A waterproof and drainage system for a soft rock open-pit mine inner dump

Abstract

The application belongs to the technical field of mine drainage and waterproofing, and particularly relates to a waterproof and drainage system for a soft rock open-pit mine internal dump. The application provides a waterproof and drainage system for a soft rock open-pit mine internal dump, which comprises a waterproof cover layer and a drainage ditch. The waterproof cover layer covers the surface of the slope of the internal dump, and the drainage ditch is arranged at the bottom end of the slope of the internal dump. In the technical scheme provided by the application, the waterproof cover layer covering the surface of the slope can effectively prevent the seepage water of the slope from entering the internal dump, reduce the amount of external water of the internal dump, and avoid the potential risk of increased water content. At the same time, the drainage ditch provides a water outlet channel, accelerates the flow of accumulated water, avoids the accumulation of accumulated water at the bottom of the slope, prevents the accumulated water from affecting the slope stability of the internal dump, and solves the technical defects of poor drainage effect and inability to guarantee the slope stability of the internal dump in the prior art.

Description

Technical Field

[0001] This application belongs to the field of mine drainage technology, and in particular relates to a drainage system for spoil heaps in soft rock open mines. Background Technology

[0002] Open-pit mines for soft rock refer to open-pit mining projects where the target material is soft rock (compressive strength ≤30MPa, such as mudstone, shale, sandy mudstone, weathered granite, etc.). Soft rock is characterized by its tendency to soften easily when exposed to water, a sharp drop in strength, and poor stability. These mines often have water-rich geological features and poor soil permeability. During internal drainage operations, the accumulated water in the internal drainage area is difficult to drain, leading to increased soil moisture content, reduced shear strength, and a high risk of landslides, collapses, and water accumulation at the bottom of the pit. This can result in safety accidents, seriously affecting normal mine production and personnel safety.

[0003] Currently, there are some conventional methods for drainage and waterproofing of spoil heaps in soft rock open-pit mines, such as setting up simple drainage ditches. However, these methods are ineffective in situations with abundant water and poor soil permeability, making it difficult to effectively solve the problem of water accumulation in spoil heaps and failing to fully guarantee the slope stability of spoil heaps.

[0004] Therefore, the development of a drainage system for spoil heaps in soft rock open-pit mines is a pressing issue that needs to be addressed by those skilled in the art, as spoil heaps suffer from poor drainage and the inability to ensure slope stability. Summary of the Invention

[0005] Therefore, it is necessary to provide a drainage system for internal spoil heaps in soft rock open mines, addressing the technical shortcomings of existing technologies, such as poor drainage and inability to guarantee slope stability.

[0006] This application provides a drainage system for a spoil heap in a soft rock open-pit mine. The drainage system includes a waterproof covering layer and a drainage ditch. The waterproof covering layer covers the slope surface of the spoil heap, and the drainage ditch is located at the bottom of the slope of the spoil heap.

[0007] In one embodiment, the drainage system further includes a backfill layer disposed inside the drainage ditch.

[0008] In one embodiment, the drainage system further includes a water guide pipe laid on the upper surface of the backfill layer, the water guide pipe being laid in the same direction as the extension direction of the drainage ditch.

[0009] In one embodiment, the waterproof covering layer includes: a plurality of longitudinally parallel composite geomembranes, with an overlap width of more than 10 centimeters between adjacent geomembranes.

[0010] In one embodiment, the composite geomembrane comprises a polyethylene film and a geotextile.

[0011] In one embodiment, the polyethylene film has a thickness greater than 1.0 mm, and the geotextile has a specification greater than 150 g / m². 2 .

[0012] In one embodiment, the drainage ditch is trapezoidal, wider at the top and narrower at the bottom, with a top width of 1.0-1.5 meters, a bottom width of 0.5-0.8 meters, and a depth of 0.8-1.2 meters.

[0013] In one embodiment, the bottom of the drainage ditch has a slope with an angle of 2‰-5‰.

[0014] In one embodiment, the backfill layer comprises: layered rubble, wherein the thickness of a single layer of rubble is 30-50 cm, the particle size of the rubble is 20-40 cm, and the compressive strength of the rubble is 25 MPa.

[0015] In one embodiment, the water guide pipe has a diameter of 100-150 mm and is provided with a plurality of water-permeable holes with a diameter of 6 mm, and the spacing between adjacent water-permeable holes is 12 mm.

[0016] In summary, this application provides a drainage system for an internal spoil heap in a soft rock open-pit mine, comprising: a waterproof covering layer and a drainage ditch; the waterproof covering layer covers the slope surface of the internal spoil heap, and the drainage ditch is located at the bottom of the slope of the internal spoil heap. In the technical solution provided by this application, the waterproof covering layer on the slope surface can effectively prevent seepage water from entering the internal spoil heap, reducing the amount of external water entering the internal spoil heap and avoiding potential risks due to increased moisture content; simultaneously, the drainage ditch provides an outlet channel, accelerating the flow of accumulated water, preventing water accumulation at the bottom of the slope, and preventing water accumulation from affecting the slope stability of the internal spoil heap. This solves the technical defects of existing internal spoil heaps, such as poor drainage and inability to guarantee slope stability. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0018] Figure 1A schematic diagram of the drainage system for a spoil heap in a soft rock open-pit mine, provided in the technical solution of this application embodiment; Figure 2 A schematic diagram of the laying process of a drainage system for a spoil heap in a soft rock open-pit mine, provided in the technical solution of this application embodiment; The components include a waterproof covering layer 1, a drainage ditch 2, a backfill layer 3, and a water pipe 4. Detailed Implementation

[0019] This application provides a drainage system for an internal spoil heap in a soft rock open-pit mine. However, internal spoil heaps suffer from technical defects such as poor drainage and inability to ensure the stability of the slope.

[0020] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0021] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and 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 of this application.

[0022] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0023] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0024] Please see Figure 1 This application provides a drainage system for a spoil heap in a soft rock open-pit mine, including: a waterproof covering layer 1 and a drainage ditch 2; the waterproof covering layer 1 covers the slope surface of the spoil heap, and the drainage ditch 2 is located at the bottom of the slope of the spoil heap.

[0025] This application provides a drainage system for an inner spoil heap in a soft rock open-pit mine. A waterproof covering layer 1 is applied to the slope surface of the inner spoil heap, effectively preventing seepage water from the slope into the spoil heap, reducing the amount of external water entering the spoil heap, and blocking the seepage path at its source, thus avoiding potential risks due to increased moisture content. Because the waste material in the inner spoil heap is loose and highly permeable, and the soft rock base contains minerals such as montmorillonite, it easily disintegrates when exposed to water. After contact with water, its mechanical strength and shear capacity decrease significantly, easily forming a weak sliding layer. The waterproof covering layer 1 provided in this application, after covering the slope, effectively blocks atmospheric precipitation and surface runoff from seeping into the spoil heap and its base, preventing soft rock mudification caused by groundwater accumulation, and reducing the root causes of slope instability.

[0026] Meanwhile, drainage ditch 2 provides an efficient drainage channel for the internal spoil heap, improving the timeliness of drainage. Unlike existing technologies where drainage facilities in traditional spoil heaps are scattered and rainwater easily stagnates and infiltrates on the slope, exacerbating slope pressure, the technical solution provided in this application provides a centralized water collection system at the bottom of the slope, which can quickly collect external water sources such as rainwater flowing across the slope, preventing rainwater from overflowing and washing away the spoiled materials, quickly discharging small amounts of locally infiltrated water, reducing pore water pressure on the slope, and solving the problems of low drainage efficiency and difficulty in draining accumulated water.

[0027] The drainage system, consisting of a waterproof cover layer 1 and a drainage ditch 2, provides dual protection for slope stability and reduces the risk of disasters. On one hand, the waterproof cover layer 1 reduces the erosion and softening of the spoil heap material and the underlying soft rock by seepage; on the other hand, the drainage ditch 2 quickly drains surface runoff. The synergistic effect of these two systems effectively prevents landslides and collapses caused by material saturation and slippage of weak layers in the soft rock. The drainage system provided in this application is simple in structure and adaptable to the characteristics of loose materials and terrain conditions in spoil heaps within soft rock open-pit mines. While improving slope stability, it simplifies the construction and maintenance of drainage facilities, balancing safety and economy, and providing a reliable guarantee for the long-term stable operation of the spoil heap.

[0028] In practical applications, for multiple continuous internal spoil heap slopes, drainage ditches 2 can be set at the bottom of each slope, and waterproof covering layer 1 can continuously cover multiple continuous slopes from top to bottom.

[0029] To further optimize the technical solution and improve the permeability of the drainage ditch 2, the drainage system provided in this application embodiment also includes a backfill layer 3, which is disposed inside the drainage ditch 2. The drainage ditch 2 with the backfill layer 3 can accelerate the flow of water in the drainage ditch 2, prevent water accumulation in the drainage ditch 2, and effectively prevent excessive water accumulation in the drainage ditch 2 from affecting the stability of the slope of the internal spoil heap.

[0030] To further optimize the technical solution, the drainage system provided in this embodiment of the application also includes: a water guide pipe 4, which is laid on the upper surface of the backfill layer 3, and the laying direction of the water guide pipe 4 is consistent with the extension direction of the drainage ditch 2. The water guide pipe 4 guides the water in the drainage ditch 2, ensuring that the water can be discharged more smoothly and quickly, thereby improving drainage efficiency.

[0031] To facilitate the rapid and convenient installation of the waterproof covering layer 1 on the slope surface of the internal spoil heap, while also ensuring its waterproofing effect on the slope, the waterproof covering layer 1 provided in this application includes multiple longitudinally parallel composite geomembranes, with an overlap width of more than 10 cm between adjacent geomembranes. This overlap width prevents rainwater from flowing into the slope through the gaps between adjacent composite geomembranes, ensuring both rapid installation of the waterproof covering layer 1 and its effective waterproofing.

[0032] To further optimize the technical solution, the composite geomembrane in the drainage system provided in this application embodiment includes a polyethylene membrane and a geotextile. In the technical solution provided in this application embodiment, the polyethylene membrane and geotextile achieve functional complementarity and synergistic effect, specifically addressing the shortcomings of insufficient drainage and protection performance of single geotextile materials.

[0033] On the one hand, geotextile and polyethylene membrane form a dual barrier of seepage prevention and protection. The polyethylene membrane has an extremely low permeability coefficient, which can effectively block the seepage path of water and avoid problems such as foundation softening and soil erosion caused by groundwater and surface water leakage. The outer geotextile can disperse external forces and resist puncture by sharp objects, protect the polyethylene membrane from construction or environmental friction damage, extend the service life of seepage prevention, and solve the pain points of poor puncture resistance and easy failure of single polyethylene membrane. The two work together to improve the seepage prevention reliability of composite geomembrane.

[0034] On the other hand, the composite structure formed by geotextile and polyethylene membrane can effectively improve the drainage and mechanical stability of the composite geomembrane, better adapting to complex slope environments while also providing filtration and drainage functions. It can trap soil particles and prevent siltation, while also quickly discharging small amounts of seeping water, reducing pore water pressure. The combination of the two forms an integral load-bearing structure, enhancing the material's tensile strength, tear strength, and deformation resistance. It can adapt to complex terrains such as foundation settlement and slope undulations, avoiding damage caused by local stress concentration, ensuring the long-term stable operation of the seepage prevention and drainage system, and exhibiting excellent stability.

[0035] While ensuring good water-proofing effect of the composite geomembrane, this application also considers the design requirements of low cost and easy installation of the composite geomembrane. In the technical solution provided in this application embodiment, the thickness of the polyethylene film is greater than 1.0 mm, and the specification of the geotextile is greater than 150 g / m². 2 .

[0036] In the drainage system provided in this embodiment, the drainage ditch 2 is trapezoidal, wider at the top and narrower at the bottom. The top width of the drainage ditch 2 is 1.0-1.5 meters, the bottom width is 0.5-0.8 meters, and the depth is 0.8-1.2 meters. This top-wide, bottom-narrow structure allows for rapid collection of water from the slope of the internal spoil heap, expanding the catchment area and preventing rainwater runoff from eroding the slope. Simultaneously, the narrowed bottom reduces the water flow cross-section, increasing the flow velocity, reducing siltation, and solving drainage problems. Furthermore, based on the required drainage volume, the top width of the drainage ditch 2 is limited to 1.0-1.5 meters, and the bottom width is limited to 0.5-0.8 meters. Further, to ensure effective water storage capacity and meet drainage needs in extreme weather conditions such as sudden rainfall during the rainy season, the bottom width of the drainage ditch 2 is 0.5-0.8 meters, effectively preventing water overflow. By limiting the structure and specific dimensions of drainage ditch 2, both the water collection and drainage efficiency of drainage ditch 2 are improved.

[0037] Meanwhile, the trapezoidal structure, narrower at the top and wider at the bottom, achieves both structural stability and practicality. Specifically, the trapezoidal structure distributes forces evenly, with gentle side slopes, effectively dispersing the soil pressure and water flow impact on drainage ditch 2, preventing ditch wall collapse, and adapting to the foundation conditions of loose materials in the internal spoil heap. By further limiting the dimensions of drainage ditch 2, a balance is achieved between drainage capacity and construction costs, meeting the water collection needs of the soft rock spoil heap while facilitating on-site excavation, lining construction, and subsequent dredging and maintenance, ensuring the long-term stable operation of the drainage system and providing a solid defense for the slope stability of the internal spoil heap.

[0038] To further optimize the technical solution and improve the drainage speed of the drainage ditch 2 and prevent water accumulation at the bottom of the drainage ditch 2, the drainage system provided in this application embodiment has a slope at the bottom of the drainage ditch 2, with the slope angle being 2‰-5‰.

[0039] To balance the stability, drainage effect, and ease of construction of backfill layer 3, the technical solution provided in this application embodiment includes backfill layer 3 comprising: layered rubble, with a single layer thickness of 30-50 cm, a rubble particle size of 20-40 cm, and a rubble compressive strength of 25 MPa. This enhances both load-bearing capacity and resistance to deformation. Specifically, by limiting the compressive strength of the rubble, the high hardness and stability of the rubble improve the overall load-bearing capacity of backfill layer 3, making it suitable for scenarios with high strength requirements, such as soft rock open-pit mine spoil heaps and foundation backfilling. Simultaneously, the 20-40 cm particle size combined with the 30-50 cm layered filling thickness reduces interlayer voids, forming a dense whole after compaction, effectively resisting upper loads and foundation settlement, and preventing cracking and instability of the upper structure caused by uneven deformation of backfill layer 3. The natural pores between the rubble stones can form efficient drainage channels, which can quickly drain the seepage water in backfill layer 3, reduce pore water pressure, and reduce the softening effect of groundwater on backfill layer 3. During construction, the layered filling method facilitates on-site compaction. The precise particle size and thickness parameters balance the density and construction efficiency, avoiding the problem of poor drainage caused by excessively large particle size or too small particle size, and ensuring that backfill layer 3 can play a stable role in bearing and drainage for a long time.

[0040] To further optimize the technical solution and improve the drainage effect of the water pipe 4, in the technical solution provided in this application embodiment, the diameter of the water pipe 4 is 100-150 mm, the water pipe 4 is provided with multiple water permeable holes with a diameter of 6 mm, and the spacing between adjacent water permeable holes is 12 mm.

[0041] Please see here. Figure 2 In order to provide a more complete description of the drainage system for a spoil heap in a soft rock open-pit mine provided in this application embodiment, the laying process of the drainage system will be further described below.

[0042] Step 1: Pre-treatment. Thoroughly clean the flat slope of the internal spoil heap, removing weeds, gravel, loose soil, and other debris. Level any protruding parts of the slope to ensure a smooth surface and provide a good foundation for the laying of the geomembrane.

[0043] Step 2: Lay the composite geomembrane on the leveled slope surface, starting from the top and gradually working towards the bottom, ensuring the geomembrane adheres tightly to the slope surface without wrinkles or air pockets. Leave a 10cm overlap between adjacent geomembranes to ensure a secure and sealed connection.

[0044] Step 3: Based on the designed dimensions and location, excavate drainage ditches along the extension direction of the inner spoil heap slope. During the excavation process, an excavator is used for preliminary excavation, and then the ditch walls and bottom are manually trimmed to ensure that the cross-sectional dimensions of the ditch meet the requirements and that the bottom slope is uniform, reaching the designed slope of 3‰.

[0045] Step 4: Backfill the drainage ditch with rubble. Select qualified rubble with a particle size of 20-40cm and a compressive strength of 25MPa. Backfill in layers of 40cm thickness. After each layer, use a vibratory tamper to compact the rubble, ensuring a tight bond between the rubble and improving the integrity and permeability of the rubble backfill layer.

[0046] Step 5: After the rubble backfill layer is compacted, lay stainless steel drainage pipes on top of it. The drainage pipes are laid in the same direction as the longitudinal drainage ditch, and adjacent drainage pipes are connected by welding to prevent leakage.

[0047] After the drainage system is laid on the slope surface, when there is precipitation or seepage in the inner spoil heap, the geomembrane prevents water from seeping into the inner spoil heap. Instead, the water flows along the slope into the longitudinal drainage ditch. Water entering the longitudinal drainage ditch flows quickly under the action of the rubble backfill layer, preventing accumulation within the ditch. Simultaneously, the drainage pipes collect the water flow through permeable holes in the pipe walls and guide the water out along the longitudinal drainage ditch, thus achieving the drainage purpose of the inner spoil heap.

[0048] From the above technical solutions, it can be concluded that the drainage system for spoil heaps in soft rock open-pit mines provided in this application has the following advantages: First, covering the slope with geomembrane can effectively prevent slope seepage water from entering the internal spoil heap, reduce the amount of water entering the internal spoil heap, and reduce the risk of soil moisture content rising.

[0049] Secondly, the drainage ditch set at the bottom of the slope provides a channel for water to drain out, and combined with the slope of the ditch bottom, it is conducive to the natural flow of water.

[0050] Third, the rubble backfill in the drainage ditch can improve the permeability of the ditch, accelerate the flow of water, prevent water from accumulating in the ditch, and prevent water accumulation in the ditch from having an adverse effect on the ditch wall and the slope of the inner spoil heap.

[0051] Fourth, the drainage pipes laid on top of the rubble can guide the water flow, allowing the water to drain more smoothly and quickly, further improving drainage efficiency.

[0052] The entire drainage system has a simple structure, is easy to construct, and has a low cost. It can adapt to the environment of soft rock open mines with abundant water and poor soil permeability, effectively ensuring the slope stability of the internal spoil heap and reducing the occurrence of safety accidents.

[0053] In summary, this application provides a drainage system for an internal spoil heap in a soft rock open-pit mine, comprising: a waterproof covering layer and a drainage ditch; the waterproof covering layer covers the slope surface of the internal spoil heap, and the drainage ditch is located at the bottom of the slope of the internal spoil heap. In the technical solution provided by this application, the waterproof covering layer on the slope surface can effectively prevent seepage water from entering the internal spoil heap, reducing the amount of external water entering the internal spoil heap and avoiding potential risks due to increased moisture content; simultaneously, the drainage ditch provides an outlet channel, accelerating the flow of accumulated water, preventing water accumulation at the bottom of the slope, and preventing water accumulation from affecting the slope stability of the internal spoil heap. This solves the technical defects of existing internal spoil heaps, such as poor drainage and inability to guarantee slope stability.

[0054] The technical features of the embodiments described above can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. Furthermore, other implementation methods can be derived from the above embodiments, allowing for structural and logical substitutions and changes without departing from the scope of this disclosure.

[0055] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A drainage system for a spoil heap in a soft rock open-pit mine, characterized in that, The drainage system includes: a waterproof covering layer and a drainage ditch; the waterproof covering layer covers the slope surface of the inner spoil heap, and the drainage ditch is located at the bottom of the slope of the inner spoil heap.

2. The drainage system according to claim 1, characterized in that, The drainage system further includes a backfill layer, which is disposed inside the drainage ditch.

3. The drainage system according to claim 2, characterized in that, The drainage system further includes a water guide pipe, which is laid on the upper surface of the backfill layer, and the laying direction of the water guide pipe is consistent with the extension direction of the drainage ditch.

4. The drainage system according to any one of claims 1 to 3, characterized in that, The waterproof covering layer includes: multiple longitudinally parallel composite geomembranes, with an overlap width of more than 10 centimeters between adjacent geomembranes.

5. The drainage system according to claim 4, characterized in that, The composite geomembrane includes: a polyethylene film and a geotextile.

6. The drainage system according to claim 5, characterized in that, The polyethylene film has a thickness greater than 1.0 mm, and the geotextile has a specification greater than 150 g / m². 2 .

7. The drainage system according to any one of claims 1 to 3, characterized in that, The drainage ditch is trapezoidal, wider at the top and narrower at the bottom. The top width of the drainage ditch is 1.0-1.5 meters, the bottom width is 0.5-0.8 meters, and the depth is 0.8-1.2 meters.

8. The drainage system according to claim 7, characterized in that, The bottom of the drainage ditch has a slope, and the angle of the slope is 2‰-5‰.

9. The drainage system according to claim 3, characterized in that, The backfill layer comprises: layered rubble, with a single layer of rubble having a thickness of 30-50 cm, a particle size of 20-40 cm, and a compressive strength of 25 MPa.

10. The drainage system according to claim 9, characterized in that, The diameter of the water guide pipe is 100-150 mm, and the water guide pipe is provided with multiple water permeable holes with a diameter of 6 mm, and the distance between adjacent water permeable holes is 12 mm.

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