阅读说明：本技术 一种在采煤塌陷区施工植被坑的施工方法 (Construction method for constructing vegetation pit in coal mining subsidence area ) 是由 周成军 李志伟 杨存慧 于 2021-01-05 设计创作，主要内容包括：本发明公开了一种在采煤塌陷区施工植被坑的施工方法,包括如下步骤：S01：在塌陷区的斜坡面上开挖用于植被的斜坡凹坑；S02：在斜坡凹坑的下部朝向塌陷裂缝开挖疏水沟,所述疏水沟连通所述斜坡凹坑与所述塌陷裂缝；其中,在沿着从所述斜坡凹坑至所述塌陷裂缝的方向上,所述疏水沟逐渐向下倾斜；S03：向所述疏水沟中铺设砾石；S04：向所述疏水沟与所述斜坡凹坑的交接处铺设疏水材料；S05：向斜坡凹坑中回填土壤,形成植被坑。本发明公开的一种在采煤塌陷区施工植被坑的施工方法,利用疏水沟与塌陷裂缝连通,将植被坑中积累的盐碱通过疏水沟排入塌陷裂缝,最后由塌陷裂缝渗入地下含水层,达到排碱,改良土壤的目的。(The invention discloses a construction method for constructing vegetation pits in a coal mining subsidence area, which comprises the following steps: s01: excavating slope pits for vegetation on the slope surface of the subsidence area; s02: excavating a hydrophobic ditch towards the collapse crack at the lower part of the slope pit, wherein the hydrophobic ditch is communicated with the slope pit and the collapse crack; wherein the hydrophobic trench slopes gradually downward in a direction along the collapsed crack from the sloped pocket; s03: paving gravel into the drainage ditch; s04: laying a hydrophobic material at the joint of the hydrophobic ditch and the slope pit; s05: and backfilling soil into the inclined slope pits to form vegetation pits. The invention discloses a construction method for constructing vegetation pits in a coal mining subsidence area, which utilizes the communication of a hydrophobic ditch and a subsidence crack to discharge saline and alkaline accumulated in the vegetation pits into the subsidence crack through the hydrophobic ditch, and finally the subsidence crack permeates into an underground water-bearing layer to achieve the purposes of discharging the alkaline and improving the soil.)

1. A construction method for constructing vegetation pits in a coal mining subsidence area is characterized by comprising the following steps:

s01: excavating slope pits for vegetation on the slope surface of the subsidence area;

s02: excavating a hydrophobic ditch towards the collapse crack at the lower part of the slope pit, wherein the hydrophobic ditch is communicated with the slope pit and the collapse crack;

wherein the hydrophobic trench slopes gradually downward in a direction along the collapsed crack from the sloped pocket;

s03: paving gravel into the drainage ditch;

s04: laying a hydrophobic material at the joint of the hydrophobic ditch and the slope pit;

s05: and backfilling soil into the inclined slope pits to form vegetation pits.

2. The construction method for constructing the vegetation pit in the coal mining subsidence area according to claim 1, wherein the vegetation pit is a fish scale pit.

3. The construction method for constructing the vegetation pit in the coal mining subsidence area according to claim 1, wherein the vegetation pit is a horizontal ditch.

4. The construction method for constructing vegetation pits in the coal mining subsidence area according to claim 1,

the hydrophobic material is tree branches, straws or a combination thereof.

5. The construction method for constructing vegetation pits in the coal mining subsidence area according to claim 1,

the hydrophobic ditch is positioned in a surface soil layer;

the width and the depth of the hydrophobic ditch are not less than 300mm, and the hydrophobic ditch penetrates through a saline-alkali layer inside the topsoil layer.

6. The construction method for constructing vegetation pits in the coal mining subsidence area according to claim 5,

the step S03 further includes:

and paving graded gravels into the hydrophobic ditch, wherein the coarse gravel is arranged in the middle, and the fine gravel is arranged at the periphery.

7. The construction method for constructing vegetation pits in the coal mining subsidence area according to claim 1,

the hydrophobic trench is in a weathered rock formation;

the width and the depth of the hydrophobic ditch are not less than 200 mm.

8. The construction method for constructing vegetation pits in the coal mining subsidence area according to claim 7,

the step S03 further includes:

and paving graded gravel into the hydrophobic ditch, wherein the coarse gravel is arranged at the lower part, and the fine gravel is arranged at the upper part.

9. The construction method for constructing vegetation pits in the coal mining subsidence area according to claim 1,

and constructing a plurality of hydrophobic ditches around each slope pit, wherein each hydrophobic ditch is respectively communicated with a plurality of collapse cracks.

10. The construction method for constructing vegetation pits in the coal mining subsidence area according to claim 1,

the gradient of the hydrophobic ditch is greater than or equal to 1%.

Technical Field

The invention relates to the technical field of coal mining ecological management, in particular to a construction method for constructing vegetation pits in a coal mining subsidence area.

Background

In northwest China, drought and rain are caused, and the landform morphology is mainly the hilly lands of the hills and hills, and gullies are vertical and horizontal. Most of the top soil layer is sandy soil, and the thickness of most of the top soil layer is less than 1 m; the surface soil layer of partial area is thicker, and the local part can reach tens of meters, but the deep-color saline-alkali layer is arranged at the depth of about 1m, and the root system of the tree is difficult to penetrate through the saline-alkali layer. The soil salinization phenomenon is serious, the rainfall is small, most of the rainfall is concentrated in 7-9 months, and the vegetation growth is not facilitated. The northwest area is also a coal resource enrichment area, the coal burial depth is shallow, and the ecological management task of the coal mining subsidence area is very difficult.

The existing ecological treatment measures are mainly to fill and block ground surface cracks and carry out vegetation recovery treatment according to local conditions.

The existing afforestation method has the main problems that the alkali discharge effect is poor, the salt and alkali amount is gradually accumulated, a white alkali layer appears on the surface of a vegetation pit, and the survival and the normal growth of nursery stocks are influenced, and the main reasons are as follows:

firstly, the method comprises the following steps: saline-alkali accumulation is caused by seedling irrigation. In the stage of seedling initial growth and survival, the amount and frequency of water needed to be irrigated are large, and the saline alkali content of the irrigated water is large. After each irrigation, the vegetation pit is full of water, and along with continuous evaporation, saline and alkaline in the water are accumulated and are brought to the ground along with water evaporation to form white alkaline peel.

II, secondly: the rainwater alkali-removing effect is poor. During rainstorm in 7-9 months, as most sandy loam exists in the northwest area, rainwater infiltration speed is high, the saline and alkali on the surface of the vegetation pit is rapidly dissolved by initial rainwater and brought to the lower part of the vegetation pit, and when the vegetation pit is full of water to form surface runoff, the saline and alkali content in the flowing water is less.

Disclosure of Invention

The invention aims to provide a construction method for constructing a vegetation pit in a coal mining subsidence area, which utilizes the communication of a hydrophobic ditch and a subsidence crack to discharge saline and alkaline accumulated in the vegetation pit into the subsidence crack through the hydrophobic ditch, and finally the subsidence crack permeates into an underground water-bearing layer to achieve the purposes of alkali discharge and soil improvement.

The technical scheme of the invention provides a construction method for constructing a vegetation pit in a coal mining subsidence area, which comprises the following steps:

s01: excavating slope pits for vegetation on the slope surface of the subsidence area;

s02: excavating a hydrophobic ditch towards the collapse crack at the lower part of the slope pit, wherein the hydrophobic ditch is communicated with the slope pit and the collapse crack;

wherein the hydrophobic trench slopes gradually downward in a direction along the collapsed crack from the sloped pocket;

s03: paving gravel into the drainage ditch;

s04: laying a hydrophobic material at the joint of the hydrophobic ditch and the slope pit;

s05: and backfilling soil into the inclined slope pits to form vegetation pits.

Further, the vegetation pits are fish scale pits.

Further, the vegetation pit is a horizontal ditch.

Further, the hydrophobic material is tree branches, straws and a combination thereof.

Further, the hydrophobic ditch is in a topsoil layer;

the width and the depth of the hydrophobic ditch are not less than 300mm, and the hydrophobic ditch penetrates through a saline-alkali layer inside the topsoil layer.

Further, the step S03 further includes:

and paving graded gravels into the hydrophobic ditch, wherein the coarse gravel is arranged in the middle, and the fine gravel is arranged at the periphery.

Further, the hydrophobic trench is in a weathered rock formation;

the width and the depth of the hydrophobic ditch are not less than 200 mm.

Further, the step S03 further includes:

and paving graded gravel into the hydrophobic ditch, wherein the coarse gravel is arranged at the lower part, and the fine gravel is arranged at the upper part.

Furthermore, a plurality of hydrophobic ditches are constructed around each slope pit, and each hydrophobic ditch is respectively communicated with the plurality of collapse cracks.

Further, the gradient of the hydrophobic ditch is greater than or equal to 1%.

By adopting the technical scheme, the method has the following beneficial effects:

the invention provides a construction method for constructing vegetation pits in a coal mining subsidence area, which is characterized in that a hydrophobic ditch is communicated with a subsidence crack, saline and alkali accumulated in the vegetation pits are discharged into the subsidence crack through the hydrophobic ditch, and finally the subsidence crack permeates into an underground water-bearing layer to achieve the purposes of alkali discharge and soil improvement.

Drawings

FIG. 1 is a schematic view of vegetation planted with vegetation;

FIG. 2 is a cross-sectional view taken along the hydrophobic channel of FIG. 1;

FIG. 3 is a schematic view showing the communication of vegetation pits, drainage ditches and collapsed cracks;

FIG. 4 is a schematic view of the arrangement of the hydrophobic material and the gravel with the coarse gravel down and the fine gravel up;

FIG. 5 is a schematic representation of the hydrophobic trench in the topsoil layer and through the salt-alkali layer with coarse gravel in the middle and fine gravel in the periphery.

Detailed Description

The following further describes embodiments of the present invention with reference to the accompanying drawings. In which like parts are designated by like reference numerals. It should be noted that the terms "front," "back," "left," "right," "upper" and "lower" used in the following description refer to directions in the drawings, and the terms "inner" and "outer" refer to directions toward and away from, respectively, the geometric center of a particular component.

As shown in fig. 1 to 3, a construction method for constructing a vegetation pit in a coal mining subsidence area according to an embodiment of the present invention includes the following steps:

s01: slope pits 21 for vegetation are dug on the slope surfaces 11 of the subsidence area 1.

S02: and excavating a hydrophobic ditch 4 towards the collapsed crack 3 at the lower part of the slope pit 21, wherein the hydrophobic ditch 4 is communicated with the slope pit 21 and the collapsed crack 3.

Wherein the hydrophobic trench 4 is gradually inclined downward in a direction from the sloped recess 21 to the collapsed crack 3.

S03: gravel 5 is laid into the hydrophobic trench 4.

S04: hydrophobic material 6 is applied to the intersection of the hydrophobic trench 4 and the sloped pit 21.

S05: soil 22 is backfilled in the sloping pit 21 to form a vegetation pit 2.

In the coal mining process, a goaf is formed below the ground surface, a collapse area 1 is formed on the corresponding ground surface, and the collapse area 1 is provided with a slope surface 11. Meanwhile, a collapse crack 3 is formed in the collapse area 1, and the collapse crack 3 is communicated with a water flowing crack zone under the ground surface, so that water can be introduced into an underground aquifer.

In order to discharge salt and alkali in the vegetation pit 2 on the ground surface, the technical scheme adopts a hydrophobic ditch 4 to communicate the collapse crack 3 with the vegetation pit 2. When rainstorm occurs or the vegetation pit 2 is watered thoroughly, high-concentration saline alkali in the vegetation pit 2 is discharged into the collapse crack 3 through the hydrophobic ditch 4 and then permeates into the underground aquifer through the collapse crack 3.

The vegetation pit 2 in the invention is a pit for planting the plant 7, and the plant 7 can be a sapling, a plant, and the like. The hydrophobic channel 4 is located below the surface of the earth and extends along a strike line 41. The drainage ditch 4 is inclined, and the height of the drainage ditch 4 is gradually lower from the vegetation pit 2 to the collapse crack 3, so that drainage is facilitated.

The hydrophobic ditch 4 is filled with gravel 5 and can guide water.

The hydrophobic material 6 is laid at the intersection of the hydrophobic ditch 4 and the sloped recesses 21 for guiding the water in the sloped recesses 21 into the hydrophobic ditch 4.

The slope pits 21 are filled with soil 22 for growing plants 7.

When the rain is small or the vegetation pit 2 is not watered through, water is generally absorbed in the soil 7 and does not drain into the hydrophobic trench 4 through the hydrophobic material 6.

When the rainwater is great or vegetation hole 2 waters thoroughly, the saline and alkaline in the vegetation hole 2 of water dissolution rapidly and with saline and alkaline area to vegetation hole 2's lower part, saline and alkaline discharges into the crack of caving 3 through the ditch of dredging 4, permeates secret aquifer or deep stratum by the crack of caving 3 again.

The collapse cracks 3 communicated with the drainage ditches 4 are cracks in the water flowing fractured zone so as to ensure that water flowing into the collapse cracks 3 can reach the aquifer or the deep rock stratum along the cracks.

The method for constructing the vegetation pit in the coal mining subsidence area comprises the following steps:

first, a slope pit 21 for vegetation is dug on the slope surface 11 of the subsidence area 1.

Then, a hydrophobic trench 4 is dug at the lower portion of the slope pit 21 toward the collapsed crack 3, and the hydrophobic trench 4 communicates the slope pit 21 with the collapsed crack 3.

Wherein the hydrophobic trench 4 is gradually inclined downward in a direction from the sloped recess 21 to the collapsed crack 3.

Thereafter, gravel 5 is laid in the hydrophobic trench 4.

Then, the hydrophobic material 6 is applied to the junction of the hydrophobic trench 4 and the sloped pit 21.

And finally, backfilling soil 22 into the sloping pit 21 to form a vegetation pit 2.

In one embodiment, the vegetation pits 2 are fish scale pits. Half-moon shaped pits are dug on the slope surface 11 from top to bottom along contour lines and are arranged in a shape like a Chinese character 'pin', so the fish scale pits are called as fish scale pits. The soil taken out by digging the pit is cultivated into a semicircular cofferdam below the pit to increase the water storage capacity, so that the fish scale pit has certain water storage capacity, trees are planted in the pit, the soil can be preserved, the water and the fertilizer can be preserved, and the survival of seedlings planted in the pit is facilitated.

In one embodiment, vegetation pit 2 is a horizontal trench. The horizontal channel is an intercepting channel, a water storage channel and the like which are built on the slope surface 11 at regular intervals along the contour line.

In one embodiment, the hydrophobic material 5 is tree branches, straw or a combination thereof, which can be obtained from local sources, thereby saving cost.

In one embodiment, as shown in FIG. 5, hydrophobic trench 4 is in topsoil layer 12. The width and the depth of the hydrophobic ditch 4 are not less than 300mm, and the hydrophobic ditch 4 penetrates through the saline-alkali layer 13 inside the topsoil layer 12.

When the topsoil layer 12 is thicker, the hydrophobic ditch 4 is arranged in the topsoil layer 12, the width and the depth of the hydrophobic ditch 4 are not less than 300mm, and the saline-alkali layer 13 inside the topsoil layer 12 is dug through as much as possible, so that the saline-alkali in the saline-alkali layer 13 can be discharged.

In one embodiment, as shown in fig. 5, the step S03 further includes:

graded gravel 5 is laid into the hydrophobic trench 4 with coarse gravel 52 in the middle and fine gravel 51 in the periphery.

The gravel 5 has a particle size of not more than 25mm, and gravel having a particle size of 15mm to 25mm is referred to as coarse-grained gravel 52, and gravel having a particle size of 5mm to 15mm is referred to as fine-grained gravel 51.

The gaps between the adjacent coarse gravel particles 52 are large, and hydrophobic property is facilitated. The gaps between the adjacent fine gravel particles 51 are small, so that the soil can be protected while the water is drained, and the soil is prevented from being washed away by water.

The fine gravel particles 51 surround the coarse gravel particles 52, and protect the surrounding soil.

In one embodiment, the hydrophobic trench 4 is in a weathered rock formation, and the width and the depth of the hydrophobic trench 4 are not less than 200 mm.

When the surface soil layer 12 is thin and the excavation depth is lower than that of the weathered rock layer in the surface soil layer 12, the hydrophobic ditch 4 with the width and the depth not less than 200mm is excavated downwards from the weathered rock layer.

In one embodiment, as shown in fig. 5, step S03 further includes:

graded gravel 5 is laid into the hydrophobic ditch 4, wherein the coarse gravel 52 is arranged at the lower part, the fine gravel 51 is arranged at the upper part, and the fine gravel 51 can protect the soil above.

In one embodiment, a plurality of hydrophobic ditches 4 are constructed around each slope pit 21, each hydrophobic ditch 4 is respectively communicated with a plurality of collapse cracks 3, and the hydrophobic ditches 4 are communicated with the collapse cracks 3 to form a grid shape, so that saline and alkali are drained and drained favorably.

In one embodiment, the slope of the hydrophobic groove 4 is greater than or equal to 1%. The direction of the communicated collapse crack 3 of the hydrophobic ditch 4 is a negative slope, the slope is generally not less than 1%, and the slope in the flow direction is gradually increased so as to ensure the smooth water flowing in the ditch.

In one embodiment, the slope surfaces 11 of the subsidence area 1 are ridges and hills slope surfaces, horizontal ditches or fish scale pits are arranged on the ridges and hills slope surfaces along a direction close to a horizontal line, and the row spacing and the size of the horizontal ditches or the fish scale pits are determined according to the needs of planted trees. The trees are planted in the horizontal ditches preferentially.

In one embodiment, the hydrophobic trench 4 may be dug down the bottom of a horizontal trench for planting seedlings by digging the horizontal trench along the slope contour. When the horizontal ditch is deeper, the hydrophobic ditch 4 can be directly paved on one side of the bottom of the horizontal ditch.

In one embodiment, the drainage ditch 4 should avoid the main root system when the planted nursery stock is a tall tree with a main root system.

The invention provides a construction method for constructing vegetation pits in a coal mining subsidence area, which adopts a hydrophobic ditch 4 (alkali discharge underdrain) connected with a subsidence crack 3 to discharge saline and alkali to the ground through the subsidence crack 3, thereby solving the problem of no-place discharge of the saline and alkali. The saline alkali is discharged from the collapsed fracture 3, and the saline alkali may be remained in the collapsed fracture 3 and also facilitate the closure of the collapsed fracture 3.

According to the needs, the above technical schemes can be combined to achieve the best technical effect.

The foregoing is considered as illustrative only of the principles and preferred embodiments of the invention. It should be noted that, for those skilled in the art, several other modifications can be made on the basis of the principle of the present invention, and the protection scope of the present invention should be regarded.