Karst depression sinkhole plugging drainage system, construction method and drainage method

Abstract

The invention provides a karst depression sinkhole plugging drainage system, a construction method and a drainage method.The plugging drainage system comprises a plurality of lower drainage pipes, concrete plugs are poured between the lower drainage pipes in a sinkhole, concrete bases are poured on the top faces of the concrete plugs and the periphery of the edge of the top end of the sinkhole, and a main drainage buried culvert is arranged at the upper end of each concrete base; part of the lower drainage pipes are communicated with a main drainage buried culvert, branch drainage buried culverts are arranged on the outer side of the main drainage buried culvert, a plurality of upper drainage pipes are arranged above the concrete base, part of the upper drainage pipes are communicated with the main drainage buried culvert, the rest of the upper drainage pipes are communicated with the corresponding lower drainage pipes, and concrete top plates are poured among the lower drainage pipes above the concrete base. Water-permeable inverted filter layers are laid on the top face of the concrete top plate and the outer sides of the water distribution and drainage buried culverts, and the water-permeable inverted filter layers are used for stacking material slag bodies. According to the method, the sinkhole can be effectively blocked, and smooth drainage of the karst depression site and the stability of the bearing capacity of the foundation of the karst depression are guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of civil engineering, and in particular relates to a karst depression sinkhole blocking and drainage system, a construction method and a drainage method. Background Art

[0002] The development and construction of large-scale infrastructure projects such as pumped storage power stations, conventional power stations, mines, roads, bridges, etc. are developing rapidly, and the treatment of waste dumps is one of the important components of engineering construction. In karst areas such as Sichuan, Chongqing, and Guizhou, natural caves such as sinkholes and karst cavities are widely developed, and flat sites are relatively scarce. Among them, sinkholes are mostly natural drainage channels for rainfall in karst depressions. The infrastructure construction projects in the region are faced with large amounts of waste, but the existence of sinkholes poses serious safety hazards to the construction of waste dumps and other buildings above the karst depressions.

[0003] At present, most projects that deal with sinkholes use large-volume concrete backfill or large-block stone backfill. The water permeability guarantee rate of large-block stone backfill is relatively low. Specifically, over time, the porosity between the backfill large blocks of stone decreases, and the water permeability guarantee rate between the backfill large blocks of stone decreases. In addition, there is a problem of large settlement and deformation when backfilling large blocks of stone. If concrete is used for direct backfilling, the original drainage function of the sinkhole will be lost, the drainage of the site will be poor, and waterlogging will occur on the site. Over time, new drainage channels may appear in the karst depression, causing karst collapse, further affecting the safety of the foundation.

[0004] Therefore, how to seal the sinkholes to ensure smooth drainage of the karst depression and the stability of the foundation bearing capacity of the karst depression is a problem that needs to be solved urgently. Summary of the invention

[0005] In view of the above-mentioned defects of the prior art, the present invention provides a karst depression sinkhole blocking and drainage system, construction method and drainage method, which can effectively block the sinkhole and ensure smooth drainage of the karst depression and the stability of the foundation bearing capacity of the karst depression.

[0006] The technical solution adopted by the present invention to solve its technical problem is:

[0007] A karst depression sinkhole blocking drainage system comprises a plurality of lower drainage pipes in the sinkhole and connected to an underground river below the sinkhole, concrete plugs are poured between the lower drainage pipes in the sinkhole, concrete bases are poured on the top surface of the concrete plugs and around the top edge of the sinkhole, the top of each lower drainage pipe extends to the top surface of the concrete base, a main drainage culvert is arranged on the upper end of the concrete base, the lower drainage pipes in the area covered by the main drainage culvert are connected to the main drainage culvert, and a main drainage culvert is arranged on the outside of the main drainage culvert. The main drainage culvert is connected to the water culvert and is inclined upward along the outside and extends to the ground surface. A plurality of upper drainage pipes are arranged above the concrete base. The upper drainage pipes in the coverage area of ​​the main drainage culvert are connected to the main drainage culvert and the remaining upper drainage pipes are connected to the corresponding lower drainage pipes. A concrete top plate is cast between the lower drainage pipes above the concrete base. The top end of each upper drainage pipe extends to the top surface of the concrete top plate. A permeable filter layer is laid on the top surface of the concrete top plate and on the outside of the sub-drainage culvert. The permeable filter layer is used for stacking slag.

[0008] Furthermore, each of the lower drainage pipes and each of the upper drainage pipes are arranged vertically, and the main drainage culvert is arranged horizontally; the top of each of the upper drainage pipes is covered with a geotextile wrap, and a steel wire filter is tied to the outside of the geotextile wrap.

[0009] Furthermore, a casting template serving as the concrete plug is provided in the sinkhole, and the casting template includes a plurality of anchor rods inserted and fixed around the side wall of the sinkhole and a horizontal flexible steel mesh fixed by the plurality of anchor rods, and a horizontal wooden template is laid on the flexible steel mesh; multiple layers of horizontal steel mesh are tied above the casting template in the sinkhole, and a plurality of dowel bars are inserted and fixed on the side wall of the sinkhole above the casting template, and each of the lower drainage pipes is arranged on the wooden template, and the arrangement position of each lower drainage pipe is determined according to the spacing between adjacent steel bars in each layer of the steel mesh. After the concrete plug is cast, the wooden template corresponding to the corresponding position of the lower drainage pipe is removed through each of the lower drainage pipes, so that each of the lower drainage pipes is connected to the underground river.

[0010] Furthermore, a drainage pipe is provided on the outside of the main drainage culvert, which is connected to the main drainage culvert and is inclined upward along the outside and extends to the surface. The upper ends of the branch drainage culvert and the drainage pipe are respectively connected to the corresponding intercepting drainage ditches on the surface.

[0011] Furthermore, there are two branch drainage culverts and two drainage pipes each; the main drainage culvert and each branch drainage culvert are formed by pouring concrete on site, the main drainage culvert includes a total concrete bottom plate, a total concrete side wall and a total concrete top arch, and the branch drainage culvert includes a sub-concrete bottom plate, a sub-concrete side wall and a sub-concrete top arch; the lower drainage pipe, the upper drainage pipe and the drainage pipe are all spliced ​​by multiple sections of prefabricated reinforced concrete pipes.

[0012] Furthermore, a plurality of drainage holes are provided on the sub-concrete top arch and the sub-concrete side walls in the sub-drainage culvert, the outer end of each drainage hole is covered with a geotextile wrap, a wire filter is tied to the outside of the geotextile wrap, a permeable filter layer is laid on the outside of the sub-concrete top arch and the sub-concrete side walls in the sub-drainage culvert and the outside of the drainage pipe, and the permeable filter layer on the outside of the drainage pipe is used for stacking slag.

[0013] Furthermore, the permeable filter layer comprises a composite body of an inner pebble layer and an outer gravel layer, and the gravel layer composite body comprises two gravel layers separated by a geotextile.

[0014] Furthermore, a plurality of reinforcing ribs are provided around the inner side surface of each of the reinforced concrete tubes, a plurality of tenons are provided around the edge of one end of each of the reinforced concrete tubes, and a plurality of grooves are provided around the edge of the other end of each of the reinforced concrete tubes, and each tenon at one end of each of the reinforced concrete tubes is clamped in a corresponding groove at the other end of an adjacent reinforced concrete tube.

[0015] A construction method for a karst depression sinkhole blocking and drainage system, used to form the karst depression sinkhole blocking and drainage system described above, comprises the following steps:

[0016] S1. Survey and record the sinkholes in the karst depression, calculate the catchment area of ​​the karst depression, the size of the sinkhole opening and the depth of the sinkhole, and design the size of the main drainage culvert, branch drainage culvert, lower drainage pipe, upper drainage pipe, concrete plug and concrete base;

[0017] S2, excavating the foundation trench and concrete base of the drainage culvert;

[0018] S3, arranging a plurality of said downpipes in the sinkhole;

[0019] S4, pouring concrete plugs between the lower drainage pipes in the sinkhole, and pouring concrete bases on the top surfaces of the concrete plugs and around the top edge of the sinkhole;

[0020] S5, firstly arranging a main drainage culvert at the upper end of the concrete base, then arranging a plurality of upper drainage pipes above the concrete base, then pouring a concrete top plate between the upper drainage pipes above the concrete base, and then arranging a sub-drainage culvert outside the main drainage culvert;

[0021] S6. A permeable filter layer is laid on the top surface of the concrete top plate and on the outside of the drainage culvert, and the permeable filter layer is used for stacking slag.

[0022] A drainage method for a karst depression sinkhole blocking drainage system adopts the above-mentioned karst depression sinkhole blocking drainage system for drainage, specifically: the internal water of the slag body enters the main drainage culvert through the permeable filter layer and the upper drainage pipes in turn, the water around the slag body enters the main drainage culvert through the branch drainage culverts, and the water entering the main drainage culvert is discharged into the underground river through the lower drainage pipes.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] The karst depression sinkhole blocking and drainage system of the present invention blocks the hole opening of the sinkhole by a concrete plug, and a concrete base is cast on the top surface of the concrete plug and around the top edge of the sinkhole so that the concrete base serves as a base for supporting the concrete top plate, and a plurality of lower drainage pipes are distributed in the concrete plug in the sinkhole, and a plurality of upper drainage pipes are distributed in the concrete top plate, and a main drainage culvert is arranged at the upper end of the concrete base, the lower drainage pipes in the area covered by the main drainage culvert are connected to the main drainage culvert, the upper drainage pipes in the area covered by the main drainage culvert are connected to the main drainage culvert, and the remaining upper drainage pipes are connected to the corresponding lower drainage pipes, and a sub-drainage culvert is provided on the outside of the main drainage culvert, which is connected to the main drainage culvert and is inclined along the upper outside and extends to the ground surface, a permeable filter layer is laid on the top surface of the concrete top plate and on the outside of the sub-drainage culvert, and the permeable filter layer is used for stacking slag bodies; in this way, the karst depression sinkhole blocking and drainage system is adopted When the system is draining, the internal water of the slag body passes through the permeable filter layer and the upper drainage pipes into the main drainage culvert in turn, the surrounding water of the slag body enters the main drainage culvert through the branch drainage culvert, and the water entering the main drainage culvert is discharged into the underground river through the lower drainage pipes. Therefore, the use of this karst depression sinkhole blocking drainage system can effectively block the sinkhole, so that the slag body can be piled on the permeable filter layer above the sinkhole, and the internal and surrounding water of the slag body can be discharged into the underground river in time to ensure the smooth drainage of the karst depression and the stability of the foundation bearing capacity of the karst depression. The permeable filter layer plays a role of permeability and anti-filtration to prevent the clay and other fine particles in the slag body from affecting the smooth drainage of the upper drainage pipes, thereby preventing the clay and other fine particles in the slag body from affecting the smooth drainage of the main drainage culvert, the branch drainage culvert and the lower drainage pipes.

[0025] In the present invention, the top of each upper drainage pipe is covered with a geotextile wrap, and a wire filter is tied to the outside of the geotextile wrap; thus, the cooperation between the geotextile wrap and the wire filter can further prevent clay and other fine particles in the slag body from entering the corresponding upper drainage pipe.

[0026] In the present invention, multiple layers of horizontal steel mesh are tied above the casting template in the sinkhole, and multiple dowels are inserted and fixed on the side wall of the sinkhole above the casting template. In this way, the anti-slip stability of the concrete plug assembly formed by the combination of the concrete plug and the concrete base can be ensured by the arrangement of multiple layers of steel mesh and multiple dowels, and the structural strength of the formed concrete plug can be ensured by the arrangement of multiple layers of steel mesh.

[0027] In the present invention, multiple drainage holes are provided on the sub-concrete top arch and the sub-concrete side wall in the sub-drainage culvert, the outer end of each drainage hole is covered with a geotextile wrap, and a wire filter is tied to the outside of the geotextile wrap. The outer side of the sub-concrete top arch and the sub-concrete side wall in the sub-drainage culvert and the outer side of the drainage pipe are all paved with a permeable filter layer, and the permeable filter layer on the outside of the drainage pipe is used to stack the slag body. In this way, the internal water collection part of the slag body can pass through the permeable filter layer and each drainage hole on the outside of the sub-drainage culvert in turn into the sub-drainage culvert. Therefore, for the discharge of the water collection inside the slag body, the permeable filter layer on the outside of the sub-drainage culvert and the arrangement of each drainage hole on the sub-drainage culvert can reduce the drainage pressure of each upper drainage pipe; and the arrangement of the geotextile wrap and the wire filter can further prevent the clay and other fine particles in the slag body from entering the corresponding drainage holes.

[0028] In the present invention, the water permeable filter layer includes an inner pebble layer and an outer gravel layer complex, and the gravel layer complex includes two gravel layers separated by geotextiles. In this way, the two gravel layers in the outer gravel layer complex and the inner pebble layer both play a water permeability role, and the geotextile in the outer gravel layer complex plays a filter effect, preventing clay and other fine particles in the slag body that is in direct contact with the gravel layer complex from entering the inner pebble layer, or preventing the ground soil that is in direct contact with the gravel layer complex from entering the inner pebble layer, thereby preventing the water permeability of the pebble layer from being affected. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the main cross-sectional structure of the karst depression sinkhole blocking and drainage system of the present invention;

[0030] Figure 2 This is a top view structural diagram of the drainage system for blocking sinkholes in karst depressions;

[0031] Figure 3 This is the cross-section diagram of the drainage culvert;

[0032] Figure 4 It is a schematic diagram of the cross-sectional structure of a drainage pipe and a water-permeable filter layer arranged around the outer side of the drainage pipe;

[0033] Figure 5 It is a schematic diagram of the splicing between two adjacent reinforced concrete pipes;

[0034] Figure 6 Schematic diagram of the structure of the sand and gravel layer complex in the permeable filter layer.

[0035] Explanation of reference numerals in the figures: 101, lower drainage pipe, 102, concrete plug, 103, concrete base, 104, main drainage culvert, 105, branch drainage culvert, 1051, branch concrete bottom plate, 1052, branch concrete side wall, 1053, branch concrete top arch, 1054, drainage hole, 106, upper drainage pipe, 107, concrete top plate, 108, geotextile wrap, 109, anchor rod, 1010, flexible steel mesh, 10 11. Wooden formwork, 1012. Steel mesh, 1013. Dowel, 1014. Drainage pipe, 1015. Intercepting ditch, 1016. Reinforced concrete pipe, 10161. Reinforcement rib, 10162. Tenon, 10163. Groove, 10171. Pebble layer, 10172. Gravel layer complex, 101721. Geotextile, 101722. Gravel layer, 2. Sinkhole, 3. Underground river, 4. Slag body. DETAILED DESCRIPTION

[0036] The specific embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. These embodiments are only used to illustrate the present invention, but not to limit the present invention.

[0037] In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0038] Furthermore, in the description of the present invention, unless otherwise specified, “plurality” means two or more.

[0039] like Figure 1 and Figure 2As shown, a karst depression sinkhole blocking drainage system includes a plurality of lower drainage pipes 101 located in the sinkhole 2 and connected to an underground river 3 below the sinkhole 2. Concrete plugs 102 are cast between the lower drainage pipes 101 in the sinkhole 2. Concrete bases 103 are cast on the top surface of the concrete plugs 102 and around the top edge of the sinkhole 2. The top of each lower drainage pipe 101 extends to the top surface of the concrete base 103. A main drainage culvert 104 is provided at the upper end of the concrete base 103. The lower drainage pipes 101 located in the area covered by the main drainage culvert 104 are connected to the main drainage culvert 104. The outside of the main drainage culvert 104 is provided with a main drainage culvert connected to the main drainage culvert. The culvert 104 is connected and is inclined along the upper outside and extends to the ground surface. A plurality of upper drainage pipes 106 are arranged above the concrete base 103. The upper drainage pipes 106 in the coverage area of ​​the main drainage culvert 104 are connected to the main drainage culvert 104 and the remaining upper drainage pipes 106 are connected to the corresponding lower drainage pipes 101. A concrete top plate 107 is cast between the lower drainage pipes 101 above the concrete base 103. The top end of each upper drainage pipe 106 extends to the top surface of the concrete top plate 107. A permeable filter layer is laid on the top surface of the concrete top plate 107 and on the outside of the sub-drainage culvert 105. The permeable filter layer is used to stack the slag body 4.

[0040] In this way, when the karst depression sinkhole blocking drainage system is used for drainage, the internal water of the slag body 4 enters the main drainage culvert 104 through the permeable filter layer and the upper drainage pipes 106 in turn, and the surrounding water of the slag body 4 enters the main drainage culvert 104 through the branch drainage culvert 105. The water entering the main drainage culvert 104 is discharged into the underground river 3 through the lower drainage pipes 101. Therefore, the karst depression sinkhole blocking drainage system can effectively block the sinkhole 2, so that the water can be piled up on the permeable filter layer above the sinkhole 2. The slag body 4 is discharged, and the water collected inside and around the slag body 4 can be discharged into the underground river 3 in time to ensure smooth drainage of the karst depression and the stability of the foundation bearing capacity of the karst depression, wherein the permeable filter layer plays a role of water permeability and anti-filtration to prevent the clay and other fine particles in the slag body 4 from affecting the smooth drainage of the upper drainage pipes 106, thereby preventing the clay and other fine particles in the slag body 4 from affecting the smooth drainage of the main drainage culvert 104, the branch drainage culvert 105 and the lower drainage pipes 101.

[0041] In one embodiment, Figure 1 As shown, each lower drainage pipe 101 and each upper drainage pipe 106 are arranged vertically, and the main drainage culvert 104 is arranged horizontally; the top of each upper drainage pipe 106 is covered with a geotextile wrap 108, and a steel wire filter is tied to the outside of the geotextile wrap 108. In this way, the cooperation of the geotextile wrap 108 and the steel wire filter can further prevent the clay and other fine particles in the slag body 4 from entering the corresponding upper drainage pipe 106.

[0042] In one embodiment, Figure 1 As shown, a casting template serving as a concrete plug 102 is provided in the sinkhole 2, and the casting template includes a plurality of anchor rods 109 inserted and fixed around the side wall of the sinkhole 2 and a horizontal flexible steel mesh 1010 fixed by the plurality of anchor rods 109, and a horizontal wooden template 1011 is laid on the flexible steel mesh 1010; multiple layers of horizontal steel mesh 1012 are tied above the casting template in the sinkhole 2, and a plurality of dowel bars 1013 are inserted and fixed on the side wall of the sinkhole 2 above the casting template, and each lower drainage pipe 101 is arranged on the wooden template 1011, and the arrangement position of each lower drainage pipe 101 is determined according to the spacing between adjacent steel bars in each layer of steel mesh 1012. After the concrete plug 102 is cast, the wooden template 1011 corresponding to the position of the corresponding lower drainage pipe 101 is removed through each lower drainage pipe 101, so that each lower drainage pipe 101 is connected to the underground river 3. In this way, by setting up the multi-layer steel mesh 1012 and the plurality of dowel bars 1013, the anti-slip stability of the concrete plug 102 assembly formed by the combination of the concrete plug 102 and the concrete base 103 can be ensured, and by setting up the multi-layer steel mesh 1012, the structural strength of the formed concrete plug 102 can be ensured.

[0043] In one embodiment,

[0044] like Figure 1 As shown, a drainage pipe 1014 is provided outside the main drainage culvert 104, which is connected to the main drainage culvert 104 and extends to the ground surface along the upper side of the outer side. The upper ends of the sub-drainage culvert 105 and the drainage pipe 1014 are respectively connected to the corresponding intercepting drainage ditch 1015 on the ground surface. Figure 2 .

[0045] In this way, the water collected around the slag body 4 can enter the branch drainage culvert 105 and the drainage pipe 1014 respectively through the corresponding intercepting drainage ditch 1015, and the water entering the branch drainage culvert 105 and the drainage pipe 1014 will enter the main drainage culvert 104. Therefore, the drainage pressure of the branch drainage culvert 105 can be reduced by setting the drainage pipe 1014 for the discharge of the water collected around the slag body 4.

[0046] There are two drainage culverts 105 and two drainage pipes 1014; the main drainage culvert 104 and each drainage culvert 105 are cast in situ by concrete, wherein each drainage culvert 105 is integrally connected with the main drainage culvert 104, and the main drainage culvert 104 includes a total concrete bottom plate, a total concrete side wall and a total concrete top arch. Figure 3As shown, the branch drainage culvert 105 includes a branch concrete bottom plate 1051, a branch concrete side wall 1052 and a branch concrete top arch 1053; the lower drainage pipe 101, the upper drainage pipe 106 and the drainage pipeline 1014 are all spliced ​​together by multiple sections of prefabricated reinforced concrete pipes 1016.

[0047] Preferably, if Figure 3 As shown, a plurality of drainage holes 1054 are provided on the sub-concrete top arch 1053 and the sub-concrete side wall 1052 in the sub-drainage culvert 105, and the outer end of each drainage hole 1054 is covered with a geotextile wrap 108, and a steel wire filter is tied to the outer side of the geotextile wrap 108. A water-permeable filter layer is laid around the outer side of the sub-concrete top arch 1053 and the sub-concrete side wall 1052 in the sub-drainage culvert 105 and the outer side of the drainage pipe 1014. The water-permeable filter layer on the outer side of the drainage pipe 1014 is used to stack the slag body 4. Figure 1 In this way, the internal water collection part of the slag body 4 can enter the sub-drainage culvert 105 through the water-permeable filter layer outside the sub-drainage culvert 105 and the drainage holes 1054 in turn. Therefore, for the discharge of the internal water collection part of the slag body 4, the water-permeable filter layer outside the sub-drainage culvert 105 and the arrangement of the drainage holes 1054 on the sub-drainage culvert 105 can reduce the drainage pressure of each upper drainage pipe 106; and the arrangement of the geotextile wrap 108 and the wire filter can further prevent the clay and other fine particles in the slag body 4 from entering the corresponding drainage holes 1054.

[0048] Preferably, if Figure 1 As shown, the permeable filter layer includes an inner pebble layer 10171 and an outer gravel layer complex 10172, and the gravel layer complex 10172 includes two layers of gravel layers 101722 separated by geotextiles 101721, see Figure 4 and Figure 6In this way, the two layers of gravel layers 101722 in the outer gravel layer complex 10172 and the inner pebble layer 10171 both play a water-permeable role, and the geotextile 101721 in the outer gravel layer complex 10172 plays a filtering role, preventing the clay and other fine particles in the slag body 4 in direct contact with the gravel layer complex 10172 from entering the inner pebble layer 10171, or preventing the ground soil in direct contact with the gravel layer complex 10172 from entering the inner pebble layer 10171, thereby preventing the water permeability of the pebble layer 10171 from being affected. Among them, the maximum particle size of gravel in the gravel layer 101722 is 3 cm, and the content of gravel particles with a particle size less than 5 mm is not more than 20%, the content of fine-grained gravel particles with a particle size less than 0.075 mm is not more than 5%, and the porosity of the gravel layer 101722 is not more than 19%; the maximum particle size of pebbles in the pebble layer 10171 is 25 cm, the content of pebble particles with a particle size less than 5 mm is not more than 15%, and the content of pebble particles with a particle size less than 0.1 mm is not more than 5%.

[0049] Preferably, if Figure 4 and Figure 5 As shown, a plurality of reinforcing ribs 10161 are provided around the inner side of each reinforced concrete pipe 1016, wherein the thickness of the reinforcing ribs 10161 is preferably equal to the wall thickness of the reinforced concrete pipe 1016, wherein the reinforcing ribs 10161 can increase the disturbance and aeration of the flowing water body, thereby improving the flow capacity in the reinforced concrete pipe 1016. Figure 5 As shown, a plurality of tenons 10162 are provided around the edge of one end of each reinforced concrete tube 1016 and a plurality of grooves 10163 are provided around the edge of the other end. Each tenon 10162 at one end of each reinforced concrete tube 1016 is clamped in the corresponding groove 10163 at the other end of the adjacent reinforced concrete tube 1016.

[0050] A construction method for a karst depression sinkhole blocking and drainage system, used to form the above-mentioned karst depression sinkhole blocking and drainage system, comprises the following steps:

[0051] S1. Survey and record the sinkhole 2 in the karst depression, count the catchment area of ​​the karst depression, the size of the sinkhole 2 hole and the depth of the sinkhole 2, and design the dimensions of the main drainage culvert 104, the branch drainage culvert 105, the drainage pipe 1014, the lower drainage pipe 101, the upper drainage pipe 106, the concrete plug 102 and the concrete base 103; the vertical length of the concrete plug 102 shall not be less than 2-3 times the size of the sinkhole 2 hole, the overlap length of the concrete base 103 and the bedrock around the top edge of the sinkhole 2 shall be controlled according to 0.5-1 times the sum of the thickness of the concrete base 103 and the concrete top plate 107, and the concrete base 103 and the top of the sinkhole 2 shall be 0.5-1 times the sum of the thickness of the concrete base 103 and the concrete top plate 107. The overlap length of the bedrock around the edge is not less than 0.5m, and the concrete used for the concrete plug 102, the concrete base 103, and the concrete top plate 107 during casting is C20 buried stone concrete. The size design of the concrete plug 102 and the concrete base 103 must meet the anti-sliding calculation of the concrete plug 102 assembly formed by the combination of the concrete plug 102 and the concrete base 103, and the size design of the concrete base 103 must meet the shear calculation; the size design of the total drainage culvert 104, the branch drainage culvert 105, the drainage pipe 1014, and the upper drainage pipe 106 must meet the pressure calculation of the slag body 4 and other loads piled above, and must meet the drainage calculation of the regional water collection;

[0052] S2. Excavate the foundation trench of the drainage culvert 105, the drainage pipe 1014 and the concrete base 103 according to the design dimensions and construction technical requirements of the drainage culvert 105, the drainage pipe 1014 and the concrete base 103;

[0053] S3. According to the designed vertical length of the concrete plug 102, a plurality of anchor rods 109 are inserted and fixed at corresponding height positions around the side wall of the sinkhole 2, a horizontal flexible steel mesh 1010 is fixed by the plurality of anchor rods 109, and a horizontal wooden template 1011 is laid on the flexible steel mesh 1010, wherein the anchor rods 109, the flexible steel mesh 1010 and the wooden template 1011 cooperate to form a casting template for the first phase of concrete in the concrete plug 102, and the laying flatness of the flexible steel mesh 1010 and the wooden template 1011 is controlled to meet the casting requirements of the first phase of concrete in the concrete plug 102;

[0054] S4. Tie multiple layers of horizontal steel mesh 1012 above the casting formwork in the sinkhole 2, and determine the layout position of each lower drainage pipe 101 according to the spacing between adjacent steel bars in each layer of steel mesh 1012. Specifically, for the layout of each lower drainage pipe 101, each tenon 10162 at one end of each reinforced concrete pipe 1016 constituting the corresponding lower drainage pipe 101 is clamped in the corresponding groove 10163 at the other end of the adjacent reinforced concrete pipe 1016 to splice and form the corresponding lower drainage pipe 101, and the lower drainage pipe 101 is arranged on the wooden formwork 1011, wherein the multiple lower drainage pipes 101 are preferably arranged in a plum blossom shape. Based on the anti-slip stability of the concrete plug 102 assembly, a plurality of dowel bars 1013 are inserted and fixed on the side wall of the sinkhole 2 above the casting template, and based on the bearing capacity of the casting template set in step S3, the casting height of the first-phase concrete in the concrete plug 102 is determined and the first-phase concrete is cast between the lower drainage pipes 101 in the sinkhole 2, wherein the casting height of the first-phase concrete is not less than 0.8m, and before the first-phase concrete is cast and solidified, cement slurry is used for grouting and sealing to ensure the adhesion between the dowel bars 1013 and the bedrock of the side wall of the sinkhole 2, and between the first-phase concrete in the concrete plug 102 and the bedrock of the side wall of the sinkhole 2;

[0055] S5. Remove the wooden templates 1011 corresponding to the positions of the corresponding lower drainage pipes 101 through each lower drainage pipe 101, so that each lower drainage pipe 101 is connected with the underground river 3. After the first-phase concrete reaches the design strength, use the first-phase concrete as the casting template for the second-phase concrete in the concrete plug 102 and cast the second-phase concrete. After the second-phase concrete reaches the design strength, use the second-phase concrete as the casting template for the concrete base 103 and cast the concrete base 103 on the top surface of the second-phase concrete of the concrete plug 102 and around the top edge of the sinkhole 2.

[0056] S6. After the concrete base 103 reaches the design strength, first cast the main drainage culvert 104 on the upper end of the concrete base 103, and make the main drainage culvert 104 connected with the lower drainage pipe 101 in the coverage area of ​​the main drainage culvert 104. After the main drainage culvert 104 reaches the design strength, then arrange multiple upper drainage pipes 106 above the concrete base 103, and make the upper drainage pipes 106 in the coverage area of ​​the main drainage culvert 104 connected with the main drainage culvert 104, and make the remaining upper drainage pipes 106 connected with the corresponding lower drainage pipes 101, and then cast the concrete top plate 107 between the upper drainage pipes 106 above the concrete base 103. After the concrete top plate 107 is cast, cover the top of each upper drainage pipe 106 with a geotextile wrap 108, and tie a double-layer steel wire filter on the outside of the geotextile wrap 108;

[0057] S7, cast the branch drainage culvert 105 outside the main drainage culvert 104, and make the branch drainage culvert 105 and the main drainage culvert 104 connected and communicated, and lay the drainage pipe 1014 outside the main drainage culvert 104 and make the drainage pipe 1014 communicate with the main drainage culvert 104, and lay a permeable filter layer on the top surface of the concrete top plate 107 and on the outside of the sub-concrete top arch 1053 and the sub-concrete side wall 1052 in the branch drainage culvert 105, and lay a permeable filter layer around the outside of the drainage pipe 1014, and complete the construction of the karst depression intercepting drainage ditch 1015, so that the branch drainage culvert 105 and the drainage pipe 1014 are connected with the corresponding intercepting drainage ditch 1015, wherein before laying the drainage pipe 1014, first lay the permeable filter layer below the drainage pipe 1014, and after the drainage pipe 1014 is laid Afterwards, the permeable filter layer is laid on the side and top surface of the drainage pipe 1014, wherein the pebble layer 10171 in the permeable filter layer above the concrete top plate 107, outside the sub-drainage culvert 105 and outside the drainage pipe 1014 serves as an important drainage channel on the surface and inside of the slag body 4, and the thickness of the pebble layer 10171 in the permeable filter layer is determined according to the surface rainwater collection area of ​​the slag yard, and should not be less than 0.5m, and the thickness of the gravel layer 101722 on both sides of the geotextile 101721 in the gravel layer complex 10172 should not be less than 0.2m, wherein the foundation trench of the sub-drainage culvert 105 and the sub-concrete bottom plate 1051 of the sub-drainage culvert 105 should be made into a step shape, wherein the permeable filter layer laid on the top surface of the concrete top plate 107, outside the sub-drainage culvert 105 and outside the drainage pipe 1014 is used to stack the slag body 4.

[0058] A drainage method for a karst depression sinkhole blocking drainage system adopts the above-mentioned karst depression sinkhole blocking drainage system for drainage, specifically: the internal water of the slag body 4 enters the main drainage culvert 104 through the permeable filter layer and the upper drainage pipes 106 in turn, the water around the slag body 4 enters the main drainage culvert 104 through the branch drainage culverts 105, and the water entering the main drainage culvert 104 is discharged into the underground river 3 through the lower drainage pipes 101.

[0059] The present invention can overcome the defects of large settlement deformation and low water permeability guarantee rate caused by backfilling the sinkhole 2 with large blocks of stone in the traditional way, and can overcome the defect of loss of original drainage function of the sinkhole 2 caused by direct backfilling of the sinkhole 2 with concrete. The present invention can effectively block the sinkhole 2 and ensure smooth drainage of the karst depression, stability of the foundation bearing capacity of the karst depression and stability of the stacked slag body 4.

[0060] The present invention can solve the drainage problem of the engineering site itself when constructing a waste dump in a karst depression area, while eliminating the foundation safety hazards caused by sinkholes 2, karst caves, etc., ensuring the safety of the waste dump and the upper structure, and is also beneficial to maintaining the water balance of the original karst depression system itself.

[0061] The present invention realizes the basic reinforcement of the foundation of the karst depression site and the arrangement of engineering waste, thereby achieving the purpose of site utilization; the treatment measures of the sinkhole 2 of the present invention are simple, the engineering amount is small, the construction is convenient, the engineering investment is small, and the drainage guarantee rate is high. At the same time, by arranging reinforcement ribs 10161 on the inner side of the reinforced concrete pipe 1016, the problem of poor flow caused by alternating positive and negative pressures in the reinforced concrete pipe 1016 can be avoided; the main drainage culvert 104, the branch drainage culvert 105, the drainage pipe 1014 and the upper drainage pipe 106 in the present invention have good pressure resistance and high structural stability.

[0062] In summary, by using the karst depression sinkhole blocking and drainage system of the present invention, the stability of the slag dump foundation in a large karst depression, the safety of the site structure and the stability of the drainage can be ensured.

[0063] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A karst depression sinkhole blocking and drainage system, characterized by: The invention comprises a plurality of lower drainage pipes (101) located in a sinkhole (2) and connected to an underground river (3) below the sinkhole (2); a concrete plug (102) is cast between each of the lower drainage pipes (101) in the sinkhole (2); a concrete base (103) is cast around the top surface of the concrete plug (102) and the top edge of the sinkhole (2); a main drainage culvert (104) is provided at the upper end of the concrete base (103); some of the lower drainage pipes (101) are connected to the main drainage culvert (104); and the outside of the main drainage culvert (104) is provided with a continuous and extending A drainage culvert (105) extending to the ground surface, wherein a plurality of upper drainage pipes (106) are arranged above the concrete base (103), wherein some of the upper drainage pipes (106) are connected to the main drainage culvert (104) and the remaining upper drainage pipes (106) are connected to the corresponding lower drainage pipes (101), and a concrete top plate (107) is cast between the lower drainage pipes (101) above the concrete base (103), and a permeable filter layer is laid on the top surface of the concrete top plate (107) and on the outside of the drainage culvert (105), and the permeable filter layer is used for stacking slag (4).

2. A karst depression sinkhole blocking and drainage system according to claim 1, characterized in that: Each of the lower drainage pipes (101) and each of the upper drainage pipes (106) are arranged vertically, and the main drainage culvert (104) is arranged horizontally; the top of each of the upper drainage pipes (106) is covered with a geotextile wrap (108), and a steel wire filter is tied to the outside of the geotextile wrap (108).

3. The karst depression sinkhole blocking and drainage system according to claim 1, characterized in that: A casting template serving as the concrete plug (102) is provided in the sinkhole (2), the casting template comprising a plurality of anchor rods (109) inserted and fixed around the side wall of the sinkhole (2) and a horizontal flexible steel mesh (1010) fixed by the plurality of anchor rods (109), a horizontal wooden template (1011) being laid on the flexible steel mesh (1010); multiple layers of horizontal steel mesh (1012) are tied above the casting template in the sinkhole (2), and the sinkhole (2) above the casting template A plurality of inserted bars (1013) are inserted and fixed on the side wall, and each of the lower drainage pipes (101) is arranged on a wooden template (1011). The arrangement position of each lower drainage pipe (101) is determined according to the spacing between adjacent steel bars in each layer of the steel mesh (1012). After the concrete plug (102) is poured, the wooden template (1011) corresponding to the position of the corresponding lower drainage pipe (101) is removed through each of the lower drainage pipes (101), so that each of the lower drainage pipes (101) is connected to the underground river (3).

4. The karst depression sinkhole blocking and drainage system according to claim 1, characterized in that: A drainage pipe (1014) is also provided on the outside of the main drainage culvert (104), which is connected to the main drainage culvert (104) and is inclined along the upper side of the outside and extends to the ground surface. The upper ends of the branch drainage culvert (105) and the drainage pipe (1014) are respectively connected to corresponding intercepting drainage ditches (1015) on the ground surface.

5. A karst depression sinkhole blocking and drainage system according to claim 4, characterized in that: There are two of each of the branch drainage culverts (105) and the drainage pipe (1014); the main drainage culvert (104) and each of the branch drainage culverts (105) are formed by pouring concrete on site; the main drainage culvert (104) comprises a main concrete bottom plate, a main concrete side wall and a main concrete top arch; the branch drainage culvert (105) comprises a sub-concrete bottom plate (1051), a sub-concrete side wall (1052) and a sub-concrete top arch (1053); the lower drainage pipe (101), the upper drainage pipe (106) and the drainage pipe (1014) are all formed by splicing a plurality of sections of prefabricated reinforced concrete pipes (1016).

6. A karst depression sinkhole blocking and drainage system according to claim 5, characterized in that: A plurality of drainage holes (1054) are provided on the sub-concrete top arch (1053) and the sub-concrete side wall (1052) in the sub-drainage culvert (105); the outer end of each drainage hole (1054) is covered with a geotextile wrap (108); a steel wire filter is tied to the outer side of the geotextile wrap (108); a water-permeable filter layer is laid on the outer side of the sub-concrete top arch (1053) and the sub-concrete side wall (1052) in the sub-drainage culvert (105) and the outer side of the drainage pipe (1014); and the water-permeable filter layer on the outer side of the drainage pipe (1014) is used to stack slag (4).

7. A karst depression sinkhole blocking and drainage system according to claim 6, characterized in that: The permeable filter layer includes an inner pebble layer (10171) and an outer gravel layer complex (10172), and the gravel layer complex (10172) includes two gravel layers (101722) separated by a geotextile (101721).

8. The karst depression sinkhole blocking and drainage system according to claim 5, characterized in that: A plurality of reinforcing ribs (10161) are provided around the inner side surface of each reinforced concrete pipe (1016), a plurality of tenons (10162) are provided around the edge of one end of each reinforced concrete pipe (1016) and a plurality of grooves (10163) are provided around the edge of the other end, and each tenon (10162) at one end of each reinforced concrete pipe (1016) is clamped in a corresponding groove (10163) at the other end of an adjacent reinforced concrete pipe (1016).

9. A construction method for a karst depression sinkhole plugging and drainage system, used to form a karst depression sinkhole plugging and drainage system as claimed in any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Survey and record the sinkholes (2) in the karst depression, calculate the catchment area of ​​the karst depression, the size of the sinkhole (2) and the depth of the sinkhole (2), and design the size of the main drainage culvert (104), the branch drainage culvert (105), the lower drainage pipe (101), the upper drainage pipe (106), the concrete plug (102) and the concrete base (103); S2, excavating the foundation trench and the foundation of the concrete base (103) of the drainage culvert (105); S3, arranging a plurality of the lower drainage pipes (101) in the sinkhole (2); S4, pouring a concrete plug (102) between each of the lower drainage pipes (101) in the sinkhole (2), and pouring a concrete base (103) on the top surface of the concrete plug (102) and around the top edge of the sinkhole (2); S5, firstly arranging a main drainage culvert (104) on the upper end of the concrete base (103), then arranging a plurality of upper drainage pipes (106) above the concrete base (103), then pouring a concrete top plate (107) between the upper drainage pipes (106) above the concrete base (103), and then arranging a branch drainage culvert (105) outside the main drainage culvert (104); S6. A water-permeable filter layer is laid on the top surface of the concrete top plate (107) and on the outside of the drainage culvert (105). The slag body (4) is stacked on the water-permeable filter layer.

10. A drainage method for a karst depression sinkhole blocking drainage system, using the karst depression sinkhole blocking drainage system as claimed in any one of claims 1 to 8 for drainage, characterized in that: Specifically, the water collected inside the slag body (4) enters the main drainage culvert (104) through the permeable filter layer and the upper drainage pipes (106) in turn, and the water collected around the slag body (4) enters the main drainage culvert (104) through the branch drainage culverts (105), and the water entering the main drainage culvert (104) is discharged into the underground river (3) through the lower drainage pipes (101).

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