CN220644501U - Plugging and drainage device for karst depression bottom water falling hole - Google Patents

Abstract

The application discloses a shutoff drainage device for karst depression bottom hole that falls into water, including the arcuation covering body, the arcuation covering body includes planar bottom surface and smooth cambered surface form's upper surface, the bottom surface of arcuation covering body covers the entrance to a cave that falls into water, the bearing capacity of arcuation covering body has been strengthened to the upper surface of smooth cambered surface form, be provided with horizontal drain pipe in arcuation covering body inside, vertical drain pipe, go up the wash port and drain hole down, the drainage demand when having satisfied the karst depression and deposited the material sediment body, shutoff drainage device in this application still has the hole that falls into water packing body that has the water permeability, the stability of foundation bearing capacity has been improved again under the prerequisite of having solved the natural drainage of place has been guaranteed to fall into water, can satisfy the bearing capacity requirement and the drainage requirement of great construction material and abandonment sediment storage place, the shutoff drainage device simple structure in this application has improved the fail safe nature of building relevant construction place in the karst depression area.

Description

Plugging and drainage device for karst depression bottom water falling hole

Technical Field

The application relates to the technical field of water conservancy and hydropower, in particular to a plugging and drainage device for a karst depression bottom water falling hole.

Background

At present, pumped storage power stations are built widely in all regions of the country, and in southwest regions of China, mountainous terrains have large fall and rich water resources, and have excellent conditions for building the pumped storage power stations. However, natural caverns such as karst downholes in southwest mountain areas are widely developed, and the existence of the caverns can generate serious obstruction effect and potential safety hazard to engineering construction. In the construction process of the water conservancy and hydropower engineering, a low-lying or gentle terrain close to the warehouse sites of the upper warehouse and the lower warehouse can be selected as near as possible as a slag field for storing construction filling materials or excavating waste materials in the construction process. However, the method is suitable for building the complicated geological conditions such as the large slag field and the like which are sometimes inevitably encountered in the water falling cave. When the sites are used as larger slag fields for storing construction materials or stacking construction waste slag, two basic problems are generally faced: firstly, how to perform plugging treatment on a vertical cave so as to ensure the foundation bearing safety of a site; and how to solve the problem of self-drainage of the field. Therefore, how to provide a plugging and draining device and a method for the bottom water falling hole of a karst depression with simple and feasible and high economic applicability is a problem to be solved urgently by related professionals.

Disclosure of Invention

To the defect that exists among the prior art, this application provides a shutoff drainage device that is used for karst depression bottom to fall into water hole to when solving among the prior art and building the material sediment stock dump in the karst depression district that underground cave is developed, the potential safety hazard that surface underground cave such as falling into water hole brought and engineering place self drainage problem.

In order to achieve the above purpose, the present application provides the following technical solutions: the utility model provides a shutoff drainage device for karst depression bottom hole of falling into water, includes the arcuation covering body, the arcuation covering body includes bottom surface and upper surface, the bottom surface is the plane, the upper surface is smooth cambered surface, and the upper surface links to each other with the bottom surface of arcuation covering body sets up on the entrance to a hole of falling into water, the entrance to a hole of falling into water is covered to the bottom surface of arcuation covering body, is provided with horizontal drain pipe in arcuation covering body inside, horizontal drain pipe level runs through the arcuation covering body, is provided with the vertical drain pipe with horizontal drain pipe intercommunication in arcuation covering body inside, vertical drain pipe runs through the bottom surface of arcuation covering body, and the export of vertical drain pipe sets up in the hole of falling into water in the hole, a plurality of upper drain holes set up in the inside of arcuation covering body about the axis symmetry of arcuation covering body, the export setting of upper drain hole is in the upper surface of horizontal drain pipe.

In one embodiment, a plurality of lower drain holes are arranged between the transverse drain pipe and the bottom surface, inlets of the lower drain holes are arranged on the lower surface of the transverse drain pipe, outlets of the lower drain holes are arranged on the bottom surface of the arc-shaped cover body, and the outlets of the lower drain holes are positioned in the range of the opening of the downpipe.

In one embodiment, the distance between the pipe axis of the transverse drain pipe and the bottom surface of the arc-shaped cover body is 0.15-0.25 times of the maximum distance between the upper surface of the arc-shaped cover body and the bottom surface of the arc-shaped cover body, the vertical drain pipe is positioned on the central axis of the arc-shaped cover body, and the lower drain holes are symmetrically arranged about the central axis of the arc-shaped cover body.

In one embodiment, the hole axis of the upper drain hole is at an angle of not less than 30 ° to the horizontal ground surface, and the hole axis of the lower drain hole is at an angle of 90 ° to the horizontal ground surface.

In one embodiment, the foundation backfill body is arranged above the arc-shaped covering body and comprises a mesh layer, a mesh protection layer, a soil and stone residue protection layer and a massive stone layer, wherein the mesh layer comprises a plurality of meshes paved on the upper surface of the arc-shaped covering body, the mesh protection layer is paved on the mesh layer, the soil and stone residue protection layer is paved on the mesh protection layer, the massive stone layer is paved on the soil and stone residue protection layer, and the soil and stone residue protection layer is paved on the upper surface of the massive stone layer.

In one embodiment, the height of the foundation backfill body is 1.5-3 times the maximum distance between the upper surface of the arc-shaped covering body and the bottom surface of the arc-shaped covering body.

In one embodiment, drainage culverts are arranged on the side walls of the karst depression, one part of the drainage culverts are positioned in the foundation backfill body, the other part of the drainage culverts are positioned outside the foundation backfill body, and a drainage culvert outlet is communicated and connected with the transverse drainage pipe.

In one embodiment, when the slag body is stored in the karst depression, the height of the drainage culvert inlet is 0.5-1 m higher than the height of the upper surface of the slag body, the drainage culvert outlet is arranged in the transverse drain pipe, the length of the drainage culvert entering the transverse drain pipe is not less than 2 times of the diameter of the drainage culvert, and the pipe connection part between the drainage culvert and the transverse drain pipe is in sealed waterproof connection.

In one embodiment, a plurality of grouting anchors are arranged on the bottom surface of the arc-shaped cover body, one end of each grouting anchor is inserted into surrounding rocks of the karst depression, and the other end of each grouting anchor is inserted into the arc-shaped cover body.

In one embodiment, a falling hole filling body is arranged in the falling hole, the falling hole filling body fills the falling hole, the falling hole filling body has water permeability, the falling hole filling body sequentially comprises a riprap filling layer, a block stone filling layer and a broken stone slag filling layer from a lower port of the falling hole to an upper port of the falling hole, and an outlet of the vertical drain pipe is positioned in the riprap filling layer.

A shutoff drainage device for karst depression bottom hole in falling water among this application's beneficial effect:

the utility model provides a shutoff drainage device for karst depression bottom hole that falls into water includes the arcuation covering body, and the arcuation covering body includes planar bottom surface and smooth cambered surface form upper surface, and the bottom surface of arcuation covering body covers the entrance to a cave that falls into water, and smooth cambered surface form upper surface has strengthened the bearing capacity of arcuation covering body, is provided with horizontal drain pipe, vertical drain pipe, upper drain hole and lower drain hole in arcuation covering body inside, has satisfied the drainage demand when the karst depression deposit the material sediment body, and shutoff drainage device in this application still includes the hole that falls into water filling body that has the water permeability, the hole that falls into water filling body fills up the hole that falls into water has greatly improved the foundation bearing capacity again under the prerequisite of having solved the natural drainage of place and guaranteed the stability of falling into water hole, can satisfy the bearing capacity requirement and the drainage requirement of great construction and waste sediment storage place materials. The plugging and draining device is simple in structure, improves the safety and reliability and the green environmental protection performance of construction sites related to karst low-lying areas, enlarges the site range suitable for being used as a material slag storage site, solves construction difficulties caused by existence of karst caverns such as water falling holes in the engineering construction process, reduces the difficulty of engineering investment decision and is beneficial to shortening the construction period.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered limiting the scope, and that other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of a drainage device for plugging a drain hole at the bottom of a karst depression according to an embodiment of the present application;

FIG. 2 is an enlarged schematic view of a partial section of a foundation backfill body connected to an arc-shaped cover body by a drainage culvert in an embodiment of the application;

FIG. 3 is an enlarged schematic view of a partial cross section of a water hole filler and an arc-shaped cover according to an embodiment of the present application;

fig. 4 is a schematic top view of an arc-shaped cover in an embodiment of the present application.

Reference numerals: 1-arc-shaped covering body, 2-upper drain hole, 3-vertical drain pipe, 4-horizontal drain pipe, 5-foundation backfill body, 6-falling water hole filling body, 7-drainage culvert, 8-clear foundation line, 9-drainage culvert inlet, 10-drainage culvert outlet, 11-original topography line, 12-earthwork backfill layer, 13-grouting anchor rod, 14-slag body, 15-falling water hole, 16-underground hole system, 17-rainwater, 18-net piece, 19-net piece protective layer, 20-earth-stone slag protective layer, 21-massive stone layer, 22-lower drain hole, 23-broken stone slag filling layer, 24-block stone filling layer, 25-broken stone filling layer and 26-pipe connecting part.

Detailed Description

For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. The components of the embodiments of the present application, which are generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present application, as provided in the accompanying drawings, is not intended to limit the scope of the application, as claimed, but is merely representative of selected embodiments of the application. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments herein without making any inventive effort, are intended to be within the scope of the present application.

As shown in fig. 1-4, the embodiment of the application provides a shutoff drainage device for a karst depression bottom water falling hole, which comprises an arc-shaped cover body 1, wherein the arc-shaped cover body 1 comprises a bottom surface and an upper surface, the bottom surface of the arc-shaped cover body 1 is a plane, the upper surface of the arc-shaped cover body 1 is a smooth arc surface, the upper surface of the arc-shaped cover body 1 is connected with the bottom surface of the arc-shaped cover body 1, the arc-shaped cover body 1 is arranged on the hole of the water falling hole 15, the bottom surface of the arc-shaped cover body 1 covers the hole of the water falling hole 15, a transverse drain pipe 4 is arranged inside the arc-shaped cover body 1, the transverse drain pipe 4 horizontally penetrates through the arc-shaped cover body 1, a vertical drain pipe 3 is arranged inside the arc-shaped cover body 1 and communicated with the transverse drain pipe 4, the outlet of the vertical drain pipe 3 is arranged in the hole 15, a plurality of upper drain holes 2 are symmetrically arranged inside the arc-shaped cover body 1 about the central axis of the arc-shaped cover body 1, the upper drain holes 2 are arranged on the upper surface of the arc-shaped drain pipe 2, and the upper surface of the water falling hole 2 is arranged on the surface of the arc-shaped cover body 2.

As shown in fig. 2 to 4, in order to better drain the rainwater in the lateral drain pipe 4, a plurality of lower drain holes 22 are provided between the lateral drain pipe 4 and the bottom surface of the arc-shaped cover body 1, the inlets of the lower drain holes 22 are provided on the lower surface of the lateral drain pipe 4, the outlets of the lower drain holes 22 are provided on the bottom surface of the arc-shaped cover body 1, and the outlets of the lower drain holes 22 are located within the opening range of the downpipe 15.

The distance between the pipe axis of the transverse drain pipe 4 and the bottom surface of the arc-shaped cover body 1 is 0.15-0.25 times of the maximum distance between the upper surface of the arc-shaped cover body 1 and the bottom surface of the arc-shaped cover body 1, the vertical drain pipe 3 is positioned on the central axis of the arc-shaped cover body 1, and the lower drain holes 22 are symmetrically arranged about the central axis of the arc-shaped cover body 1.

The arc-shaped cover body 1 can improve the bearing capacity of the cover body 1, in order to strengthen the bearing capacity of the arc-shaped cover body 1, in the embodiment, the arc-shaped cover body 1 is a semicircle body, the upper drain hole 2 is arranged at equal angles about the circle center of the semicircle body, the arc-shaped cover body 1 is a reinforced concrete cover body, wherein, the concrete mark, the reinforced concrete model, the arrangement of other devices and the like are checked through the bending resistance, the shearing resistance and the bearing capacity of the slag body. In this embodiment, the diameters of the upper drain hole 2 and the lower drain hole 22 are the same, and are each less than or equal to 1/10 of the diameter of the lateral drain pipe 4. In order to enable water to flow through the transverse drain pipe 4 and flow into the water falling hole 15 faster along the drain hole, the included angle between the hole axis of the upper drain hole 2 and the horizontal ground surface is not smaller than 30 degrees, and the included angle between the hole axis of the lower drain hole 22 and the horizontal ground surface is 90 degrees. In other embodiments, the arc-shaped cover 1 may be a 1/4 sphere, or may be an arc-shaped cover 1 having a parabolic upper surface.

In order to make the stress of the arc-shaped covering body 1 more uniform and stable, as shown in fig. 1 and 2, a foundation backfill body 5 is arranged above the arc-shaped covering body 1, the foundation backfill body 5 has water permeability, and water can pass through the foundation backfill body 5 to the upper drain hole 2. The foundation backfill body 5 comprises a mesh layer 18, a mesh protective layer 19, an earth and stone slag protective layer 20 and a massive stone layer 21. The mesh layer 18 comprises a plurality of meshes paved on the upper surface of the arc-shaped cover body 1, the thickness of the mesh layer 18 is not less than 20cm, the mesh consists of reinforcing steel bars, the diameter of the reinforcing steel bars is not more than 20mm, and the mesh layer 18 can prevent sundries from blocking the water drain holes. A mesh protection layer 19 is laid on the mesh layer 18 to protect the mesh 18, and the mesh protection layer 19 is geotextile or asphalt felt. An earth and stone residue protective layer 20 is laid on the mesh protective layer 19 to protect the mesh protective layer 19, and a massive stone layer 21 is laid on the earth and stone residue protective layer 20, so that the foundation backfill body 5 has water permeability.

When the slag body 14 is stored in a karst depression, in order to prevent slag in the slag body 14 from falling into the massive stone layer 21, an earth-rock slag protective layer 20 is laid on the upper surface of the massive stone layer 21. The soil-stone slag protection layer 20 and the massive stone layer 21 in the foundation backfill body 5 are compacted, the thickness proportion of the soil-stone slag protection layer and the massive stone layer is determined according to the actual engineering condition, and in principle, the foundation backfill body 5 meets the foundation bearing capacity and simultaneously ensures the drainage requirements of the upper drainage hole 2 and the lower drainage hole 22 in the arc-shaped cover body 1. The height of the foundation backfill body 5 is 1.5-3 times of the maximum distance between the upper surface of the arc-shaped cover body 1 and the bottom surface of the arc-shaped cover body 1.

In order to better drain rainwater in a karst depression, a drainage culvert 7 is arranged on the side wall of the karst depression, a part of the drainage culvert 7 is positioned in the foundation backfill body 5, a part of the drainage culvert 7 is positioned outside the foundation backfill body 5, a drainage culvert outlet 10 is communicated with the transverse drain pipe 4, and when the karst depression stores a slag body 14, as shown in fig. 1, the height of a drainage culvert inlet 9 is higher than the height of the upper surface of the slag body 14. In this embodiment, the height of the drainage culvert inlet 9 is 0.5-1 meter higher than the height of the upper surface of the slag body 14, the drainage culvert outlet 10 is arranged in the transverse drain pipe 4, the length of the drainage culvert 7 entering the transverse drain pipe 4 is not less than 2 times the diameter of the drainage culvert 7, and the pipe connection part 26 between the drainage culvert 7 and the transverse drain pipe 4 is in sealed waterproof connection. The vertical drain pipe 3 and the horizontal drain pipe 4 are cast iron pipes, so that the service life of the drain pipe is prolonged.

In order to enhance the stability of the arc-shaped cover body 1 and the drainage culvert 7, a clear base line 8 is arranged on the inner wall of the karst depression, the clear base line 8 is at a certain distance from the original topographic line 11, and the arc-shaped cover body 1 and the drainage culvert 7 are arranged on the clear base line 8. In order to place the arc-shaped cover body 1 and lay the drainage culvert 7 at the opening of the water falling hole 15, the original topography line 11 needs to be extended and dug to the clear foundation line 8. An earthwork backfill layer 12 is arranged on the drainage culvert 7 outside the foundation backfill body 5, an earth and stone slag protection layer 20 is arranged on the drainage culvert 7 inside the foundation backfill body 5, and the thickness of the earthwork backfill layer 12 and the thickness of the earth and stone slag protection layer 20 are 1-2 times the diameter of the drainage culvert 7.

In order to enhance the stability of the plugging and drainage device, the included angle between the clear base line 8 near the side surface of the foundation backfill body 5 and the horizontal ground surface line ranges from 30 degrees to 50 degrees, a plurality of grouting anchor rods 13 are arranged on the bottom surface of the arc-shaped covering body 1 contacted with the clear base line 8, one end of each grouting anchor rod 13 is inserted into surrounding rocks of karst depressions, and the other end of each grouting anchor rod 13 is inserted into the arc-shaped covering body 1 so as to enhance the stability strength of the surrounding rocks near the water falling hole 15 and enhance the connection between the arc-shaped covering body 1 and the surrounding rocks.

In this embodiment, the maximum distance between the upper surface of the arc-shaped cover 1 and the bottom surface of the arc-shaped cover 1 is not smaller than 2 times the maximum value of the hole diameter of the water falling hole 15 and the drainage culvert 7, and the bottom surface diameter of the arc-shaped cover 1 is also not smaller than 2 times the maximum value of the hole diameter of the water falling hole 15 and the drainage culvert 7. The central axis of the arc-shaped cover body 1 coincides with the axis of the water falling hole 15, the diameter of the transverse drain pipe 4 is slightly larger than the diameter of the drainage culvert 7, and the diameter of the vertical drain pipe 3 is approximately equal to the diameter of the transverse drain pipe 4.

On the premise of not substantially damaging karst landforms, the requirements of bearing capacity of the foundation and foundation of the field are further ensured, and the requirements of water discharge, safety, stability, economy and applicability after hydraulic calculation of actual engineering are met. As shown in fig. 1 and 3, a drain hole filling body 6 is disposed inside the drain hole 15, the drain hole 15 is filled with the drain hole filling body 6, and the drain hole filling body 6 has water permeability. Those skilled in the art know that the lower port of the drop hole 15 is connected to the underground hole system 16 in a communicating manner, and the drop hole filler 6 sequentially comprises a riprap filling layer 25, a rock block filling layer 24 and a broken stone slag filling layer 23 from the lower port of the drop hole 15 to the upper port of the drop hole 15. The outlet of the vertical drain pipe 3 is positioned in the riprap filling layer 25, wherein the outlet of the vertical drain pipe 3 penetrates into the riprap filling layer 25 by 0.5-1.5 meters.

The riprap filling layer 25 should be filled from the bottom of the underground train 16 and a certain space is reserved near the height position of the outlet end of the vertical drain pipe 3 so that the outlet end of the vertical drain pipe 3 can smoothly go deep into the riprap filling layer 25. The upper surface of the crushed stone slag filling layer 23 is flush with the bottom surface of the arc-shaped cover body 1, and the crushed stone slag filling layer 23 and the block stone filling layer 24 should both provide proper space for the insertion of the vertical drain pipe 3 during filling. The filling ratio of the riprap filling layer 25, the block stone filling layer 24 and the broken stone slag filling layer 23 is determined according to the actual engineering drainage requirements, but in principle, the basic ratio of the thickest riprap filling layer 25, the 24 times of the block stone filling layer and the thinnest broken stone slag filling layer 23 is maintained.

The specific dimensions of the vertical drain pipe 3, the horizontal drain pipe 4, the drain culvert 7, the upper drain hole 2 and the lower drain hole 22, the specific proportional thicknesses among different backfill layers in the foundation backfill body 5 and the specific proportional thicknesses among different filling layers of the water falling hole filling body 6 are all determined through actual hydraulic calculation so as to meet the water quantity drainage requirements of actual different projects.

As shown in fig. 1, the rainwater 17 sequentially passes through the drainage culvert inlet 9, the drainage culvert inlet 10, the transverse drain pipe 4, the vertical drain pipe 3 and the lower drain hole 22, and finally is discharged to the underground tunnel system 16 through the filtration of the downpipe filling body 6 inside the downpipe 15. The water or gas in the slag body 14 permeates from the foundation backfill body 5 to the upper drain hole 2 to be discharged to the transverse drain pipe 4, finally flows into the water falling hole 15 through the vertical drain pipe 3, is filtered by the water falling hole filling body 6 and is discharged to the underground hole system 16.

The embodiment of the application also provides a plugging and draining method for a water falling hole at the bottom of a karst depression, which comprises the following steps:

s1, surveying and investigation are carried out on a water falling hole 15, the plane size and depth of a hole opening of the water falling hole 15 are counted, relevant hydraulic calculation is carried out to determine the size of a drainage culvert 7, and the arc-shaped cover body 1 is designed;

s2, carrying out certain digging and base cleaning on the area near the opening of the water falling hole 15 to a base line 8;

s3, sequentially filling a riprap filling layer 25, a block stone filling layer 24 and a broken stone slag filling layer 23 into the water falling hole 15 from bottom to top;

s4, pouring an arc-shaped cover body 1;

s5, cleaning the irregularly undisturbed topographic line 11 of the karst depression to a flat clean base line 8 and paving a drainage culvert 7 on the clean base line;

s6, paving a foundation backfill body 5 on the surface of the arc-shaped covering body 1, and simultaneously arranging a soil and stone backfill layer 12 on the drainage culvert 7.

In step S2, after the foundation is excavated, the grouting anchor 13 is set on the surface of the foundation near the hole of the water falling hole 15.

The foregoing description is only of the preferred embodiments of the present application and is not intended to limit the same, but rather, various modifications and variations may be made by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims (10)

1. The utility model provides a shutoff drainage device for karst depression bottom hole of falling into water, its characterized in that, including the arcuation covering body, the arcuation covering body includes bottom surface and upper surface, the bottom surface is the plane, the upper surface is smooth cambered surface, and the upper surface links to each other with the bottom surface of arcuation covering body sets up on the entrance to a cave of falling into water, the entrance to a cave of falling into water is covered to the bottom surface of arcuation covering body, is provided with horizontal drain pipe in arcuation covering body inside, horizontal drain pipe level runs through arcuation covering body, is provided with the vertical drain pipe with horizontal drain pipe intercommunication in arcuation covering body inside, the bottom surface of arcuation covering body is run through to vertical drain pipe, and the export setting of vertical drain pipe is in the hole of falling into water in the hole, a plurality of upper drain holes set up in the inside of arcuation covering body about the axis symmetry of arcuation covering body, the export setting of upper drain hole is at horizontal upper surface of drain pipe.

2. The plugging and draining device for the water falling hole at the bottom of the karst depression according to claim 1, wherein a plurality of lower draining holes are arranged between the transverse draining pipe and the bottom surface, inlets of the lower draining holes are arranged on the lower surface of the transverse draining pipe, outlets of the lower draining holes are arranged on the bottom surface of the arc-shaped covering body, and outlets of the lower draining holes are positioned in the range of the opening of the water falling hole.

3. The plugging and draining device for the water falling hole at the bottom of the karst depression according to claim 2, wherein the distance between the pipe axis of the transverse drain pipe and the bottom surface of the arc-shaped cover body is 0.15-0.25 times the maximum distance between the upper surface of the arc-shaped cover body and the bottom surface of the arc-shaped cover body, the vertical drain pipe is positioned on the central axis of the arc-shaped cover body, and the lower drain holes are symmetrically arranged about the central axis of the arc-shaped cover body.

4. The plugging drainage device for a karst depression bottom water falling hole according to claim 2, wherein an angle between a hole axis of the upper drainage hole and a horizontal ground surface is not less than 30 °, and an angle between a hole axis of the lower drainage hole and a horizontal ground surface is 90 °.

5. The plugging and drainage device for the water falling hole at the bottom of the karst depression according to claim 1, wherein a foundation backfill body is arranged above the arc-shaped covering body, the foundation backfill body comprises a mesh layer, a mesh protection layer, a soil and stone residue protection layer and a massive stone layer, the mesh layer comprises a plurality of meshes paved on the upper surface of the arc-shaped covering body, the mesh protection layer is paved on the mesh layer, the soil and stone residue protection layer is paved on the mesh protection layer, the massive stone layer is paved on the soil and stone residue protection layer, and the soil and stone residue protection layer is paved on the upper surface of the massive stone layer.

6. The plugging and drainage device for karst depression bottom drop-in holes according to claim 5, wherein the height of the foundation backfill body is 1.5-3 times the maximum distance between the upper surface of the arc-shaped covering body and the bottom surface of the arc-shaped covering body.

7. The plugging and draining device for the water falling hole at the bottom of the karst depression according to claim 5, wherein a drainage culvert is arranged on the side wall of the karst depression, a part of the drainage culvert is positioned in the foundation backfill body, a part of the drainage culvert is positioned outside the foundation backfill body, and a drainage culvert outlet is communicated and connected with the transverse drain pipe.

8. The plugging and draining device for the water falling hole at the bottom of the karst depression according to claim 7, wherein when the karst depression is used for storing a slag body, the height of the drainage culvert inlet is 0.5-1 m higher than the height of the upper surface of the slag body, the drainage culvert outlet is arranged in the transverse drain pipe, the length of the drainage culvert entering the transverse drain pipe is not less than 2 times the diameter of the drainage culvert, and the pipe connection part between the drainage culvert and the transverse drain pipe is in sealed waterproof connection.

9. The plugging and drainage device for the water falling hole at the bottom of the karst depression according to claim 1, wherein a plurality of grouting anchors are arranged on the bottom surface of the arc-shaped covering body, one end of each grouting anchor is inserted into surrounding rocks of the karst depression, and the other end of each grouting anchor is inserted into the arc-shaped covering body.

10. The plugging and draining device for the water falling hole at the bottom of the karst depression according to claim 1, wherein a water falling hole filling body is arranged in the water falling hole, the water falling hole filling body fills the water falling hole, the water falling hole filling body has water permeability, the water falling hole filling body sequentially comprises a rubble filling layer, a block stone filling layer and a rubble slag filling layer from a lower port of the water falling hole to an upper port of the water falling hole, and an outlet of the vertical drain pipe is positioned in the rubble filling layer.