阅读说明：本技术 一种适用于深度大于100m的贫水区露天矿地下水库的建设方法 (Construction method suitable for strip mine underground reservoir with depth larger than 100m in water-poor area ) 是由 陈树召 于 2021-07-27 设计创作，主要内容包括：本发明公开了一种适用于深度大于100m的贫水区露天矿地下水库的建设方法,包括如下步骤：S1：划定即将建设的储水区,在储水区一侧延伸出一条运输坡道,且坡道下方保留一段水平面,作地下水库使用；S2：在储水区的下表面及运输坡道表面铺设粘土层并机械压实,作为地下水库底部隔水层和挡水坝；S3：在非储水区排土工作线上,将其划分为排弃区和收集区；S4：建设地下水库过滤层；S5：从上部台阶向下排弃储水物料；S6：开设监测井和注水井,在监测井和抽水井内安装检测设备；S7：建设一道隔水挡墙；S8：开设抽水井、监测井和注水井。本发明方法缓解贫水区经济发展与水资源量的矛盾,有利于矿区扰动生态系统的恢复,施工难度小。(The invention discloses a construction method of an underground reservoir suitable for strip mines in a water-poor area with the depth of more than 100m, which comprises the following steps: s1: a water storage area to be built is defined, a transportation ramp is extended from one side of the water storage area, and a section of horizontal plane is reserved below the ramp and used as an underground reservoir; s2: paving clay layers on the lower surface of the water storage area and the surface of the transportation ramp and mechanically compacting the clay layers to serve as a water-resisting layer and a water-retaining dam at the bottom of the underground reservoir; s3: dividing the non-water storage area soil discharge working line into a discharge area and a collection area; s4: building a filtering layer of the underground reservoir; s5: draining the water storage material downwards from the upper step; s6: arranging a monitoring well and a water injection well, and installing detection equipment in the monitoring well and the pumping well; s7: constructing a water-resisting retaining wall; s8: and a pumping well, a monitoring well and a water injection well are arranged. The method of the invention relieves the contradiction between the economic development and the water resource amount of the water-poor area, is beneficial to the recovery of the disturbed ecosystem of the mining area and has small construction difficulty.)

1. A construction method suitable for an underground reservoir of a strip mine in a water-poor area with the depth of more than 100m is characterized by comprising the following steps:

s1: dividing an area around an original water-bearing layer (2) on one side, close to an end wall (1), of an earth dump in an open pit, defining a water storage area (3) to be built, wherein the length of the water storage area (3) is 1/5-1/4 of the length of a whole earth dumping working line, the lower surface of the water storage area (3) is flush with the lower surface of the original water-bearing layer (2), a step position below the lower surface of the water storage area (3) is used for dumping easily cemented mudstone materials with the thickness of 5-10m to serve as an artificial water-resisting layer (4), the artificial water-resisting layer (4) is connected with the original water-resisting layer (5) on two sides of the end wall (1), and the general waste of the open pit is discharged below the artificial water-resisting layer (4); a transportation ramp (6) for driving a truck is obliquely extended from bottom to top from the lower surface of one side of the water storage area (3), the gradient is 8-10%, a section of horizontal plane is reserved below the ramp and used as an underground reservoir, and the ramp and the bottom plane are compacted by equipment;

s2: paving clay layers of 3-5m on the lower surface of the water storage area (3) and the surface of the transportation ramp (6), and mechanically compacting the clay layers to serve as a water resisting layer (7) and a water retaining dam (8) at the bottom of the underground reservoir;

s3: on a soil discharging working line of the non-water storage area (3), the soil discharging working line is divided into a discharging area (9) and a collecting area (10), the length of each section is 200-300 m, a truck discharges materials with good water stability of gravel rocks in a segmented and alternative mode, grading formed by natural falling of the materials on a slope is utilized, and large materials at the slope angle of a step are collected and conveyed to the water storage area (3) to be discharged and used as water storage materials;

s4: constructing a fine granular glutenite or sand strip with the width 2-3 times of the height of an original water-bearing layer (2) on one side of the underground reservoir close to the side slope of the end slope (1) to be used as an underground reservoir filter layer (11);

s5: in the water storage area (3), water storage materials are discharged downwards from the upper step, natural separation of the materials is realized by utilizing the self gravity of the materials discharged from the high step, and gaps can be left among the materials for storing water;

s6: after the water storage materials are discharged to exceed the original aquifer (2), a monitoring well (12) and a water injection well (13) are arranged downwards from the surface of the water storage area (3), a water pumping well (14) is arranged outside the open pit end slope (1), detection equipment is arranged in the monitoring well (12) and the water pumping well (14) to know the water level in the reservoir, and the water level in the reservoir is controlled through the water injection amount and the water pumping amount;

s7: when the reservoir building length exceeds 20-30 times of the reservoir height, a water-resisting retaining wall (15) is built in the underground reservoir by utilizing clay or manually reinforced cementing treatment mudstone materials, and a water-retaining dam (8) built by a transportation ramp (6) in a stope is connected with an end slope (1) of an open pit;

s8: the pumping well (14) is arranged 20-30 m outside the side slope of the end slope (1), is excavated before the end slope (1) of the strip mine is exposed, and is also used as a dredging well, a side slope monitoring well (12) and the like; the monitoring wells (12) are arranged in the strip mine stope and outside the filter layer, and water injection is stopped when the monitoring wells (12) outside the underground reservoir segment rise in water level; when the water level of a monitoring well (12) in the underground reservoir section exceeds the warning water level, a pumping well (14) is forcibly started; the water injection well (13) which is not operated is also used as a monitoring hole to observe the water level change in the reservoir in the injection and extraction process; the water injection wells (13) are arranged at the center line of the section of the underground reservoir, 2-3 water injection wells are arranged in each section, and water injection is started from the water injection wells (13) far away from the strip mine stope.

2. The method for constructing an underground reservoir of an open pit mine suitable for a water-poor area with a depth of more than 100m as claimed in claim 1, wherein the water storage material discharge height in step S6 is 3-5m higher than the original aquifer (2).

3. The method for constructing an underground reservoir of a strip mine in a water-poor area with a depth of more than 100m as claimed in claim 2, wherein when the mine pit is rich in water during the mining of the strip mine, one underground reservoir is constructed at each of the two side walls (1) of the strip mine in step S1.

4. The method for constructing an underground reservoir of an open pit mine suitable for a water-poor region with a depth of more than 100m as claimed in claim 1 or 2, wherein the grain size of the bulk material at the slope in step S3 is more than 5 cm.

Technical Field

The invention particularly relates to a construction method of an underground reservoir suitable for strip mines in a water-poor area with the depth of more than 100m, and belongs to the field of coal mining.

Background

In the development process of large-scale strip mines, the integrity and continuity of underground aquifers can be damaged in the processes of crushing, disturbing and transferring stratum materials, and mine pit water gushing is generated, so that the normal production of the strip mines is influenced, the shortage of regional water resources is aggravated, and the water for ecological and industrial and agricultural production in mining areas is influenced. The water resources in inner Mongolia, Shanxi, Xinjiang, Gansu and other areas of China are deficient, underground water resources are released by the development of large-scale open-pit mines, and the contradiction between regional water resource supply and economic development is further aggravated if the underground water resources are not stored or utilized. Therefore, in order to meet the requirements of mineral resource development and national economic development in water-poor areas, a method for storing pit water by utilizing the stope space and stripping materials of strip mines is urgently needed to be developed.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a method for constructing an underground reservoir of an open-pit mine in a water-poor area with the depth of more than 100m, so as to solve the problem

In order to achieve the purpose, the invention adopts the technical scheme that:

a construction method of an underground reservoir suitable for strip mines in a water-poor area with the depth of more than 100m comprises the following steps:

s1: dividing an area around an original water-bearing layer on one side, close to an end slope, of an earth dump in the strip mine, and defining a water storage area to be built, wherein the length of the water storage area is 1/5-1/4 of the length of the whole earth dump working line, the lower surface of the water storage area is flush with the lower surface of the original water-bearing layer, steps below the lower surface of the water storage area are used for discarding easy-cementing shale materials with the thickness of 5-10m as an artificial water-resisting layer, the artificial water-resisting layer is connected with the original water-resisting layers on two sides of the end slope, and general waste of the strip mine is discarded below the artificial water-resisting layer; a transportation ramp for truck driving is obliquely extended from the lower surface of one side of the water storage area from bottom to top, the gradient is 8-10%, a section of horizontal plane is reserved below the ramp and used as an underground reservoir, and the ramp and the bottom plane are compacted by equipment;

s2: paving clay layers of 3-5m on the lower surface of the water storage area and the surface of the transportation ramp, and mechanically compacting the clay layers to serve as a water resisting layer and a water retaining dam at the bottom of the underground reservoir;

s3: on a soil discharging working line of a non-water storage area, dividing the soil discharging working line into a discharging area and a collecting area, wherein the length of each section is 200-300 m, a truck alternately discharges materials with good water stability of gravel rocks in a segmented manner, and large materials at a step slope angle are collected and transported to the water storage area to be discharged as water storage materials by utilizing grading formed by natural falling of the materials on a slope;

s4: constructing a fine-particle glutenite or sand strip with the width 2-3 times of the height of an original aquifer on one side of the underground reservoir close to the end slope, and using the fine-particle glutenite or sand strip as a filtering layer of the underground reservoir;

s5: in the water storage area, water storage materials are discharged downwards from the upper step, natural separation of the materials is realized by utilizing the self gravity of the materials discharged from the high step, and gaps can be reserved among the materials for storing water;

s6: after the water storage materials are discharged to exceed the original aquifer, a monitoring well and a water injection well are arranged downwards from the ground surface of the water storage area, a water pumping well is arranged outside the end side of the open pit mine, detection equipment is arranged in the monitoring well and the water pumping well, the water level in the reservoir is known, and the water level in the reservoir is controlled through the water injection amount and the water pumping amount;

s7: when the construction length of the reservoir exceeds 20-30 times of the height of the reservoir, constructing a water-proof retaining wall in the underground reservoir by using clay or manually reinforced cementing-treated mudstone materials, and connecting the end wall of the strip mine with a water retaining dam constructed by a transportation ramp in a stope;

s8: the pumping well is arranged 20-30 m outside the end slope, is excavated before the end slope of the strip mine is exposed, and is used as a dredging well, a slope monitoring well and the like; the monitoring wells are arranged in the strip mine stope and outside the filter layer, and water injection is stopped when the water level of the monitoring wells outside the underground reservoir segment rises; forcibly starting the pumping well when the water level of the monitoring well in the underground reservoir section exceeds the warning water level; the water injection well which is not operated is also used as a monitoring hole to observe the water level change in the reservoir in the injection and extraction process; the water injection well is arranged at the center line of the section of the underground reservoir, 2-3 water injection wells are arranged in each section, and water injection is started from holes far away from a strip mine stope.

Preferably, the water storage material discharge height in the step S6 is 3-5m higher than the original water storage layer height.

Preferably, when the pit water is abundant during the mining of the strip mine, an underground reservoir is built at each of the two side walls of the strip mine in step S1.

Preferably, the particle size of the bulk material at the slope in the step S3 is more than 5 cm.

The invention has the beneficial effects that:

(1) an underground reservoir is constructed by utilizing the stope space of the strip mine and the stripping materials, so that the storage and the utilization of pit water are realized, and the contradiction between the economic development of a water-poor area and the water resource amount is relieved.

(2) The materials for building the warehouse are preferably selected and processed in the transportation and dumping processes of the strippers, so that the cost is low and the production coordination is good.

(3) The underground reservoir is communicated with the near-surface aquifer, and the water level of the near-surface aquifer at the periphery is improved by utilizing the injected pit water meeting the requirements, so that the restoration of a mining area disturbance ecosystem is facilitated.

(4) The water taking wells are arranged at the periphery of the open pit, so that the construction difficulty is low, and underground water change caused by open pit mining can be monitored by using the water taking wells arranged in advance.

Drawings

Fig. 1 is a front view of a strip mine after construction of an underground reservoir;

FIG. 2 is a plan view of a strip mine after construction of an underground reservoir;

FIG. 3 is a top view of the installation of the monitoring well and the water injection well;

figure 4 is a cross-sectional view of the installation location of the monitoring well, the injection well and the suction well.

In the figure, 1-end slope, 2-original aquifer, 3-water storage area, 4-artificial water barrier, 5-original water barrier, 6-transportation ramp, 7-bottom water barrier, 8-water retaining dam, 9-dumping area, 10-collecting area, 11-underground reservoir filter layer, 12-monitoring well, 13-water injection well, 14-water pumping well and 15-water retaining wall.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

A construction method suitable for an underground reservoir of a strip mine in a water-poor area with the depth of more than 100m is characterized by comprising the following steps:

as shown in fig. 1 and 2, S1: dividing an area around an original water-bearing layer 2 on one side, close to an end wall 1, of a dumping ground in an open pit mine, defining a water storage area 3 to be built, wherein the length of the water storage area 3 is 1/5-1/4 of the length of a whole dumping working line, the lower surface of the water storage area 3 is flush with the lower surface of the original water-bearing layer 2, steps below the lower surface of the water storage area 3 are used for dumping easy-cementing shale materials with the thickness of 5-10m as an artificial water-resisting layer 4, the artificial water-resisting layer 4 is connected with the original water-resisting layers 5 on two sides of the end wall 1, and general dumping of the open pit mine is dumped below the artificial water-resisting layer 4; a transportation ramp 6 for truck driving is obliquely extended from the lower surface of the water storage area 3 to the bottom from the lower side, the gradient is 8-10%, a section of horizontal plane is reserved below the ramp and used as an underground reservoir, and the ramp and the bottom plane are compacted by equipment; the surface compactness and the water resistance of the discarded material are improved after compaction. When the mine pit water resources are rich in the process of mining the strip mine, an underground reservoir is built at each of the end walls 1 on the two sides of the strip mine, and the left side and the right side of the strip mine can be started to achieve double water storage capacity, so that the construction area is saved.

S2: paving clay layers of 3-5m on the lower surface of the water storage area 3 and the surface of the transportation ramp 6, and mechanically compacting the clay layers to serve as a water resisting layer 7 and a water retaining dam 8 at the bottom of the underground reservoir;

s3: on the soil discharging working line of the non-water storage area 3, the soil discharging working line is divided into a discharging area 9 and a collecting area 10, the length of each section is 200-300 m, the truck alternately discharges gravel rock materials with good water stability in a segmented mode, grading formed by natural falling of the materials on the slope is utilized, and large materials at the slope angle of the collecting step are conveyed to the water storage area 3 to be discharged and used as water storage materials. Preferably, the particle size of the large materials is larger than 5cm, the water storage efficiency of the materials with undersize particle sizes is not high, the excessive mixing can reduce the water storage capacity, but the materials with oversized particle sizes can increase the construction difficulty.

S4: constructing a fine granular glutenite or sand strip with the width 2-3 times of the height of an original water-bearing layer 2 on one side of the underground reservoir close to the side slope of the end wall 1 to serve as an underground reservoir filter layer 11;

s5: in the water storage area 3, water storage materials are discharged downwards from the upper step, natural separation of the materials is realized by utilizing the self gravity of the materials discharged from the high step, and gaps can be left among the materials for storing water;

s6: after the water storage materials are discharged to exceed the original water-bearing stratum 2, a monitoring well 12 and a water injection well 13 are arranged downwards from the surface of the water storage area 3, a water pumping well 14 is arranged outside the end wall 1 of the strip mine, detection equipment is arranged in the monitoring well 12 and the water pumping well 14, the water level in the reservoir is known, and the water level in the reservoir is controlled through the water injection amount and the water pumping amount; in order to achieve the best water storage efficiency and reduce the construction workload, the water storage material is discarded to a height 3-5m higher than the original water-bearing stratum 2, and the height can increase the water storage efficiency to the maximum efficiency on the basis of construction safety, and is the most preferable scheme.

S7: when the reservoir building length exceeds 20-30 times of the reservoir height, a water-resisting retaining wall 15 is built in the underground reservoir by utilizing clay or manually reinforced cementing processed mudstone materials, and the water-resisting retaining wall 8 is connected with the end wall 1 of the strip mine and the retaining dam 8 built by the transportation ramp 6 in the stope;

s8: the pumping well 14 is arranged 20-30 m outside the side slope of the end slope 1, is excavated before the end slope 1 of the strip mine is exposed, and is used as a dredging well, a side slope monitoring well 12 and the like; the monitoring wells 12 are arranged in the strip mine stope and outside the filter layer, and water injection is stopped when the water level of the monitoring wells 12 outside the underground reservoir segment rises; when the water level of the monitoring well 12 in the underground reservoir section exceeds the warning water level, the pumping well 14 is forcibly started; the water injection well 13 which is not operated is also used as a monitoring hole to observe the water level change in the reservoir in the injection and extraction process; the water injection well 13 is arranged at the center line of the section of the underground reservoir, 2-3 water injection wells are arranged in each section, and water injection is started from holes far away from a strip mine stope, as shown in figures 3 and 4.

The working principle of constructing the underground reservoir in the invention is as follows:

the pumping wells 14 are arranged in advance along the end slope 1 of the strip mine, so that underground water level changes in the production and soil discharge repairing processes of the strip mine can be monitored, the pumping wells 14 are started along with the construction of the underground reservoir and the improvement of the water level of the aquifer, and purified pit water is poured into the underground reservoir through the water injection wells 13. On the premise of ensuring that water in the underground reservoir does not flow back to the pit, continuously injecting water into the underground reservoir, ensuring that the water level in the dump is not higher than the designed height of the underground reservoir through the monitoring holes and the unused monitoring holes, starting the water suction pump according to the water requirement of the strip mine after the water suction well 14 monitors that the water level of the water-bearing layer outside the end slope 1 is obviously improved, and observing the water level change of the underground reservoir through the monitoring well 12 and the water injection well 13.