parameters, a numerical model of the planned spoil heap slope is established in the slope analysis software. After inputting the physical and mechanical parameters, stability calculation is performed, and the most dangerous sliding surface of the planned spoil heap slope is obtained through calculation.

[0007] S3: Taking ΔL as the distance of one advancement and reinforcement cycle, starting from the foundation of the spoil heap, the planned spoil heap slope is constructed in steps from bottom to top. The odd-numbered steps of the first advancement and reinforcement cycle are constructed directly, while the even-numbered steps are constructed by covering them with reinforced soil. Except for the uppermost step, micro pile groups are set on the step plate and the step slope of all odd-numbered steps, and the micro pile groups set on the step plate extend into two rows.

[0008] S4: After the first reinforcement cycle is completed, the construction of the second reinforcement cycle, with a distance of ΔL, begins. Starting from the spoil heap base, the planned spoil heap slope is constructed in steps from bottom to top, building upon the foundation of the first reinforcement cycle. The construction method of each step in the second reinforcement cycle is the opposite of the corresponding step construction method in the first reinforcement cycle, so that even-numbered steps are constructed directly, while odd-numbered steps are covered with reinforced soil. Micropiles are installed on the step plate and slope of all even-numbered steps except the bottommost step, and the micropiles on the step plate extend two rows inward. This completes one construction cycle.

[0009] S5: After the second reinforcement cycle is completed, refer to steps S3 and S4 to start the next construction cycle until the construction of the entire planned spoil heap slope is completed.

[0010] Furthermore, the length of the micro-piles extends from the installation position to 3m below the bottom surface of the step.

[0011] Furthermore, the endpoint of the reinforced soil paving is 10m outside the most dangerous sliding surface.

[0012] Furthermore, the reinforced soil is composed of geogrids and filling material, with multiple geogrid cells evenly opened on the geogrids and the filling material poured into the geogrid cells.

[0013] Furthermore, after the filling material is injected into the geocell of the geogrid, the reinforced soil is compacted.

[0014] Furthermore, the filling material can be in-situ soil or gravel from the slope of the planned spoil heap.

[0015] Furthermore, the piles in the micro-piles are rigid piles.

[0016] Compared with existing technologies, this invention uses numerical simulation to calculate the most dangerous sliding surface of the planned spoil heap, and then designs a combination of reinforced soil and micropiles in an alternating arrangement, which is carried out in conjunction with the construction of the existing spoil heap layer by layer. The reinforced soil can be made by combining geogrids and geotextiles, and the micropiles can be made of steel pipes, wooden piles, plain concrete piles, or reinforced cement concrete piles, reducing the production cost and ensuring the reinforcement effect. This combined reinforcement method can improve the comprehensive mechanical properties of the soil and rock mass of the spoil heap slope, enhance the structural integrity and stability of the spoil heap, effectively solve the problem of uneven settlement of the spoil heap, and improve the stability of the slope. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0019] Figure 2 This is a schematic diagram of the reinforced soil structure of the present invention;

[0020] Figure 3 This is a schematic diagram illustrating the reinforcement principle of the present invention;

[0021] Figure 4 This is a schematic diagram of the single-step encapsulation structure of the reinforced soil of the present invention;

[0022] Figure 5 This is a schematic diagram of the first reinforcement scheme for the reinforcement cycle of this invention;

[0023] Figure 6 This is a schematic diagram of the reinforcement scheme for the second reinforcement cycle of the present invention.

[0024] The above figures include the following reference numerals:

[0025] 1. Planning of spoil heap slope; 2. Stepped flat plate; 3. Most dangerous sliding surface; 4. Reinforced soil; 5. Geogrid; 6. Filling material; 7. Micro pile group; 8. End point; 9. Spoil heap base; 10. Step top surface; 11. Step slope; 12. Step bottom surface. Detailed Implementation

[0026] The invention will now be further described with reference to the accompanying drawings.

[0027] 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] This invention provides a technical solution, such as Figures 1 to 6 As shown, it includes the following steps:

[0029] The physical and mechanical parameters of the soil and rock mass of the planned spoil heap slope 1, such as unit weight γ, cohesion C, and internal friction angle φ, were experimentally determined. The unit weight γ was determined by weighing method, and the cohesion C and internal friction angle φ were determined by direct shear test. Based on the structure of the planned spoil heap slope 1 and the measured physical and mechanical parameters, a numerical model of the planned spoil heap slope 1 was established in the slope analysis software and the physical and mechanical parameters were input. The most dangerous sliding surface 3 of the planned spoil heap slope 1 was calculated by numerical simulation analysis method.

[0030] Let ΔL be the distance of one reinforcement cycle, such as Figure 5 As shown, starting from the foundation 9 of the spoil heap, the planned spoil heap slope 1 is constructed in steps from bottom to top. The odd-numbered steps of the first reinforcement cycle are constructed directly, while the even-numbered steps are covered by reinforced soil 4. The endpoint 8 of the reinforced soil 4 is 10m outside the most dangerous sliding surface 3 in the stability analysis results of the planned spoil heap slope 1. Figure 2 As shown, the reinforced soil 4 consists of geogrids 5 and filling material 6. Multiple geogrid cells are evenly distributed on the geogrids 5. The method of laying the reinforced soil 4 is to first lay the geogrids 5, and then pour the filling material 6 into the geogrid cells of the geogrids 5 to ensure uniform filling. After the filling material 6 is poured into the geogrid cells of the geogrids 5, the reinforced soil 4 is appropriately compacted to improve its density and overall strength. In order to prevent the geogrids 5 from being mechanically damaged during construction, a backfill layer of not less than 25cm thick needs to be maintained between the geogrids 5 and the compaction machine. When two adjacent geogrids 5 are connected, they need to be connected together with fixing objects to ensure that the connection part is fully fixed. The filling material 6 can be the in-situ soil or crushed stone of the planned spoil heap slope 1. Except for the topmost step, all odd-numbered steps have micropiles 7 installed on the step platform 2 and step slope 11, with two rows of micropiles 7 extending inward from the step platform 2. The piles in the micropiles 7 are rigid piles, made of steel pipe, wood, cement, concrete, or reinforced concrete, and are vertically driven into the soil-removing steps using a rammer. Figure 4 As shown, two rows of micropiles 7 extending into the interior of the step plate 2 coincide with the slope surface 11 of the upper step. These two rows of micropiles 7 can be compacted into the geocells of the geogrid 5 on the slope surface 11. The micropiles 7 are in close contact with the soil of the spoil heap. The length of the micropiles 7 extends from the installation position to 3m below the bottom surface 12 of the step. Figure 3As shown, the reinforced soil 4 bears the self-weight and external load of the spoil heap slope and is transferred to the interior of the reinforced soil 4 through the geogrid 5. During the transfer process, the reinforced soil 4 and the soil of the spoil heap slope will have a displacement difference. At this time, the frictional resistance and the lateral soil stress are in opposite directions, thereby improving the anti-sliding and anti-overturning stability of the overall slope structure. The micro pile group 7 can provide support force to prevent the bulk material of the spoil heap from deforming and moving towards the free face. The micro pile group 7 is distributed on the adjacent upper step slope 11, which can realize the connection between the reinforced soil 4 of the adjacent upper step slope 11 and the bottom surface 12 of the step and the reinforced soil 4 of the adjacent lower step top surface 10, so as to achieve the overall reinforcement effect and reinforce the steps without reinforced soil 4.

[0031] After the first reinforcement cycle is completed, the construction of the second reinforcement cycle, with a distance of ΔL, begins, as follows: Figure 6 As shown, starting from the spoil heap base 9, based on the construction of the first reinforcement cycle, the planned spoil heap slope 1 is constructed in steps from bottom to top. The construction method of each step in the second reinforcement cycle is the opposite of the corresponding step construction method in the first reinforcement cycle, so that even-numbered steps are constructed directly, and odd-numbered steps are constructed by covering them with reinforced soil 4. The reinforced soil 4 in the second reinforcement cycle uses the top of the micro pile group 7 in the first reinforcement cycle as the anchor point, and also serves as the crown beam of the micro pile group 7 in the second reinforcement cycle, realizing the joint reinforcement of reinforced soil 4 and micro pile group 7. Except for the lowest step, micro pile group 7 is set on the step plate 2 and step slope 11 of all even-numbered steps, and the micro pile group 7 set on the step plate 2 extends into it in two rows. This completes one construction cycle.

[0032] After the second reinforcement cycle is completed, as Figure 1 As shown, follow the steps above to begin the next construction cycle until the construction of the entire planned spoil heap slope 1 is completed.

[0033] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0034] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any minor modifications, equivalent substitutions, and improvements made to the above embodiments based on the technical essence of the present invention should be included within the protection scope of the present invention.

Claims

1. A reinforcement method for controlling uneven settlement and slope stability of spoil heaps, characterized in that, Includes the following steps: S1: The physical and mechanical parameters of the slope (1) of the planned spoil heap were experimentally determined; S2: Using numerical simulation analysis, based on the structure of the planned spoil heap slope (1) and the measured physical and mechanical parameters, a numerical model of the planned spoil heap slope (1) is established in the slope analysis software. After inputting the physical and mechanical parameters, stability calculation is performed, and the most dangerous sliding surface (3) of the planned spoil heap slope (1) is obtained through calculation. S3: Taking ∆L as the distance of one advancement and reinforcement cycle, starting from the base (9) of the spoil heap, the planned spoil heap slope (1) is constructed in steps from bottom to top. The odd-numbered steps of the first advancement and reinforcement cycle are directly constructed, and the even-numbered steps are constructed by covering the reinforced soil (4). Except for the uppermost step, all odd-numbered steps have micro pile groups (7) on the step plate (2) and step slope (11), and the micro pile groups (7) on the step plate (2) extend into the interior in two rows. S4: After the first reinforcement cycle is completed, the construction of the second reinforcement cycle with a distance of ∆L begins. Starting from the spoil heap base (9), based on the construction of the first reinforcement cycle, the planned spoil heap slope (1) is constructed step by step from bottom to top. The construction method of each step in the second reinforcement cycle is the opposite of the construction method of the corresponding step in the first reinforcement cycle, so that even-numbered steps are constructed directly, and odd-numbered steps are constructed by covering the reinforced soil (4). Except for the bottommost step, the step plate (2) and the step slope (11) of all even-numbered steps are provided with micro pile groups (7), and the micro pile groups (7) provided on the step plate (2) extend into the interior in two rows. Thus, one construction cycle is completed. S5: After the second reinforcement cycle is completed, refer to steps S3 and S4 to start the next construction cycle until the construction of the entire planned spoil heap slope (1) is completed; The reinforced soil (4) is composed of geogrid (5) and filling material (6). Multiple geogrid cells are evenly opened on the geogrid (5), and the filling material (6) is poured into the geogrid cells.

2. The reinforcement method for regulating uneven settlement and slope stability of a spoil heap according to claim 1, characterized in that, The length of the micro pile group (7) extends from the installation position to 3m below the bottom surface (12) of the step.

3. The reinforcement method for regulating uneven settlement and slope stability of a spoil heap according to claim 1, characterized in that, The endpoint (8) of the reinforced soil (4) is 10m outside the most dangerous sliding surface (3).

4. The reinforcement method for regulating uneven settlement and slope stability of a spoil heap according to claim 1, characterized in that, After the filling material (6) is poured into the geocell of the geogrid (5), the reinforced soil (4) is compacted.

5. The reinforcement method for regulating uneven settlement and slope stability of a spoil heap according to claim 1, characterized in that, The filling material (6) is either the in-situ soil of the planned spoil heap slope (1) or crushed stone.

6. The reinforcement method for regulating uneven settlement and slope stability of a spoil heap according to claim 1, characterized in that, The piles in the micro pile group (7) are rigid piles.

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