Method for reducing the impact of mine side slope landslides on underground workings

Abstract

The application provides a method for reducing the impact of mine side slope landslide on underground mine, which comprises the following steps: laying a lower ore sand layer on the bottom area of an open pit as a bottom surface in full coverage; laying a pile group shock isolation layer on the lower ore sand layer; laying an upper ore sand layer on the pile group shock isolation layer; and laying a slope toe gravel cushion layer at the slope toe of a potential landslide body. Through the relative sliding between the pile groups in the pile group shock isolation layer and the damping effect of the pile groups on the ore sand layer and the slope toe gravel cushion layer, the direction of the landslide impact force is changed, most of the impact is transmitted and converted from downward to horizontal, and the impact range is converted from the roof area of the stoping area to the relative slope toe.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of open-pit to underground mining, and in particular to a method for reducing the impact of a mine slope landslide on underground mining. BACKGROUND

[0002] The surface slope of an open-pit to underground mine generally has a potential landslide body. The landslide formed thereby usually occurs in a sudden form. After a long period of gestation, a large amount of energy is accumulated and released in a sudden manner, and the dynamic impact is extremely large. The impact force of the landslide on the pit bottom is transmitted through the overburden rock and roof rock mass, and finally acts on the underground roadway rock mass and its structure, which may cause great loss to the life and property of underground workers.

[0003] To reduce the impact of a slope collapse on an underground stope, a conventional technical method is to build a retaining wall or lay other retaining structures at the bottom of the slope where the potential landslide body is located (generally at the slope toe position). A stable structure is formed by the retaining structure and the bottom rock-soil body to resist the lateral impact force of the landslide on the retaining structure. However, this method requires that the retaining structure must be fixed in the soil or rock mass below the sliding zone. However, under the working condition of open-pit to underground mining, the problem of strong surface subsidence caused by underground mining occurs. The rock mass in the pit bottom range including the slope toe range collapses and subsides, which does not meet the requirements for building retaining walls and other retaining structures.

[0004] Another conventional method is to form an overburden rock on the pit bottom by collapsing the overburden rock or backfilling gravel in the stope area. However, the cushioning effect of the gravel overburden layer is limited, and most of the impact force of the landslide is still transmitted to the roof rock mass of the stope area through the gravel cushion, which does not fundamentally solve the problem and still poses a risk to underground engineering. SUMMARY

[0005] To solve the above technical problems, the present application provides a method for reducing the impact of a mine slope landslide on underground mining.

[0006] The method forms a buffer body by a pile group isolation layer, a sand layer and a slope toe gravel cushion. Through the relative sliding of the pile group inside the pile group isolation layer and the damping effect of the pile group, the sand layer and the slope toe gravel cushion, the direction of the impact force of the landslide is changed, and most of the impact is transmitted from below to horizontal transmission, and the impact range is converted from the roof area of the stope area to the relative slope toe.

[0007] To solve the above-mentioned application purposes, the technical solutions provided by the present application are as follows:

[0008] A method for reducing the impact of a mine slope landslide on underground mining, characterized in that it comprises:

[0009] The pit bottom area of the open-pit mine is used as the bottom surface, and a lower sand layer is laid on the bottom surface.

[0010] a pile group isolation layer is laid on the upper part of the lower sand layer;

[0011] an upper sand layer is laid on the pile group isolation layer;

[0012] a slope toe gravel cushion is laid at the slope toe of the potential landslide body.

[0013] Optionally, in the step of laying the slope toe gravel cushion at the slope toe of the potential landslide body, the slope toe gravel cushion covers at least a part of the upper sand layer.

[0014] Optionally, the pile group isolation layer comprises at least two layers of upper and lower pile groups, the upper pile group is above the lower pile group, the upper and lower pile groups form a layered structure, the central axis of each wood pile in the lower pile group is perpendicular to the landslide projection direction of the potential landslide body on the slope, and the central axis of each wood pile in the upper pile group is perpendicular to the central axis direction of the lower wood pile.

[0015] Optionally, the layer height of the upper and lower pile groups is in the range of 1-3 meters.

[0016] Optionally, the upper sand layer, the pile group isolation layer and the lower sand layer form a layered structure from top to bottom, and the layer thickness of the upper and lower sand layers is in the range of 8-20 meters.

[0017] Optionally, the slope toe gravel cushion is a slope-type gravel accumulation body, and the slope toe gravel cushion is laid at the slope toe and on the main landslide path of the potential landslide body.

[0018] Optionally, the overall height of the slope toe gravel cushion is in the range of 20-35 meters, and the inclination angle of the slope toe gravel cushion is less than 45°.

[0019] Optionally, the pile group isolation layer, the upper sand layer, the lower sand layer and the slope toe gravel cushion form a landslide damping structure, at least one set of the landslide damping structure is laid with the open-pit bottom area as the bottom surface, and each set of the landslide damping structure is stacked in a layered manner.

[0020] Optionally, the laying range of the landslide damping structure is determined according to at least one of the size, impact distance and underground mining area range of the potential landslide body in the mining area.

[0021] Optionally, the pile group isolation layer is composed of multiple layers of pile-type materials stacked in layers, each layer of the pile-type materials is placed in a perpendicular manner, and the pile-type materials are selected from any one or a combination of multiple materials such as dead wood piles, waste and old wood pile materials and waste synthetic wood according to the actual mine engineering.

[0022] In the above scheme, the deformation caused by the impact is concentrated on the pile group isolation layer through the upper ore sand layer and the slope toe gravel cushion layer, and by using the pile group isolation structure characteristics, the pile group rolls and slides in the ore sand layer during the impact process, dissipates the impact energy and changes the impact force propagation direction, so that most of the impact is transferred from the roof area of the mining area to the slope toe of the opposite side slope, effectively reducing the impact of the side slope landslide on the underground working area.

[0023] In the above scheme, the pit bottom subsidence is caused by the transition from open pit to underground, each group of landslide shock absorption structures is stacked in layers, and all the cushion layers sink with them, so the shock absorption damping effect is not affected by the mining subsidence, and the buffer capacity for landslide impact is not affected.

[0024] In some schemes, the landslide shock absorption structure material is easy to obtain and can be obtained locally, using waste rock, ore sand, rock and waste wood piles, without the need for additional construction of retaining walls and other supporting structures, the process is simple, avoiding the large cost of laying a large thickness of bulk material cushion caused by the consideration of engineering safety in traditional open pit to underground mines, and more safely and efficiently achieving the prevention and weakening of the impact force caused by potential slope landslide, while achieving the needs of safety and cost savings. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0026] Figure 1 Flowchart of a method for reducing the impact of mine slope landslide on underground according to the present application;

[0027] Figure 2 Schematic diagram of the landslide shock absorption structure in the present application;

[0028] Figure 3 For Figure 2 Cross-sectional view in A-A direction;

[0029] Figure 4 Structure schematic diagram of the pile group isolation layer in the present application;

[0030] Figure 5 Structure schematic diagram of the slope toe gravel cushion layer in the present application.

[0031] In which the reference signs are explained as follows:

[0032] 1, pile group isolation layer; 2, lower sand layer; 3, upper sand layer; 4, slope toe gravel cushion; 6, potential landslide body; 7, slope toe; 8, lower pile group; 9, upper pile group. DETAILED DESCRIPTION

[0033] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be described clearly and completely below with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the described embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art without any inventive effort fall within the scope of protection of the present application.

[0034] Unless otherwise defined, technical terms or scientific terms used in the present application shall have the usual meaning understood by a person of ordinary skill in the art to which the present application belongs. The similar words such as "one", "a" or "the" used in the present application also do not represent the quantity limitation, but represent the existence of at least one. The similar words such as "include" or "contain" mean that the elements or objects before the words cover the elements or objects listed after the words and their equivalents, without excluding other elements or objects.

[0035] The present application changes the direction of the landslide impact force by the relative sliding of the pile group in the pile group isolation layer and the damping effect of the pile group and the sand layer and the slope toe gravel cushion, so that most of the impact is transmitted from the bottom to the horizontal transmission, and the impact range is converted from the roof area of the stoping area to the relative slope toe. The materials of the pile group isolation layer, the sand layer and the slope toe gravel cushion are easy to obtain, can be obtained locally, and waste rock, sand, rock and waste wood piles are used. At the same time, no additional retaining wall and other supporting structures need to be built, the process is simple, the large cost consumption caused by laying a large thickness of bulk cushion for considering the engineering safety of the traditional open-pit to underground mine is avoided, and the prevention and weakening of the impact force caused by the potential slope landslide are more safely and efficiently realized, and the needs of ensuring safety and saving cost are realized.

[0036] In combination Figure 1 and Figure 2 The method for reducing the underground impact of the mine slope landslide provided by the present application comprises the following steps.

[0037] S100: laying a lower sand layer 2 on the bottom surface of the open-pit bottom area in full coverage;

[0038] S200: laying a pile group isolation layer 1 on the upper part of the lower sand layer;

[0039] S300: laying an upper sand layer 3 on the pile group isolation layer.

[0040] S400: The slope toe gravel cushion 4 is arranged at the slope toe 7 where the potential landslide body 6 is located.

[0041] In combination Figure 2 , it should be noted that the up-down direction refers to Figure 2 , the "up", "down" orientation terms and the like used herein only represent relative positional relationships, which may change accordingly when the absolute position of the described object changes. Here, all belong to the protection scope of the present application, in addition, it can be understood that when a layer, a region and the like are referred to as being located "on" or "under" another layer, the layer can be "directly" located "on" or "under" another layer or an intermediate layer can exist.

[0042] In combination Figure 2 , the materials required for the pile group isolation layer 1, the upper sand layer 3, the lower sand layer 2 and the slope toe gravel cushion 4 are determined in advance, the ground of the open pit bottom 5 area is leveled, the lower sand layer 2 is laid first, the pile group isolation layer is laid from far to near after tamping, the upper sand layer 3 is then naturally piled and arranged, and finally the slope-type slope toe gravel cushion 4 is piled and arranged at the slope toe 7 where the potential landslide body 6 is located.

[0043] The above scheme forms a buffer body through the pile group isolation layer 1, the upper sand layer 3, the lower sand layer 2 and the slope toe gravel cushion 4, changes the direction of the landslide impact force through the relative sliding of the pile group inside the pile group isolation layer 1 and the damping effect of the pile group and the sand layer and the slope toe gravel cushion, and converts most of the impact from downward transmission to horizontal transmission, and converts the impact range from the roof area of the stoping area to the relative slope toe 7.

[0044] In step S400, the slope toe gravel cushion 4 covers at least part of the upper sand layer 3.

[0045] In step S200, the pile group isolation layer 1 includes at least two layers of pile groups, i.e., an upper layer of pile groups and a lower layer of pile groups, the upper layer of pile groups is located above the lower layer of pile groups, the upper layer of pile groups and the lower layer of pile groups form an upper and lower layer structure, the central axis of each wood pile in the lower layer of pile groups is perpendicular to the landslide projection direction of the upper potential landslide body of the slope, and the central axis of each wood pile in the upper layer of pile groups is perpendicular to the central axis direction of each wood pile in the lower layer of pile groups.

[0046] In one embodiment, as Figure 3 , Figure 4As shown, the pile group isolation layer 1 is composed of two layers of pile materials, and the lower pile group 8 and the upper pile group 9 can be arranged in the divided areas at the same time, that is, a row of 1-2m lower pile group 8 is arranged at the bottom of the pit near the slope toe area, all the wood piles in the lower pile group 8 are arranged horizontally as much as possible, and the central axes of all the wood piles are perpendicular to the projection direction of the most dangerous potential landslide body 6 on the slope. Then, a plurality of upper pile groups 9 are stacked vertically on the lower pile group 8, and all the wood piles in the upper pile group 9 are arranged horizontally above the lower pile group 8 as much as possible, and the central axes of the upper wood piles are perpendicular to the central axes of the lower wood piles. In this way, all the potential impact ranges are gradually covered, and the pile materials are selected from any one of dry wood piles, waste wood pile materials, and waste synthetic wood or a combination of multiple materials.

[0047] In the above embodiment, the deformation caused by the impact is concentrated on the pile group isolation layer 1 by the upper sand layer 3 and the slope toe gravel cushion layer 4. During the impact process, the pile group rolls and slides in the sand layer to dissipate the impact energy and change the direction of the impact force propagation, so that most of the impact is transferred from the roof area of the mining area to the opposite slope toe 7, thereby effectively reducing the impact of the slope landslide body 6 on the underground working area.

[0048] In another embodiment, the height of the upper pile group 9 and the lower pile group 8 is in the range of 1m to 3m.

[0049] In combination with Figure 3 and Figure 4 , in some embodiments, the upper sand layer 3, the pile group isolation layer 1, and the lower sand layer 2 form a stacked structure from top to bottom, and the thickness of the upper sand layer 3 and the lower sand layer 2 is in the range of 8m to 20m.

[0050] In combination with Figure 3 , Figure 4 As shown, the sand layer is divided into an upper sand layer 3 and a lower sand layer 2, and the thickness can be in the range of 10-15m. The lower sand layer 2 is simply tamped after being laid, and the lower sand layer 2 can be directly laid without tamping to ensure that the pile group isolation layer 1 has a certain sliding and rolling space during loading. The sand material is selected from one or more combinations of waste sand and other small particle waste rocks.

[0051] In combination with the above embodiment, in combination with Figure 5 As shown, the slope toe gravel cushion layer 4 is a slope-type gravel accumulation body, and the slope toe gravel cushion layer 4 is laid at the slope toe 7 and is located on the main landslide path of the potential landslide body 6.

[0052] In combination with the above embodiment, the overall height of the slope toe gravel cushion layer 4 is in the range of 20m to 35m, and the inclination angle of the slope toe gravel cushion layer 4 is less than 45°.

[0053] The slope toe gravel cushion 4 is a slope type gravel accumulation body, the stacking range is at the slope toe of the open pit side slope 7 where the potential landslide 6 is located and is on the main landslide path of the potential landslide body 6, the overall height is 20-30 m, the inclination angle is less than 45°, the gravel material is composed of gravel blocks with a particle size of 0.2 m-0.5 m, and the gravel material is selected from one or more of waste rock, rock and the like.

[0054] The laying range of the pile group isolation layer 1, the upper mine sand layer 3, the lower mine sand layer 2 and the slope toe gravel cushion 4 can be determined comprehensively according to factors such as the size of the potential landslide body in the mining area, the impact distance and the range of the underground mining area.

[0055] In some embodiments, the pile group isolation layer 1, the upper mine sand layer 3, the lower mine sand layer 2 and the slope toe gravel cushion 4 are built into landslide damping structures, and at least one group of the landslide damping structures is laid with the open pit bottom area as the bottom surface, wherein each group of the landslide damping structures is built into a layered mutual stacking.

[0056] In the above embodiment, the open pit is converted into an underground pit, causing pit bottom subsidence, each group of the landslide damping structures is built into a layered mutual stacking, all the cushions sink, the damping and damping effect is not affected by the mining subsidence, and the buffering capacity for landslide impact is not affected.

[0057] In the above embodiment, the laying range of the landslide damping structure is determined according to at least one of the size of the potential landslide body 6 in the mining area, the impact distance and the range of the underground mining area.

[0058] In the above embodiment, the pile group isolation layer 1 is composed of a plurality of layers of pile type materials stacked in layers, the placement of each layer of the pile type material is perpendicular to each other, and the pile type material is selected from any one or more of dry wood piles, waste and old wood pile materials and waste synthetic wood according to the actual mine engineering.

[0059] In the above embodiment, the materials of the pile group isolation layer 1, the upper mine sand layer 3, the lower mine sand layer 2 and the slope toe gravel cushion 4 are easy to obtain and can be obtained locally, waste rock, mine sand, rock and waste and old wood piles are used, and no additional retaining wall and other supporting structures need to be built, the process is simple, the large cost consumption caused by laying a large thickness of the traditional open pit into an underground mine for engineering safety is avoided, and the prevention and weakening of the impact force caused by the potential slope landslide 6 is more safely and efficiently realized, and the needs of ensuring safety and saving cost are realized.

[0060] The following points need to be explained:

[0061] (1) The drawings of the embodiments of the present application only involve the structures involved in the embodiments of the present application, and other structures can be referred to the usual design.

[0062] (2) For clarity, the thickness of layers or regions in the drawings used to describe embodiments of the present application is exaggerated or reduced, i.e., the drawings are not drawn to scale.

[0063] (3) Embodiments of the present application and features in the embodiments can be combined with each other to obtain new embodiments, without conflict.

[0064] The above merely describes specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method of reducing the impact of a mine's side slope slippage on underground workings, characterised by, The application relates to a landslide damping structure. The landslide damping structure comprises: a lower ore sand layer laid on the bottom area of an open pit; a pile group damping layer laid on the lower ore sand layer; an upper ore sand layer laid on the pile group damping layer; a slope toe gravel cushion laid at the slope toe of a potential landslide body.

2. A method of reducing the impact of a mine's side slope landslide on an underground mine according to claim 1, characterized in that, The pile group damping layer comprises at least two layers of upper and lower pile groups, the upper pile group is located above the lower pile group, the upper and lower pile groups form an upper and lower layer structure, the central axis of each wood pile in the lower pile group is perpendicular to the landslide projection direction of the potential landslide body on the slope, and the central axis of each wood pile in the upper pile group is perpendicular to the direction of the central axis of the lower wood pile.

3. A method of reducing the impact of a mine's side slope landslide on an underground mine according to claim 1, characterized in that, The slope toe gravel cushion at least covers part of the upper ore sand layer.

4. A method of reducing the impact of a mine's side slope landslide on an underground mine according to claim 1, characterized in that, The layer height of the upper and lower pile groups is in the range of 1-3 meters.

5. A method of reducing the impact of a mine's side slope landslide on an underground mine according to claim 2, characterized in that, The upper ore sand layer, the pile group damping layer and the lower ore sand layer form a self-laminated structure from top to bottom, and the layer thickness of the upper and lower ore sand layers is in the range of 8-20 meters.

6. A method of reducing the impact of a mine's side slope slumping on underground workings according to claim 5 wherein, The slope toe gravel cushion is a slope-type gravel accumulation body, and is laid at the slope toe and on the main landslide path of the potential landslide body.

7. A method of reducing the impact of a mine's side slope landslide on an underground mine according to claim 1, characterized in that, The overall height of the slope toe gravel cushion is in the range of 20-35 meters, and the inclination angle of the slope toe gravel cushion is less than 45 degrees.

8. A method of reducing the impact of a mine's side slope slumping on underground workings according to claim 7, characterised in that, The pile group damping layer, the upper ore sand layer, the lower ore sand layer and the slope toe gravel cushion form a landslide damping structure, and at least one group of the landslide damping structure is laid on the bottom area of an open pit, wherein each group of the landslide damping structure is stacked in a layered manner.

9. A method of reducing the impact of a mine's side slope slumping on underground workings according to claim 7, characterised in that, The laying range of the landslide damping structure is determined according to at least one of the size, impact distance and underground mining area range of the potential landslide body. The pile group damping layer is composed of multiple layers of pile-type materials, each layer of the pile-type materials is arranged in a perpendicular manner, and the pile-type materials are selected from any one or a combination of dry wood piles, waste wood pile materials and waste synthetic wood according to the actual mine engineering.

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