阅读说明：本技术 一种露天矿的地下储水系统的修筑方法 (Construction method of underground water storage system of strip mine ) 是由 李全生 陈树召 曹治国 张润廷 李雁飞 高思华 王常建 荣宝 魏志丹 于 2021-08-23 设计创作，主要内容包括：本发明公开了一种露天矿的地下储水系统的修筑方法,包括如下步骤：S1：确定蓄水区的边界；S2：构筑人工隔水层；S3：构筑主挡水坝；S4：构筑毛石集水系统；S5：构筑储水体；S6：形成隐藏式的地下储水系统。本发明提供的露天矿的地下储水系统的修筑方法,利用露天矿内排土场来构建地下储水系统,空间充裕、容量大、成本低；以露天矿的剥离物为建库和储水物料,来源广泛、取料方便、成本低廉；在蓄水区中构筑毛石集水系统及由砾石构成的储水体,汇水效果好,提高储水的回收利用效率。(The invention discloses a building method of an underground water storage system of a strip mine, which comprises the following steps: s1: determining the boundary of the impoundment area; s2: constructing an artificial water-resisting layer; s3: constructing a main retaining dam; s4: constructing a rubble water collecting system; s5: constructing a water storage body; s6: forming a hidden underground water storage system. The method for building the underground water storage system of the strip mine provided by the invention has the advantages that the underground water storage system is built by utilizing the earth discharge field in the strip mine, the space is abundant, the capacity is large, and the cost is low; the strip material of the strip mine is used as a material for building a reservoir and storing water, so that the strip mine has wide sources, convenient material taking and low cost; a rubble water collecting system and a water storage body formed by gravels are constructed in the water storage area, the water collecting effect is good, and the recycling efficiency of the stored water is improved.)

1. A building method of an underground water storage system of a strip mine is characterized by comprising the following steps:

s1: determining a boundary of an impoundment area, comprising:

in the direction vertical to the ground surface, taking the lower boundary of the end slope aquifer as the lower boundary of the impoundment area;

in the horizontal range, offsetting a preset distance into the open pit to be used as a horizontal area boundary of the water storage area;

s2: constructing an artificial water-resisting layer in the open pit in a manner of discharging soil below the lower boundary of the water storage area, wherein the artificial water-resisting layer is connected with the end slope water-resisting layer;

wherein, in the horizontal range, the water storage area is positioned in the boundary range of the artificial water-resisting layer;

s3: constructing a main retaining dam with a trapezoidal section in an internal soil discharge mode outside the horizontal region boundary, wherein the upper boundary of the main retaining dam is higher than the upper boundary of the impoundment area, and the lower boundary of the main retaining dam is lower than the lower boundary of the impoundment area;

s4: constructing a rubble water collecting system in the water storage area in an inner soil discharge mode, wherein the rubble water collecting system comprises a plurality of rubble walls which are radially arranged;

s5: discharging gravels between any two adjacent rubble walls in an internal soil discharge mode to construct a water storage body;

s6: and the rubble water collecting system and the water storage body are covered by the inner soil discharging mode for discharging soil in the water storage area, so that a hidden underground water storage system is formed.

2. The method of constructing an underground water storage system for an open pit mine according to claim 1, further comprising the steps of:

s7: water pumping hole, water injection hole and monitoring hole constructed from top to water storage area

The water pumping hole is located in the center of the rubble water collecting system, the water injection hole is located at one end, away from the center of the rubble water collecting system, of the rubble wall, and the monitoring hole is located in the boundary of the water storage body.

3. The method of constructing an underground water storage system for an open pit mine according to claim 1, further comprising the steps of:

and constructing auxiliary retaining dams at the inner side and the outer side of the main retaining dam in an internal dumping mode.

4. The method of constructing an underground water storage system for an open pit mine according to claim 1, further comprising the steps of:

constructing a plurality of vertically extending grouting holes into the main retaining dam, wherein the lower ends of the grouting holes extend into the artificial water-resisting layer;

and injecting a cementing agent into the grouting hole.

5. The method of constructing an underground water storage system for an open-pit mine according to claim 4, wherein the distance between two adjacent grouting holes is 1 to 1.5 times the height of the main dam.

6. The method of constructing an underground water storage system for an open pit mine according to claim 1, further comprising the steps of:

and high-level water resisting layers are constructed around the main retaining dam in an internal soil discharge mode.

7. The method of constructing an underground water storage system for an open pit mine according to claim 1, wherein the slope of the main dam is between 20 ° and 25 °.

8. The method of constructing an underground water storage system for an open pit mine according to claim 1,

and when the boundary of the horizontal area is located, the preset distance of the deviation to the open pit is 5-7 times of the average height of the end slope aquifer.

9. The method of constructing an underground water storage system for an open pit mine according to claim 1,

when the artificial water-resisting layer is constructed:

when the height of the constructed space is less than or equal to 10m, discharging easily cemented mudstone materials into the constructed space, and adopting an engineering vehicle to tamp the mudstone materials in a reciprocating manner;

and if the height of the constructed space is more than 10m, firstly, discarding the stripped objects in the space which is less than 10m away from the lower boundary of the water storage area, then discarding the easily cemented mud-rock materials in the space which is within 10m away from the lower boundary of the water storage area, and adopting an engineering vehicle to tamp the easily cemented mud-rock materials in a reciprocating manner.

10. The method of constructing an underground water storage system for an open pit mine according to claim 1,

in determining the upper and lower boundaries of the impoundment area:

selecting upper and lower boundaries corresponding to the end slope aquifers in the exposed strata of the end slope of the strip mine to determine the upper and lower boundaries of the impoundment area;

if the height of the end upper aquifer exceeds 45m, taking the lower boundary of the end upper aquifer as the lower boundary of the impoundment area, and taking a plane 45m higher than the lower boundary of the end upper aquifer as the upper boundary of the impoundment area;

if the height of the end upper aquifer is less than 30m, taking the lower boundary of the end upper aquifer as the lower boundary of the impoundment area, and taking a plane higher than the lower boundary of the end upper aquifer by 30m as the upper boundary of the impoundment area;

and if the height of the end upper aquifer is more than 30m and less than 45m, taking the lower boundary of the end upper aquifer as the lower boundary of the impoundment area and taking the upper boundary of the end upper aquifer as the upper boundary of the impoundment area.

Technical Field

The invention relates to the technical field of strip mines, in particular to a building method of an underground water storage system of a strip mine.

Background

The strip mine can influence regional water resource balance while developing mineral resources on a large scale to meet the national economic development demand. On one hand, in order to ensure the safety and normal continuation of the strip mine production, atmospheric precipitation in the pit range and underground water rushing into the pit need to be discharged, so that a large amount of drainage cost is generated; on the other hand, in order to meet the environmental protection requirements of mine production, water sprinkling and dust settling, ecological restoration and the like, strip mines need to use a large amount of water resources, so that a large amount of water purchasing cost is generated. Therefore, it is necessary to establish a large-scale water storage system to reduce drainage and purchase of water.

The existing ground adjusting water tank has the problems of large occupied area, high possibility of being influenced by climate and external pollution, high construction cost, high water transfer cost and the like, and the open pit waste dump has a large amount of space for utilization, so that a system for storing water by utilizing the pore space in the waste dump is urgently needed to be developed.

Disclosure of Invention

The invention aims to provide a building method of an underground water storage system of a strip mine, which is particularly suitable for the strip mine with large amount of stripped objects in the mining process, wherein atmospheric precipitation or underground water is abundant.

The technical scheme of the invention provides a building method of an underground water storage system of an open pit mine, which comprises the following steps:

s1: determining a boundary of an impoundment area, comprising:

in the direction vertical to the ground surface, taking the lower boundary of the end slope aquifer as the lower boundary of the impoundment area;

in the horizontal range, offsetting a preset distance into the open pit to be used as a horizontal area boundary of the water storage area;

s2: constructing an artificial water-resisting layer in the open pit in a manner of discharging soil below the lower boundary of the water storage area, wherein the artificial water-resisting layer is connected with the end slope water-resisting layer;

wherein, in the horizontal range, the water storage area is positioned in the boundary range of the artificial water-resisting layer;

s3: constructing a main retaining dam with a trapezoidal section in an internal soil discharge mode outside the horizontal region boundary, wherein the upper boundary of the main retaining dam is higher than the upper boundary of the impoundment area, and the lower boundary of the main retaining dam is lower than the lower boundary of the impoundment area;

s4: constructing a rubble water collecting system in the water storage area in an inner soil discharge mode, wherein the rubble water collecting system comprises a plurality of rubble walls which are radially arranged;

s5: discharging gravels between any two adjacent rubble walls in an internal soil discharge mode to construct a water storage body;

s6: and the rubble water collecting system and the water storage body are covered by the inner soil discharging mode for discharging soil in the water storage area, so that a hidden underground water storage system is formed.

In one optional technical scheme, the method for building the underground water storage system of the strip mine further comprises the following steps:

s7: water pumping hole, water injection hole and monitoring hole constructed from top to water storage area

The water pumping hole is located in the center of the rubble water collecting system, the water injection hole is located at one end, away from the center of the rubble water collecting system, of the rubble wall, and the monitoring hole is located in the boundary of the water storage body.

In one optional technical scheme, the method for building the underground water storage system of the strip mine further comprises the following steps:

and constructing auxiliary retaining dams at the inner side and the outer side of the main retaining dam in an internal dumping mode.

In one optional technical scheme, the method for building the underground water storage system of the strip mine further comprises the following steps:

constructing a plurality of vertically extending grouting holes into the main retaining dam, wherein the lower ends of the grouting holes extend into the artificial water-resisting layer;

and injecting a cementing agent into the grouting hole.

In one optional technical scheme, the method for building the underground water storage system of the strip mine further comprises the following steps:

the distance between two adjacent grouting holes is 1-1.5 times of the height of the main water retaining dam.

In one optional technical scheme, the method for building the underground water storage system of the strip mine further comprises the following steps:

and high-level water resisting layers are constructed around the main retaining dam in an internal soil discharge mode.

In one optional technical scheme, the slope inclination of the main water retaining dam is 20-25 degrees.

In one optional technical scheme, the method for building the underground water storage system of the strip mine further comprises the following steps:

and when the boundary of the horizontal area is located, the preset distance of the deviation to the open pit is 5-7 times of the average height of the end slope aquifer.

In one optional technical scheme, the method for building the underground water storage system of the strip mine further comprises the following steps:

when the artificial water-resisting layer is constructed:

when the height of the constructed space is less than or equal to 10m, discharging easily cemented mudstone materials into the constructed space, and adopting an engineering vehicle to tamp the mudstone materials in a reciprocating manner;

and if the height of the constructed space is more than 10m, firstly, discarding the stripped objects in the space which is less than 10m away from the lower boundary of the water storage area, then discarding the easily cemented mud-rock materials in the space which is within 10m away from the lower boundary of the water storage area, and adopting an engineering vehicle to tamp the easily cemented mud-rock materials in a reciprocating manner.

In one optional technical scheme, the method for building the underground water storage system of the strip mine further comprises the following steps:

in determining the upper and lower boundaries of the impoundment area:

selecting upper and lower boundaries corresponding to the end slope aquifers in the exposed strata of the end slope of the strip mine to determine the upper and lower boundaries of the impoundment area;

if the height of the end upper aquifer exceeds 45m, taking the lower boundary of the end upper aquifer as the lower boundary of the impoundment area, and taking a plane 45m higher than the lower boundary of the end upper aquifer as the upper boundary of the impoundment area;

if the height of the end upper aquifer is less than 30m, taking the lower boundary of the end upper aquifer as the lower boundary of the impoundment area, and taking a plane higher than the lower boundary of the end upper aquifer by 30m as the upper boundary of the impoundment area;

and if the height of the end upper aquifer is more than 30m and less than 45m, taking the lower boundary of the end upper aquifer as the lower boundary of the impoundment area and taking the upper boundary of the end upper aquifer as the upper boundary of the impoundment area.

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

the method for building the underground water storage system of the strip mine provided by the invention has the advantages that the underground water storage system is built by utilizing the earth discharge field in the strip mine, the space is abundant, the capacity is large, and the cost is low; the strip material of the strip mine is used as a material for building a reservoir and storing water, so that the strip mine has wide sources, convenient material taking and low cost; a rubble water collecting system and a water storage body formed by gravels are constructed in the water storage area, the water collecting effect is good, and the recycling efficiency of the stored water is improved.

Drawings

Fig. 1 is a flow chart of a method of constructing an underground water storage system for a strip mine according to the present invention;

FIG. 2 is a schematic illustration of an open pit formed in an end slope of an open pit mine;

FIG. 3 is a schematic view of an artificial isolation layer;

FIG. 4 is a schematic view illustrating a main dam, an auxiliary dam and a high-level isolation layer;

FIG. 5 is a schematic view of a reservoir being constructed in a impounded area;

FIG. 6 is a schematic view of a water injection hole and a water pumping hole being constructed in a water storage area from the upper backfill soil;

FIG. 7 is a schematic view of a rubble water collection system constructed in an impoundment area;

FIG. 8 is a top view of the underground water storage system when the impound bodies are not yet covered by backfill.

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 8, a method for constructing an underground water storage system of a strip mine according to an embodiment of the present invention includes the following steps:

s1: determining the boundaries of the impoundment area 500, comprising:

the lower boundary of the end slope aquifer 3 is taken as the lower boundary of the impoundment area 500 in the direction perpendicular to the ground surface.

The horizontal extent is offset into the open pit 300 by a predetermined distance as the horizontal zone boundary of the impoundment area 500.

S2: an artificial water-resisting layer 5 is constructed in the open pit 300 below the lower boundary of the water storage area 500 in a soil discharging manner, and the artificial water-resisting layer 5 is connected with the end slope water-resisting layer 2.

Wherein, in the horizontal range, the impoundment area 500 is within the boundary range of the artificial water barrier 5.

S3: a main retaining dam 6 with a trapezoidal section is constructed outside the horizontal region boundary in an inner soil discharging manner, the upper boundary of the main retaining dam 6 is higher than the upper boundary of the impoundment area 500, and the lower boundary of the main retaining dam 6 is lower than the lower boundary of the impoundment area 500.

S4: the rubble catchment system 9 is built in a soil removal manner in the impounded area 500, wherein the rubble catchment system 9 comprises multi-faced rubble walls 91 arranged in a radial manner.

S5: and discharging gravel between any two adjacent rubble walls 91 in an internal soil discharge manner to construct the water storage body 10.

S6: the water storage area 500 is drained by an internal soil drainage mode to cover the rubble water collecting system 9 and the water storage body 10, so that a hidden underground water storage system is formed.

The open-pit mine adopts an internal dumping operation mode to operate, and can be called as an internal dumping open-pit mine.

An end slope is formed after the strip mine is mined, and comprises a side end slope 200 along the working line and a rear end slope 100 at the rear end of the working line, wherein the rear end slope 100 is a non-working end slope, and the side end slope 200 is a working end slope.

The end upper is provided with an end upper bottom layer 1, an end upper water-resisting layer 2, an end upper water-containing layer 3 and an end upper layer 4 from bottom to bottom. The upper bottom layer 1 and the upper layer 4 can be subdivided into a plurality of layers, which do not relate to the invention of the present application, so that the upper bottom layer below the upper water-resisting layer 2 and the upper layer above the upper water-containing layer 3 are collectively referred to as the upper bottom layer and the upper layer. The end slope water-resisting layer 2 is an underground original water-resisting layer, and the end slope water-bearing layer 3 is an underground original water-bearing layer. After coal mining, an open pit 300 is formed in the highwall, with a stripping bench 400 formed between adjacent layers.

The method for building the underground water storage system of the strip mine comprises the steps of forming the water storage system in the strip mine pit 300, and then backfilling and covering to form the underground water storage system hidden underground.

The invention provides a building method of an underground water storage system of a strip mine, which comprises the following construction steps:

first, the boundaries of the impoundment area 500 are determined based on the geographic location of the open pit mine, the depth, area of the open pit mine 300, and the like. The boundaries of the impoundment area 500 include vertically oriented upper and lower boundaries to define the depth of the impoundment area 500. The boundaries of the impoundment area 500 also include horizontal zone boundaries within a horizontal range to determine the lateral area of the impoundment area 500.

Specifically, the lower boundary of the end-wall aquifer 3 is used as the lower boundary of the impoundment area 500, the upper boundary of the impoundment area 500 can be flush with the upper boundary of the end-wall aquifer 3 according to the different thicknesses of the end-wall aquifer 3, the upper boundary of the impoundment area 500 can be lower than the upper boundary of the end-wall aquifer 3, and the upper boundary of the impoundment area 500 can be higher than the upper boundary of the end-wall aquifer 3.

The side highwall 200 and the rear highwall 100 are used as starting positions, and are offset from the open pit 300 within a horizontal range by a preset distance to serve as a horizontal region boundary of the impoundment area 500. The U-shaped impoundment area 500 can be closed as desired in a direction along the work line or in a direction along the side highwall 200 to form a closed impoundment area 500.

After the boundary of the impoundment area 500 is determined, an artificial water barrier 5 is constructed in the open pit 300 below the lower boundary of the impoundment area 500, wherein the artificial water barrier 5 is constructed in a manner of dumping into the open pit 300. The artificial water-resisting layer 5 is connected with the end upper water-resisting layer 2, and good water-resisting performance is achieved.

In the horizontal range, the area of the artificial water-resisting layer 5 is larger than the area of the water storage area 500, and the water storage area 500 is located in the boundary range of the artificial water-resisting layer 5, so that the water storage area 500 can be effectively prevented from being leaked downwards, and the water in the water storage area 500 is prevented from leaking downwards.

After the artificial isolation layer 5 is constructed, a main dam 6 is constructed above the artificial isolation layer 5, the main dam 6 surrounding the horizontal regional boundary of the impoundment area 500. The top surface of the main retaining dam 6 is higher than the upper boundary of the impoundment area 500, the bottom surface of the main retaining dam 6 is positioned in the artificial water-resisting layer 5, and the lower boundary of the main retaining dam 6 is lower than the lower boundary of the impoundment area 500, so that the impoundment area 500 is enclosed into a reservoir.

The main retaining dam 6 is constructed in a manner of dumping into the open pit 300, and the section of the main retaining dam 6 is trapezoidal, wide at the bottom and narrow at the top. On the one hand, the stability of the base is improved, and on the other hand, the water above is facilitated to be collected into the impoundment area 500 along the inclined surface of the main retaining dam 6.

When the main retaining dam 6 is constructed, the rear dam 61 may be constructed first, the side dams 62 may be constructed step by step with the advance of the open pit mine, and when the length of the side dams 62 meets the requirement (for example, 300m long), the front dam 63 may be constructed to close the impoundment area 500.

After the main retaining dam 6 is constructed, a rubble water collecting system 9 is constructed in the impoundment area 500, wherein the rubble water collecting system 9 comprises a plurality of rubble walls 91 arranged in a radial shape.

The rubble is stone with a particle size of more than 2 cm. The rubble catchment system 9 comprises a multi-faced rubble wall 91, the multi-faced rubble wall 91 is arranged radially from the middle to the outside of the impoundment area 500, for example, in a shape of a Chinese character 'mi'. Due to the large pores of the rubble, the peripheral water can be collected to the center of the impoundment area 500 more quickly.

The rubble water collecting system 9 is constructed by discharging rubbles into the water storage area 500, and stripped objects of strip mines are used as materials for building a reservoir and storing water, so that the sources are wide, the materials are convenient to take, and the cost is low.

After the rubble water collecting system 9 is constructed, a water storage body 10 is constructed between any two adjacent rubble walls 91. The water storage body 10 is composed of gravel with the grain diameter less than 2 cm.

The method specifically comprises the following steps: and discharging gravel between any two adjacent rubble walls 91 in an internal soil discharge manner to construct the water storage body 10. The water storage body 10 is discharged from the center of the surrounding water storage area 500 at the designed height for one time to reduce the compaction in the discharging process and improve the water storage effect.

The water storage body 10 is about 2-3m lower than the main retaining dam 6, so that water is prevented from flowing out of the top of the dam.

After the water storage body 10 is constructed, soil is discharged into the water storage area 500 in an internal soil discharge mode, and the rubble water collecting system 9 and the water storage body 10 are covered with surface soil, so that a hidden underground water storage system is formed.

The backfilling soil or the inner discharging soil can be backfilled to be as high as the upper layer 4 of the end upper or lower than the upper layer 4 of the end upper, and the backfilling soil or the inner discharging soil only covers the rubble water collecting system 9 and the water storage body 10.

Therefore, the construction method of the underground water storage system of the strip mine provided by the invention has the advantages that the underground water storage system is constructed by utilizing the earth discharge field in the strip mine, the space is abundant, the capacity is large, and the cost is low; the strip material of the strip mine is used as a material for building a reservoir and storing water, so that the strip mine has wide sources, convenient material taking and low cost; a rubble water collecting system and a water storage body formed by gravels are constructed in the water storage area, the water collecting effect is good, and the recycling efficiency of the stored water is improved.

In one embodiment, multiple underground water storage systems may be built at intervals in the strip mine advancing direction to meet the need for water transfer storage and time-shared retrieval in the strip mine pit 300.

In one optional technical scheme, the method for building the underground water storage system of the strip mine further comprises the following steps:

s7: the pumping hole 11, the filling hole 12 and the monitoring hole 13 are constructed from the top to the water storage area 500. Wherein, the water pumping hole 11 is positioned at the center of the rubble water collecting system 9, and the water injection hole 12 is positioned at one end of the rubble wall 91 far away from the center of the rubble water collecting system 9. The monitoring aperture 13 is located at the boundary of the water storage 10, i.e. the monitoring aperture 13 is located immediately inside the main water dam 6.

After the uppermost stripping step 400 of the dump is formed, the pumping hole 11 and the water injection hole 12 are constructed from top to bottom. The water pumping hole 11 is arranged in the center of the rubble water collecting system 9, and a stainless steel wire gauze is placed at the bottom to filter and seep water. A plurality of water injection holes 12 are formed at the periphery of the rubble water collecting system 9, and water can be injected into the water injection holes 12 to be stored in the water storage area 500. The water injection hole 12 can be used as a monitoring hole when not in operation. The monitoring hole 13 is arranged near the boundary of the water storage body 10 and is used for observing the water level of the water storage area 500 and ensuring that the water level does not exceed the water retaining dam. When the water level in the impoundment area 500 is higher than the alarm value, the water is discharged from the water pumping hole 11 by the water pumping pump.

In one embodiment, the method for constructing an underground water storage system of a strip mine further comprises the following steps: and auxiliary retaining dams 7 are built on the inner side and the outer side of the main retaining dam 6 in an internal soil discharge mode.

A main retaining dam 6 is constructed, and auxiliary retaining dams 7 are respectively constructed on the inner side and the outer side of the main retaining dam 6. And mud-rock materials or clay materials are discharged from two sides of the main retaining dam 6 to serve as an auxiliary retaining dam 7, the width of the upper part of the auxiliary retaining dam 7 is 1.5 times of the height of the upper boundary and the lower boundary of the impoundment area 500, and the slope gradient is between 20 and 25 degrees. The auxiliary retaining dam 7 plays a role in enhancing seepage prevention.

In one embodiment, the method for constructing an underground water storage system of a strip mine further comprises the following steps:

a plurality of vertically extending grouting holes are constructed into the main retaining dam 6, and the lower ends of the grouting holes extend into the artificial water-resisting layer 5. And injecting a cementing agent into the grouting hole.

And drilling a grouting hole downwards at the top of the main retaining dam 6, and injecting a cementing agent to plug the crack inside the main retaining dam 6 to form a watertight retaining dam. The grouting holes penetrate into the artificial water-resisting layer 5 by about 1-3 m, and the water-resisting effect is improved.

In one embodiment, the method for constructing an underground water storage system of a strip mine further comprises the following steps: the distance between two adjacent grouting holes is 1-1.5 times of the height of the main water retaining dam 6, and a complete warehouse body seepage-proofing system is favorably formed.

In one embodiment, the method for constructing an underground water storage system of a strip mine further comprises the following steps: high-level water-resisting layers 8 are constructed around the main retaining dam 6 in an internal dumping mode.

And (3) discarding the easy-to-bond mud rock materials within the range of 2-3m above the lower boundary of the water storage area 500 and repeatedly tamping the easy-to-bond mud rock materials to serve as a high-position water-resisting layer 8, wherein the thickness of the high-position water-resisting layer 8 is about 2 m. The high-position water-resisting layer 8 is positioned around the main water-retaining dam 6 and plays a role in preventing water from leaking outwards.

In one embodiment, the main dam 6 has a slope of between 20 ° and 25 ° to facilitate the collection of water into the impoundment area 500.

In one embodiment, the method for constructing an underground water storage system of a strip mine further comprises the following steps:

at the horizontal zone boundaries, the predetermined distance of offset into the open pit 300 is 5-7 times the average height of the endslope aquifer 3.

In the horizontal area boundary, the rear end slope 100 and the side end slope 200 are used as starting points, and the distance which is 5-7 times of the average height of the end slope aquifer 3 to the open pit 300 is used as the rear boundary and the two side boundaries of the water storage area 500, so that the underground water storage system does not influence the recovery of underground water conservancy relations after the open pit mining is finished.

In one embodiment, the method for constructing an underground water storage system of a strip mine further comprises the following steps:

when constructing the artificial water barrier 5:

and if the height of the constructed space is less than or equal to 10m, discharging the easily cemented mud rock material into the constructed space, and tamping the easily cemented mud rock material in a reciprocating manner by adopting an engineering vehicle.

If the height of the constructed space is more than 10m, firstly, the strippers (any waste) are discharged into the space which is less than 10m away from the lower boundary of the water storage area 500, then, the easily cemented mud rock materials are discharged into the space which is less than 10m away from the lower boundary of the water storage area 500, and the engineering vehicle is adopted for reciprocating tamping.

In one embodiment, the method for constructing an underground water storage system of a strip mine further comprises the following steps:

in determining the upper and lower boundaries of the impoundment area 500:

the upper and lower boundaries corresponding to the end slope aquifer 3 in the exposed strata of the end slope of the strip mine are selected to determine the upper and lower boundaries of the impoundment area 500.

If the height of the end upper aquifer 3 exceeds 45m, the lower boundary of the end upper aquifer 3 is used as the lower boundary of the impoundment area 500, and a plane which is 45m higher than the lower boundary of the end upper aquifer 3 is used as the upper boundary of the impoundment area 500.

If the height of the end-wall aquifer 3 is less than 30m, the lower boundary of the end-wall aquifer 3 is used as the lower boundary of the impoundment area 500, and a plane higher than the lower boundary 30m of the end-wall aquifer 3 is used as the upper boundary of the impoundment area 500.

If the height of the end upper aquifer 3 is greater than 30m and less than 45m, the lower boundary of the end upper aquifer 3 is used as the lower boundary of the impoundment area 500, and the upper boundary of the end upper aquifer 3 is used as the upper boundary of the impoundment area 500.

The height of the underground water storage system is coordinated with the open-air dumping operation and the stratum restoration of the dumping site, the requirement of water storage capacity is met, and the difficulty in dam construction is reduced as much as possible.

In conclusion, the method for constructing the underground water storage system of the strip mine provided by the invention has the advantages that the underground water storage system is constructed by utilizing the earth discharge field in the strip mine, so that the space is abundant, the capacity is large, and the cost is low; the strip material of the strip mine is used as a material for building a reservoir and storing water, so that the strip mine has wide sources, convenient material taking and low cost; a rubble water collecting system and a water storage body formed by gravels are constructed in the water storage area, the water collecting effect is good, and the recycling efficiency of the stored water is improved.

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.