Combined precipitation and drainage system suitable for strip mine side slope upper layer stagnant water treatment

Abstract

The utility model discloses a combined dewatering and drainage system suitable for treating stagnant water on the upper layer of a strip mine side slope. An inclined drainage hole (1), a vertical drainage hole (2) and a drainage ditch (3) are combined to form the combined dewatering and drainage system. Sleeves are arranged in the inclined drainage hole (1) and the vertical drainage hole (2) within the depth of a fissure zone, a hard permeable pipe penetrates through the sleeves and extends into the inclined drainage hole (1) and the vertical drainage hole (2), and a water stop plug is arranged in an annular gap between the hard permeable pipe and the wall of the inclined drainage hole (1) and the wall of the vertical drainage hole (2). And a plurality of water permeable holes are formed in the hard water permeable pipe below the water stop plug in the vertical drainage hole (2) and the hard water permeable pipe within the water stop plug in the inclined drainage hole (1). The water pressure near the water-resisting layer is reduced through the continuous gravity drainage effect, the rainfall cost is reduced, the erosion influence of water flow on slope cracks is avoided, and the overall stability of the strip mine slope is improved.

Description

Technical Field

[0001] The utility model belongs to the field of mine slope management, and in particular relates to a combined precipitation and drainage system for stagnant water in the upper layer of a non-coal open-pit mine slope. Background Art

[0002] Groundwater in the slopes of open pit mines is usually the main or contributing factor to instability. When there is an impermeable layer in the slope and the rock mass with better permeability is located in the deeper layer, the drop in the main groundwater level will lead to the formation of an upper stagnant water zone, which will increase the pore water pressure of the slope and reduce the stability of the open pit slope. There are mature drainage methods for the upper stagnant water in the foundation pit, such as the patent No. CN114855813B that uses a water collecting pipe to actively extract the upper stagnant water in the foundation pit, but the drainage structure does not take into account the high height of the open pit slope and the long-term replenishment of the upper stagnant water by rainfall. Extracting precipitation greatly increases the drainage cost. Therefore, by guiding the upper stagnant water to the deep rock mass with better permeability or discharging it from the slope through gravity precipitation, the upper stagnant water can be effectively discharged while reducing the drainage cost.

[0003] Gravity precipitation is a commonly used drainage measure for mine slopes, mainly including drainage holes, water collection wells, drainage tunnels, etc. A single drainage method is not efficient in a complex groundwater environment, so a multi-drainage system is currently used for combined precipitation, such as the slope drainage structure with patent number CN204898695U, which can achieve the purpose of lowering the groundwater level of the slope by forming a combined drainage structure through drainage holes and drainage tunnels, but does not take into account the surface fracture zone of the slope caused by excavation unloading and blasting. When groundwater infiltrates into the fracture zone, there is a risk of softening and collapse of the fracture zone. Therefore, in order to ensure safe production in mines, there is an urgent need for a drainage method that can simultaneously lower the groundwater level of the slope and ensure the stability of the surface fracture zone of the slope. Summary of the invention

[0004] The purpose of the utility model is to provide a combined precipitation and drainage system suitable for treating stagnant water in the upper layer of an open-pit mine slope in view of the above-mentioned problems existing in the prior art.

[0005] The application scenario of the utility model is: the upper layer of the open-pit mine step slope contains a fracture zone, the open-pit mine step slope contains an impermeable layer, an upper water retention zone is formed above the impermeable layer, and below the impermeable layer is rock mass / bedrock with good permeability.

[0006] In order to achieve the above-mentioned purpose of the utility model, the utility model provides a combined precipitation and drainage system suitable for treating stagnant water in the upper layer of an open-pit mine slope, which is composed of a combination of upward-inclined drainage holes, vertical drainage holes, and drainage ditches. The upward-inclined drainage holes are arranged in two rows, one row of which is arranged from the outside to the inside and obliquely upward in a row of inclined drilled holes above the impermeable layer in the step slope of the open-pit mine, and the other row is arranged from the outside to the inside and obliquely upward in a row of inclined drilled holes above the foot of the step slope of the open-pit mine. The upward-inclined drainage holes penetrate from the slope surface of the step slope of the open-pit mine through the fracture zone and penetrate into the rear bedrock; the vertical drainage holes are arranged in three rows, two rows of which are arranged in two rows of vertical drilled holes on the top surface of the step slope of the open-pit mine, and the other row is arranged in a row of vertical drilled holes on the platform of the step slope of the open-pit mine. The vertical drainage holes penetrate from top to bottom through the upper stagnant water zone and the impermeable layer, and penetrate into the infiltration zone below the impermeable layer. In rock mass / bedrock with good properties; there are two drainage ditches, one of which is arranged on the top surface of the open-pit mine step slope outside the top row of vertical drainage holes, and the other is arranged at the foot of the open-pit mine step slope where the inclined drainage holes are located; casings are arranged in the depth of the fracture zone of the inclined drainage holes and the vertical drainage holes, and hard water-permeable pipes pass through the casings and extend into the inclined drainage holes and the vertical drainage holes. Water-stopping plugs are arranged in the annular gaps between the hard water-permeable pipes and the drainage hole walls of the inclined drainage holes and the vertical drainage holes, and multiple water-permeable holes are opened on the hard water-permeable pipes below the water-stopping plugs in the vertical drainage holes and on the hard water-permeable pipes within the water-stopping plugs in the inclined drainage holes.

[0007] After experimental research and economic analysis, the length (depth) of the inclined drainage hole is 15 to 30 meters, the upward inclination is 5 to 10 degrees, the horizontal spacing is 3 to 6 meters, the hole diameter is 90 to 110 mm, and the diameter of the internal hard permeable pipe is preferably 10 to 40 mm smaller than the diameter of the inclined drainage hole.

[0008] Research shows that the horizontal spacing of the vertical drainage holes is preferably 3 to 6 meters, the hole diameter is 200 to 250 mm, and the diameter of the internal hard water-permeable pipe is preferably 20 to 30 mm smaller than the hole diameter of the vertical drainage holes.

[0009] The size of the drainage ditch is preferably (0.5-1.2m)×(0.5-1.2m).

[0010] As a preferred embodiment of the present invention, the diameter of the hard water-permeable pipe installed in the upward inclined drainage hole is 50-100 mm.

[0011] As a preferred embodiment of the present invention, the diameter of the hard water-permeable pipe installed in the vertical drainage hole is 150-200 mm.

[0012] Furthermore, one row of the inclined drainage holes is arranged from the outside to the inside and inclined upward in a row of inclined drilled holes 0.5m above the impermeable layer in the step slope of the open-pit mine, and the other row is arranged from the outside to the inside and inclined upward in a row of inclined drilled holes 0.5m above the foot of the step slope of the open-pit mine.

[0013] In actual use, a rigid water-permeable pipe is inserted into a vertical drainage hole, and cement mortar is filled in the annular space above the water stopper to fix the rigid water-permeable pipe. Similarly, after a rigid water-permeable pipe is inserted into an upwardly inclined drainage hole, cement mortar is also filled in the annular space inside the water stopper to fix it.

[0014] The permeability coefficient of the water-proof layer described in the utility model is generally 10 -9 Up to 10 -12 m / s. Due to the low permeability, rainwater and groundwater cannot penetrate below, thus forming an upper water retention zone above it. The permeability coefficient of the rock mass / bedrock with good permeability described in the method of the utility model is generally 10 -4 Up to 10 -7 m / s, with a high permeability coefficient and good water permeability. The stagnant water in the upper layer of the open-pit mine slope is guided to the deep rock mass with good permeability or discharged outside the slope, and the continuous stability of the surface fracture zone of the slope is guaranteed, thus improving the overall stability of the open-pit mine slope.

[0015] Compared with the prior art, the utility model, a combined precipitation and drainage system suitable for treating stagnant water in the upper layer of an open-pit mine slope, adopts the above technical solution and has the following beneficial effects:

[0016] (1) By rationally arranging inclined drainage holes, vertical drainage holes and drainage ditches, an efficient combined precipitation system is formed, which effectively guides the stagnant water in the upper layer of the open-pit mine slope to the deep rock mass with good permeability or discharges it outside the slope, thereby avoiding the erosion of the slope cracks by water flow.

[0017] (2) Through the unique design of the casing, water stopper and water permeable hole position, and filling the annular space above the water stopper with M20 cement mortar, groundwater is completely prevented from infiltrating into the fracture zone. The sprayed concrete surface is used to reduce the erosion of the fracture zone and the aquiclude by external water flow, effectively reducing the collapse risk of the fracture zone area on the surface of the slope;

[0018] (3) The water pressure near the impermeable layer was reduced through continuous gravity drainage, achieving the expected precipitation effect, significantly reducing the drainage cost, reducing the pore water pressure inside the slope, and improving the overall stability of the open-pit mine slope. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the overall structure of a combined precipitation and drainage system suitable for treating stagnant water in the upper layer of an open-pit mine slope according to the utility model;

[0020] Figure 2 The utility model is a schematic diagram of a drainage hole structure designed for a combined precipitation and drainage system suitable for treating stagnant water in the upper layer of an open-pit mine slope.

[0021] The accompanying drawings are marked as follows: 1-upward inclined drainage hole; 2-vertical drainage hole; 3-drainage ditch; 4-sprayed concrete; 5-rigid permeable pipe; 6-drainage hole wall; 7-permeable hole; 8-water stopper; 9-casing. DETAILED DESCRIPTION

[0022] To better describe the present invention, a combined precipitation and drainage system suitable for treating stagnant water in the upper layer of an open-pit mine slope is further described in detail below in conjunction with the accompanying drawings.

[0023] Depend on Figure 1 The utility model is a schematic diagram of the overall structure of a combined precipitation and drainage system suitable for treating stagnant water on the upper layer of an open pit slope. Figure 2It can be seen that the utility model is a combined precipitation and drainage system suitable for treating water retention in the upper layer of the open-pit mine slope, which is composed of an inclined drainage hole 1, a vertical drainage hole 2, and a drainage ditch 3. The upper layer of the open-pit mine step slope contains a fracture zone, and the open-pit mine step slope contains an impermeable layer, and an upper layer of water retention zone is formed on the impermeable layer. The inclined drainage holes 1 are in two rows, one of which is arranged from the outside to the inside and tilted upward in a row of inclined drilled holes above the impermeable layer in the open-pit mine step slope, and the other row is arranged from the outside to the inside and tilted upward in a row of inclined drilled holes above the foot of the open-pit mine step slope. The inclined drainage holes 1 penetrate the fracture zone from the slope surface of the open-pit mine step slope to the rear bedrock; the inclined drainage holes 1 are 15 to 30 meters long, tilted upward by 5 to 10 degrees, with a horizontal spacing of 3 to 6 meters, and an aperture of 90 to 110 mm. The diameter of the hard permeable pipe 5 installed in the inclined drainage holes 1 is 50 to 100 mm. The vertical drainage holes 2 are arranged in three rows, two of which are arranged in two rows of vertical drilled holes on the top surface of the open-pit mine step slope, and the other row is arranged in a row of vertical drilled holes on the open-pit mine step slope platform. The vertical drainage holes 2 pass through the upper water retention zone and the aquiclude from top to bottom, and penetrate into the rock mass with good permeability under the aquiclude; the horizontal spacing of the vertical drainage holes 2 is 3 to 6m, the aperture is 200 to 250mm, and the internal hard water-permeable pipe 5 has a diameter of 150 to 200mm. The hard water-permeable pipe 5 is made of high-density polyethylene HDPE as the main raw material. There are two drainage ditches 3, one of which is arranged on the top surface of the open-pit mine step slope outside the top row of vertical drainage holes 2, and the other is arranged at a height of 0.5m above the foot of the slope of the open-pit mine step where the upward-inclined drainage hole 1 is located; the size of the drainage ditch 3 is (0.5-1.2m)×(0.5-1.2m), and the drainage ditch 3 is a mortar-laid stone drainage ditch, and the bottom of the ditch is plastered with mortar. The upward-inclined drainage hole 1 and the vertical drainage hole 2 are provided with casings 9 in the depth of the fracture zone, and the hard water-permeable pipe 5 passes through the casings 9 and extends into the upward-inclined drainage hole 1 and the vertical drainage hole 2. A water stopper 8 is arranged in the annular space between the hard water-permeable pipe 5 and the drainage hole wall 6 of the upward-inclined drainage hole 1 and the vertical drainage hole 2, and a plurality of water holes 7 are opened on the hard water-permeable pipe 5 below the water stopper 8 in the vertical drainage hole 2 and on the hard water-permeable pipe 5 within the water stopper 8 in the upward-inclined drainage hole 1.

[0024] The utility model discloses a combined precipitation and drainage system suitable for treating stagnant water in the upper layer of an open-pit mine slope, which is implemented by the following steps:

[0025] S1: Find out the geological conditions of the open-pit mine slope area, and according to the seepage position of the slope, after cleaning the pumice on the surface of the open-pit mine step slope, construct a sprayed concrete 4 protection surface on the surface of the open-pit mine step slope, and the sprayed concrete 4 is arranged on the surface of the step slope where the upward drainage hole 1 is located to protect the slope fracture zone and the aquiclude from the external water erosion; vertical drilling is carried out on the top surface of the open-pit mine step slope and the open-pit mine step slope platform, passing through the upper water retention zone and the aquiclude from top to bottom, and penetrating into the rock mass with good permeability under the aquiclude, and the hydrogeological parameters of the rock layers at different depths in the borehole are obtained through permeability tests, and the positions of the upper water retention zone, the aquiclude and the rock mass with good permeability under the aquiclude are found, and the exploration borehole is reserved as the vertical drainage hole 2;

[0026] S2: Determine the location and depth of the inclined drainage hole (1) and the vertical drainage hole 2 according to the lateral span of the open pit slope and the corresponding hydrogeological parameters; the vertical drainage hole 2 is arranged vertically downward; the inclined drainage hole 1 and the vertical drainage hole 2 extend beyond the surface of the open pit step slope by no less than 80 mm;

[0027] S3 vertical drainage hole layout:

[0028] ① Install casing 9 in the vertical borehole to prevent the hole from collapsing. Casing 9 passes through the fracture zone in the slope of the open-pit mine step and is located on the stable bedrock. The inner diameter of casing 9 is the same as the drainage hole diameter of the vertical drainage hole 2. Customize the hard water-permeable pipe 5 according to the depth of the fracture zone and the type of drainage hole. The water stopper 8 is arranged 0.5 to 1 m below the depth of the fracture zone. The water stopper 8 is pre-installed on the hard water-permeable pipe 5 and fits tightly. The outer diameter of the water stopper 8 is the same as the drainage hole diameter of the vertical drainage hole 2 to ensure the sealing effect of the water stopper; the hard water-permeable pipe 5 is provided with a water hole 7 below the water stopper 8, and there is no water hole above the water stopper 8;

[0029] ② Insert the rigid water-permeable pipe 5 into the vertical drainage hole 2, and fill the annular space above the water stopper 8 with M20 cement mortar to fix the rigid water-permeable pipe 5;

[0030] S4 inclined drainage hole layout:

[0031] After the shotcrete 4 in step S1 reaches the specified strength, a row of upwardly inclined drainage holes 1 is arranged from outside to inside and obliquely upward above the water-blocking layer in the open-pit mine step slope, and another row of upwardly inclined drainage holes 1 is arranged from outside to inside and obliquely upward above the foot of the open-pit mine step slope. The arrangement process of the casing 9, the water stopper 8, and the hard water-permeable pipe 5 is the same as that of step ① and ② of S3. One row of the upwardly inclined drainage holes 1 is arranged from outside to inside and obliquely upward in a row of inclined drilled holes 0.5m above the water-blocking layer in the open-pit mine step slope, and the other row is arranged from outside to inside and obliquely upward in a row of inclined drilled holes 0.5m above the foot of the open-pit mine step slope.

[0032] S5: The drainage ditches 3 are respectively arranged on the top surface of the open-pit mine step slope outside the top row of vertical drainage holes 2 and at the foot of the open-pit mine step slope where the upward drainage holes 1 are located, so as to collect the surface runoff of the open-pit mine step slope.

[0033] The utility model is a combined precipitation and drainage system suitable for treating stagnant water in the upper layer of open-pit mine slopes. It has been tested and applied in a large domestic open-pit iron mine. Through continuous gravity drainage, the water pressure near the aquiclude is reduced, the precipitation cost is reduced, and the erosion of the slope cracks by water flow is avoided, thus improving the overall stability of the open-pit mine slope.

Claims

1. A combined precipitation and drainage system suitable for treating stagnant water in the upper layer of an open-pit mine slope, characterized in that: The combined precipitation and drainage system is composed of an upward-inclined drainage hole (1), a vertical drainage hole (2), and a drainage ditch (3); the upward-inclined drainage holes (1) are arranged in two rows, one row of which is arranged from outside to inside and inclined upward in a row of inclined drilled holes above the aquiclude in the open-pit mine step slope, and the other row of which is arranged from outside to inside and inclined upward in a row of inclined drilled holes above the foot of the open-pit mine step slope. The upward-inclined drainage holes (1) penetrate the fracture zone from the slope surface of the open-pit mine step slope and penetrate into the rear bedrock; the vertical drainage holes (2) are arranged in three rows, two rows of which are arranged in two rows of vertical drilled holes on the top surface of the open-pit mine step slope, and the other row is arranged in a row of vertical drilled holes on the platform of the open-pit mine step slope. The vertical drainage holes (2) penetrate the upper water retention zone and the aquiclude from top to bottom and penetrate into the rock with good permeability below the aquiclude. The invention relates to a method for preparing a mine body; the invention relates to a mine body having two drainage ditches (3), one of which is arranged on the top surface of the open-pit mine step slope outside the top row of vertical drainage holes (2), and the other is arranged at the foot of the slope of the open-pit mine step where the upward-inclined drainage hole (1) is located; the upward-inclined drainage hole (1) and the vertical drainage hole (2) are provided with casings (9) in the depth of the fracture zone; the hard water-permeable pipe (5) passes through the casing (9) and extends into the upward-inclined drainage hole (1) and the vertical drainage hole (2); a water stopper (8) is arranged in the annular space between the hard water-permeable pipe (5) and the drainage hole wall (6) of the upward-inclined drainage hole (1) and the vertical drainage hole (2); a plurality of water-permeable holes (7) are provided on the hard water-permeable pipe (5) below the water stopper (8) in the vertical drainage hole (2) and on the hard water-permeable pipe (5) within the water stopper (8) in the upward-inclined drainage hole (1).

2. A combined precipitation and drainage system suitable for treating stagnant water in the upper layer of an open-pit mine slope as claimed in claim 1, characterized in that: The inclined drainage hole (1) is 15 to 30 meters long, inclined upward by 5 to 10 degrees, with a horizontal spacing of 3 to 6 meters and a hole diameter of 90 to 110 mm. The diameter of the internal hard water-permeable pipe (5) is 10 to 40 mm smaller than the hole diameter of the inclined drainage hole (1).

3. A combined precipitation and drainage system suitable for treating stagnant water in the upper layer of an open-pit mine slope as claimed in claim 1, characterized in that: The horizontal spacing of the vertical drainage holes (2) is 3 to 6 meters, the hole diameter is 200 to 250 mm, and the diameter of the internal hard water-permeable pipe (5) is 20 to 30 mm smaller than the hole diameter of the vertical drainage holes (2).

4. A combined precipitation and drainage system suitable for treating stagnant water in the upper layer of an open-pit mine slope as claimed in claim 1, characterized in that: The size of the drainage ditch (3) is (0.5-1.2m)×(0.5-1.2m).

5. A combined precipitation and drainage system suitable for treating stagnant water in the upper layer of an open-pit mine slope as claimed in claim 2, characterized in that: The diameter of the hard water-permeable pipe (5) installed in the upward-sloping drainage hole (1) is 50-100 mm.

6. A combined precipitation and drainage system suitable for treating stagnant water in the upper layer of an open-pit mine slope as claimed in claim 3, characterized in that: The diameter of the hard water-permeable pipe (5) installed in the vertical drainage hole (2) is 150-200 mm.

7. A combined precipitation and drainage system suitable for treating stagnant water in the upper layer of an open pit slope as claimed in claim 1, 2, 3, 4, 5 or 6, characterized in that: One row of the inclined drainage holes (1) is arranged from outside to inside and inclined upward in a row of inclined drilled holes 0.5 m above the waterproof layer in the open-pit mine step slope, and the other row is arranged from outside to inside and inclined upward in a row of inclined drilled holes 0.5 m above the foot of the open-pit mine step slope.

8. A combined precipitation and drainage system suitable for treating stagnant water in the upper layer of an open pit slope as claimed in claim 1, 2, 3, 4, 5 or 6, characterized in that: The upwardly inclined drainage hole (1) and the vertical drainage hole (2) extend beyond the surface of the open pit mine step slope by no less than 80 mm.

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