Intelligent system for vertical pressure-relief well of tailings dam

Abstract

The utility model provides a kind of tailing pond dam vertical pressure-relief well intelligent system, when earthquake comes, due to water pressure rise, a part of water will enter into pressure-relief well, so that water level in pressure-relief well rises, when water pressure in pressure-relief well detects and exceeds threshold value, the utility model carries out active pumping to water pipe layering and thereby carries out layering pressure relief to groundwater, to prevent dam instability and cause accident. Technical scheme: including the outer water seepage pipe that is punched into tailing pond dam, the lower end of outer water seepage pipe is placed below wetting line, a plurality of outer water seepage holes are opened on outer water seepage pipe, water pressure sensor is installed at the bottom of outer water seepage pipe, a plurality of water seepage nets are vertically and spacedly arranged in outer water seepage pipe, water pump is installed below each water seepage net and above the uppermost water seepage net, water pump is connected to the outside of water seepage pipe through drain pipe, water pump and water pressure sensor are connected in electric control box placed outside water seepage pipe.

Description

Technical Field

[0001] This utility model relates to the field of tailings dam safety technology, and in particular to an intelligent system for vertical pressure relief wells in tailings dams. Background Technology

[0002] The phreatic line is the free water level formed within the dam body as water seeps downstream from the reservoir. The phreatic line is a critical element for tailings dams, and its depth directly impacts dam stability. Therefore, the location of the phreatic line must be considered in studying the seepage stability of the dam, as it is indispensable for dam stability analysis.

[0003] Guo Tingting, Zhao Zhouneng, et al. published "Analysis of the Disaster-Causing Mechanism and Prevention Strategies of Tailings Dam Accidents in my country" [J]. Chemical Minerals and Processing, 2022, 51(04): 31-34. The paper analyzes the disaster-causing mechanism of tailings dam accidents in my country, identifying seepage failure, flooding, dam instability, and earthquakes as the main influencing factors, with seepage failure and earthquakes having the greatest impact. Since groundwater lies below the phreatic line, during earthquakes, the groundwater below the phreatic line easily generates excess pore water pressure, making sandy dams prone to liquefaction. If left uncontrolled, this can lead to dam instability and the risk of serious accidents. Utility Model Content

[0004] The purpose of this invention is to provide a safety intelligent system for vertical pressure relief wells in tailings dams. By setting up a pressure relief well system, when an earthquake occurs, some water will enter the pressure relief well due to the increased water pressure, causing the water level in the pressure relief well to rise. When the water pressure in the pressure relief well exceeds the threshold, this invention will actively pump water through the seepage pipes in layers to reduce the pressure of the groundwater in layers, thereby preventing the dam from becoming unstable and causing an accident.

[0005] To achieve the above objectives, this utility model provides the following technical solution: an intelligent system for vertical pressure relief wells in tailings dams, comprising an external seepage pipe driven into the tailings dam, the lower end of which is positioned below the phreatic line, characterized in that...

[0006] The outer seepage pipe is coaxially inserted with at least one inner seepage pipe from the outside to the inside (the diameter of the multiple inner seepage pipes decreases inwards). Multiple layers of seepage nets are vertically spaced between adjacent seepage pipes and inside the innermost inner seepage pipe. A water pump is installed below each seepage net in the innermost inner seepage pipe and above the uppermost seepage net.

[0007] The external seepage pipe is provided with external seepage holes, and the internal seepage pipe is provided with internal seepage holes. The diameter of the external seepage holes is larger than that of the internal seepage holes. A water pressure sensor is installed at the bottom of the lowest layer of the seepage net. As an example, in the case of multiple internal seepage pipes, the internal seepage holes on the internal seepage pipes that are successively smaller as they move inward.

[0008] The water pump is connected to the outside of the seepage pipe through a drain pipe, and the water pump and water pressure sensor are connected in an electrical control box located outside the seepage pipe.

[0009] Each stage of the dam is equipped with an external seepage pipe, and multiple external seepage pipes are spaced apart along the longitudinal direction of each stage of the dam. Preferably, the bottom of the external seepage pipe reaches the bottom of the dam.

[0010] Preferably, the drainage pipe is wrapped with geotextile and mesh in sequence.

[0011] Preferably, a groove and rail structure is provided between two adjacent seepage pipes, allowing the inner seepage pipe to be slid into the outer seepage pipe during installation. The cooperation of the rail and groove also provides support for the inner and outer seepage pipes.

[0012] Preferably, the slide groove is composed of a stepped groove with a smaller outer diameter and a larger inner diameter, and the shape of the slide rail is adapted to the slide groove.

[0013] Preferably, the seepage pipe is composed of multiple vertical pipe sections, each pipe section is equipped with a lifting lug, and adjacent lifting lugs are connected by a pull rope. The uppermost lifting lug is fixed with a pull rope that extends outward from the seepage pipe.

[0014] Preferably, two adjacent tubes are connected together via a tube connector.

[0015] Preferably, both the external and internal seepage holes are located below the wetting line.

[0016] Preferably, an external seepage pipe is installed on each stage of the dam, and multiple external seepage pipes are spaced apart in the longitudinal direction of each stage of the dam. This longitudinal direction is the direction perpendicular to the seepage line.

[0017] Preferably, the diameter of the multi-layer internal seepage holes decreases sequentially from the outside to the inside.

[0018] This invention involves drilling a hole with a drilling rig, and then inserting the outer permeation pipe. The hole should extend to the base of the tailings dam.

[0019] The seepage pipe is wrapped in geotextile and mesh in sequence. The mesh is made of stainless steel and the geotextile is permeable geotextile.

[0020] The beneficial effects of this utility model are:

[0021] 1. The external and internal infiltration pipes form a circumferential filter with multiple rings. The water flows from the large-diameter permeable holes of the external infiltration pipe to the small infiltration holes of the internal infiltration pipe. The large holes are not easy to clog, and when the water reaches the small holes, it is filtered by the filter screen and geotextile at the large holes, making it even less prone to clogging.

[0022] 2. Water levels can be detected by water level sensors, and a surge in water level can indirectly provide important evidence of whether an earthquake is imminent. Sudden fluctuations and changes in water level can trigger water pumps to extract water from pressure relief wells.

[0023] 3. When an earthquake occurs, groundwater can easily generate excess pore water pressure, which can cause the sand and gravel at the lower end of the dam to liquefy. During the shaking process, some of the groundwater will enter the pressure relief well, causing the water level in the pressure relief well to rise. Therefore, the multi-stage pump invented in this paper can extract the groundwater in time and reduce the pressure of the groundwater.

[0024] 4. Multiple vertically installed permeable nets within the permeable pipe allow water to flow downwards from the nets as they are rapidly pumped out. This creates negative pressure within the pipe below the nets, facilitating faster accumulation of groundwater. Without these multiple permeable nets, the permeable pipe remains completely unobstructed. Even with multiple pumps, the water level at the top of the pipe drops first, allowing upper groundwater to quickly seep in, but the lower permeability remains unchanged. Under dynamic loads such as earthquakes, the pressure on the upper groundwater level decreases without corresponding pressure reduction in the lower aquifer, posing a significant risk of dam instability. Furthermore, the multi-layered permeable nets of this invention, even without pumping, maintain hydraulic contact between the water inside the pipe and the outside environment, allowing water level detection via a water level sensor. Only when the water pump is pumping water rapidly, and the seepage of the seepage net is not timely, will the water level at the bottom of the seepage net drop. This ensures good coordination between the water pump and the seepage net, allowing for simultaneous depressurization of multiple layers of groundwater.

[0025] 5. The pipe body is composed of multiple vertical sections, and each section has at least two lugs (two adjacent pipes are sealed together by a pipe connector). The lugs of the multiple pipe sections are used to string the sections together with steel wire ropes to prevent the lower section from being difficult to lift if the upper section is damaged during upward lifting. Steel wire ropes can be used to lift the pipe.

[0026] 6. If water is pumped from the lowest pump in the lower space, the surrounding groundwater will quickly seep into and replenish that section of the pipe (due to the presence of a seepage net, the water level above the seepage pipe drops more slowly, creating a negative pressure zone at the lower pumping section). Once the surrounding groundwater flows into the pipe, the water in the upper soil layer will change its seepage direction, seeping downwards into the corresponding soil layer of the pumping pipe and then into the well, thus altering the seepage field. The downward seepage force makes the soil or dam more stable and also compacts the soil. (This function is generally used after lowering the phreatic line normally; during an earthquake, all pumps are fully operational.) Attached Figure Description

[0027] To more clearly illustrate the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the external seepage pipe of this utility model installed on the tailings dam body;

[0029] Figure 2 This is a front view schematic diagram of the connection structure between the external seepage pipe and the internal seepage pipe of this utility model;

[0030] Figure 3 This is a top sectional view of the connection between the internal and external seepage pipes of this utility model;

[0031] Figure 4 This is a schematic diagram showing the two sections of the drainage pipe of this utility model connected together by a pipe connector.

[0032] Figure 5 A schematic diagram showing the installation of a permeable geotextile layer on the upper part of the perforated stainless steel plate of this utility model.

[0033] Figure 6 This is a schematic diagram of groundwater seeping into each vertical seepage pipe of this utility model (the seepage pipe is divided into multiple layers by a seepage network, and multiple water pumps are pumping water at the same time).

[0034] Figure 7 This is a top view schematic diagram of the arrangement of the external seepage pipes in this utility model.

[0035] Explanation of reference numerals in the attached drawings: 1. External seepage pipe; 2. External seepage hole; 3. Water pressure sensor; 4. Seepage net; 5. Water pump; 6. Drainage pipe; 7. Internal seepage pipe; 8. Internal seepage hole; 9. Geotextile; 10. Mesh net; 11. Slide chute; 12. Slide rail; 13. Lifting lug; 14. Pull rope; 15. Pipe body; 16. Pipe connector; 17. Immersion line; 18. Electrical control box; 19. Stainless steel plate. Specific Implementation

[0036] The following will refer to the appendix in the embodiments of this utility model. Figure 1-7 The technical solutions in the embodiments of this utility model are clearly and completely described herein. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0037] This utility model relates to an intelligent system for vertical pressure relief wells in tailings dams. Multiple holes are drilled in the initial dam and various sub-dams of the tailings dam, extending to the bottom of the dam. An external seepage pipe 1 is then inserted into these holes, containing an internal seepage pipe 7. Both the external seepage pipe 1 and the internal seepage pipe 7 are composed of multiple pipe sections 15, connected together by a pipe connector 16. To ensure the stability of the external seepage pipe 1 and the internal seepage pipe 7, a stepped groove 11 (smaller on the outside, larger on the inside) is provided in the external seepage pipe 1, and a stepped slide rail 12 is provided on the outside of the internal seepage pipe 7. The slide rail 12 and the groove 11 cooperate, interlocking the grooves and tracks of the external seepage pipe 1 and the internal seepage pipe 7, thus ensuring their stability. The lower ends of both the external seepage pipe and the internal seepage pipe are positioned below the wetting line.

[0038] In the embodiment with only an external seepage pipe 1, multiple layers of seepage nets 4 are vertically spaced inside the external seepage pipe 1. In this case, the seepage net 4 is a single piece, and its shape is adapted to the internal cavity shape of the external seepage pipe 1. In the embodiment where at least one internal seepage pipe 7 is coaxially arranged from the outside to the inside of the external seepage pipe 1, multiple layers of seepage nets 4 are still provided. Each layer of the seepage net is divided into multiple parts. Specifically, a ring-shaped seepage net connects the external seepage pipe 1 and its adjacent internal seepage pipe 7; a ring-shaped seepage net connects two connected internal seepage pipes; and a seepage net adapted to the inner diameter of the innermost internal seepage pipe is connected inside the innermost internal seepage pipe.

[0039] Multiple layers of permeable mesh 4 are vertically spaced between the external and internal permeable pipes 7, and within the internal permeable pipe 7. The external permeable pipe has external permeable holes 2, and the internal permeable pipe 7 has internal permeable holes 8. The permeable mesh 4 consists of a perforated stainless steel plate 19 and a permeable geotextile 9 covering the stainless steel plate. The permeable geotextile 9 is placed on top of the perforated stainless steel plate, enabling the permeable mesh 4 to function as a permeable material. Both the external and internal permeable pipes 1 and 7 are wrapped from the inside out with geotextile 9 and mesh 10. The mesh 10 not only serves a filtering function but also provides support and protection for the geotextile 9 layers. The permeable holes of the permeable pipes are located below the phreatic line 17 to allow groundwater to infiltrate. The permeable mesh 4 is also located below the phreatic line 17. When only the external permeable pipe 1 is present, the permeable mesh 4 is detachably fixed inside the external permeable pipe 1 with screws. The permeable mesh 4 has through holes for drainage pipes and electrical lines to pass through. In another embodiment, when an internal seepage pipe 7 is installed inside the external seepage pipe 1, each layer of the external seepage net 4 has two parts: one part is a disc-shaped part installed inside the internal seepage pipe 7, and the other part is a ring-shaped part installed between the internal seepage pipe 7 and the external seepage pipe 1. Both parts have through holes and are detachably fixed by screws. The internal disc-shaped through holes are used for drainage pipes and lines to pass through, and the external ring-shaped through holes are used for pull ropes 14 to pass through. Water seeps into the seepage pipe sequentially from the mesh 10, geotextile 9, and seepage holes.

[0040] Pumps 5 are installed in the space below the seepage net 4 and above the uppermost seepage net 4. The pumps 5 are installed in the innermost seepage pipe 7. The pumps 5 can pump water out of the seepage pipe through the drainage pipe. A water pressure sensor 3 is installed at the bottom of the lowermost seepage net 4. When an earthquake occurs, under the action of dynamic load, the groundwater is prone to form excess pore water pressure, which can easily cause liquefaction of some sandy dams and other groundwater. During the shaking process, some groundwater enters the pressure relief well, causing the water level in the pressure relief well to rise. At this time, the multi-stage pumps 5 are used to pump out the groundwater in time to reduce the groundwater pressure. The reason for using a multi-stage seepage network 4 and multi-stage pumps 5 is that if it were a single, permeable seepage pipe with pumps 5 installed at the bottom, due to water flow, even when the lower pumps 5 start pumping, the water level at the top of the seepage pipe would drop first, while the bottom would remain full of water. The water pressure at the bottom might decrease due to the reduced water level at the top, but because the upper water level drops directly, creating a negative pressure zone, the groundwater in that area would more easily seep into the seepage pipe, while the water in the lower area would seep in more slowly. This would prevent the lower groundwater layer from effectively reducing pressure. Our intelligent system, when installed, consists of the aforementioned multi-stage pumps 5 and one or more water pressure sensors 3. The pumps 5 and water pressure sensors 3 are installed in an electrical control box 18 fixed to the upper part of the dam. A wireless transmitter can also be installed in the control box to transmit the relevant parameters of the pumps 5 and water pressure sensors 3 to a remote control center.

[0041] When an earthquake occurs, under dynamic load, some groundwater will continuously flow into the seepage pipe, causing the water level to rise. Water pressure sensor 3 detects this increase. When the water level reaches a set threshold, the controller in the electrical control box activates the multi-stage pumps 5 to begin pumping water until the water pressure drops to a reasonable range. During the pumping process, due to the multi-stage seepage network 4, when a pump 5 pumps water, the water level in that section drops rapidly. Figure 6 The diagram shows the inflow of water into the pipe body 15 of each layer. If the water seepage below the seepage net 4 cannot replenish in time, a pore will form between the water level in that section and the seepage net 4 above it, significantly reducing the pressure. This causes surrounding groundwater to rapidly flow in to fill the pore. This results in the multi-stage pump 5 simultaneously depressurizing multiple groundwater layers, greatly reducing the risk of dam failure due to earthquakes. In non-earthquake situations, because the seepage net 4 has a seepage function, the entire seepage pipe below the phreatic line 17 is filled with water and can be used as a normal piezometer to monitor the height of the phreatic line 17.

[0042] In non-earthquake situations, if the phreatic line 17 continues to rise and needs to be lowered, only the lowest pump 5 needs to be activated. This creates pores in the lowest space, allowing groundwater to flow into the seepage pipe. After some of the groundwater flows away, the upper groundwater will seep downwards. The downward seepage force during this process stabilizes the soil or dam, promoting soil compaction. Once the phreatic line 17 is lowered to a suitable position, pump 5 can be stopped.

[0043] In this utility model, the permeation pipe is composed of multiple pipe sections 15. Because the permeation pipe is relatively long, it is prone to breakage or falling during maintenance or replacement. Therefore, two symmetrical lifting lugs 13 are provided on each pipe section 15. A pull rope 14 connects two adjacent lifting lugs 13, and the uppermost lifting lug 13 is connected to a pull rope 14 with its free end outside the permeation pipe. As an embodiment, when there is only one inner permeation pipe 7, the annular permeation net between the inner permeation pipe 7 and the outer permeation pipe 1 is detachably connected to the inner permeation pipe 1, and the entire inner permeation pipe can be placed inside the outer permeation pipe. When a sliding groove 11 is provided inside the outer permeation pipe 1, and a sliding rail 12 that cooperates with the sliding groove is provided outside the inner permeation pipe, a clearance opening can be opened outside the annular permeation net to allow the sliding groove to pass smoothly through the clearance groove, ensuring that the inner permeation pipe can be smoothly placed inside the outer permeation pipe 1. As another embodiment, when multiple coaxial inner seepage pipes 7 are sequentially arranged from the outside to the inside of the outer seepage pipe 1, the diameter of the multiple inner seepage pipes 7 decreases sequentially from the outside to the inside. The annular seepage net between two adjacent inner seepage pipes can be detachably fixed to the outside of the inner seepage net located in the inner layer. The annular seepage net between the outermost inner seepage pipe and the outer seepage pipe 1 can be detachably fixed to the outermost inner seepage pipe. In use, the inner seepage pipe with the annular seepage net can be placed in the seepage pipe on its outer side in sequence. The circular seepage net of the innermost seepage pipe can be detachably fixed to the innermost seepage pipe. When a sliding groove 11 is provided on the outer seepage pipe between two adjacent seepage pipes and a sliding rail 12 is provided on the inner seepage pipe, a clearance opening can be opened on the outside of the annular seepage net so that the sliding groove can pass smoothly through the clearance groove, ensuring that the inner seepage pipe can be smoothly put into the outer seepage pipe.

[0044] If the leaking pipe breaks when pulled upwards, it can be easily removed because of the suspending rope.

[0045] The above embodiments provide examples of a single external seepage pipe 1, an external seepage pipe 1 and an internal seepage pipe 7, or an external seepage pipe and multiple internal seepage pipes. Of course, there can also be multiple internal seepage pipes 7, for example, a first internal seepage pipe 7 installed inside the external seepage pipe 1, and a second internal seepage pipe 7 installed inside the first internal seepage pipe 7. Their structural function is consistent with the interaction between the external and internal seepage pipes 1 described above. The above descriptions only depict some embodiments based on the technical solution of this utility model. Other modified embodiments based on the technical concept of this utility model are also within the protection scope of this utility model.

Claims

1. A smart system for vertical pressure relief wells in tailings dams, comprising an external seepage pipe (1) driven into the tailings dam, wherein the lower end of the external seepage pipe (1) is positioned below the wetting line (17), characterized in that, The external seepage pipe (1) has at least one internal seepage pipe (7) that passes through it coaxially from the outside to the inside. Multiple layers of seepage nets (4) are vertically spaced between adjacent seepage pipes and in the innermost internal seepage pipe (7). A water pump (5) is installed below each seepage net (4) in the innermost internal seepage pipe (7) and above the uppermost seepage net (4). The external seepage pipe is provided with an external seepage hole (2), and the internal seepage pipe (7) is provided with an internal seepage hole (8). The diameter of the external seepage hole (2) is larger than that of the internal seepage hole (8). A water pressure sensor (3) is installed at the bottom of the lowest seepage net (4). The water pump (5) is connected to the outside of the seepage pipe through the drain pipe (6), and the water pump (5) and the water pressure sensor are connected in the electrical control box (18) located outside the seepage pipe; Each dam body is equipped with an external seepage pipe (1), and multiple external seepage pipes (1) are spaced apart in the longitudinal direction of each dam body.

2. The intelligent system for vertical pressure relief wells in tailings dams according to claim 1, characterized in that, The seepage pipe is wrapped with geotextile (9) and mesh (10) in sequence.

3. The intelligent system for vertical pressure relief wells in tailings dams according to claim 2, characterized in that, A sliding groove (11) and a sliding rail (12) structure are provided between two adjacent inner and outer seepage pipes, so that during installation, the inner seepage pipe can be slid into the outer seepage pipe through the sliding rail (12) and sliding groove (11) structure.

4. The intelligent system for vertical pressure relief wells in tailings dams according to claim 3, characterized in that, The slide groove (11) is composed of a stepped groove with a smaller outer diameter and a larger inner diameter, and the slide rail (12) is adapted to the shape of the slide groove (11).

5. The intelligent system for vertical pressure relief wells in tailings dams according to claim 1, characterized in that, The seepage pipe is composed of vertical multi-section pipe (15), each section of pipe (15) is equipped with a lifting lug (13), and two adjacent lifting lugs (13) are connected by a pull rope (14). A pull rope (14) extending outward from the uppermost lifting lug (13) is fixed on it.

6. The intelligent system for vertical pressure relief wells in tailings dams according to claim 5, characterized in that, Two adjacent tubes (15) are connected together via a tube connector (16).

7. The intelligent system for vertical pressure relief wells in tailings dams according to claim 1, characterized in that, Both the external seepage hole (2) and the internal seepage hole (8) are located below the wetting line.

8. The intelligent system for vertical pressure relief wells in tailings dams according to claim 1, characterized in that, The diameter of the multi-layer internal seepage holes (8) decreases sequentially from the outside to the inside.

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