Mine underground wall surface structure

Abstract

The utility model discloses a mine underground wall surface structure, and belongs to the field of mine underground support. The mine underground wall surface structure comprises a surrounding rock base layer, a transition layer and a guniting layer which are sequentially stacked, and the transition layer is a siloxane layer. The mine underground wall surface structure is more stable in structure, good in supporting effect, capable of effectively preventing a surrounding rock base layer from falling off and weathering for a long time, and capable of effectively guaranteeing safe operation of a mine underground.

Description

Technical Field

[0001] This utility model relates to a wall structure for underground mines, belonging to the field of underground mine support. Background Technology

[0002] Shotcrete, as a key material for reinforcing surrounding rock and maintaining tunnels in underground mines, directly affects the stability and service life of the support system. Currently, shotcrete is typically sprayed directly onto the walls of mines to form a shotcrete layer, aiming to reinforce the wall surface (surrounding rock base), prevent wall weathering, and prevent accidents such as collapse or injury caused by falling sand and gravel. Currently, shotcrete used in mines is mostly composed of cementing materials (such as cement), aggregates (such as ordinary sand, tailings, slag, etc.), mixed with water. Due to the significant differences in physical properties (expansion coefficient, elastic modulus) between the surrounding rock base (such as rock) and the shotcrete layer, the compatibility between the shotcrete layer and the underground surrounding rock base is insufficient. This easily leads to stress concentration at the interface, causing cracks, peeling, or even detachment of the shotcrete layer, severely affecting the support effect. Furthermore, water often seeps into the surrounding rock base in mines, easily damaging the interface between the shotcrete layer and the surrounding rock base, leading to detachment accidents.

[0003] Patent application CN110359927A discloses a composite spraying material for underground coal mines and its application method. By weight, the composite spraying material comprises 1-2 parts cement, 2-4 parts sand, 2-4 parts crushed stone, 0.05-5 parts alumina, 4-8 parts calcium carbonate, 0.07-3 parts sodium hydroxide, and 0.12-3 parts dry powder quick-setting agent. The application method involves mixing the above materials evenly to obtain a mixture, packaging the mixture in bags and transporting it to the working face of the underground mine roadway, mixing the mixture with water to obtain a slurry, and spraying the slurry onto the mine walls and ceiling.

[0004] Patent application CN119504195A discloses a method for preparing a heat-insulating and reinforcing material for shotcrete support in mine roadways. The method involves crushing and sieving cotton stalks, then drying them until their mass is constant; preparing an alkali activator solution composed of NaOH and Na2SiO3; mixing slag powder and fly ash to obtain a slag-ash mixture; then mixing the slag-ash mixture with the alkali activator solution in a solid-liquid mixture, adding 2-5% quartz sand; after stirring, adding 20-28% cotton stalks, 0.35-0.45% aluminum powder foaming agent, and an appropriate amount of foam stabilizer; and finally, preparing a heat-insulating and reinforcing material for shotcrete support in mine roadways with a water-cement ratio of (0.4-0.6):1. This material is sprayed onto the surface of the surrounding rock in the roadway using a shotcrete support method to reinforce and support the surrounding rock.

[0005] As can be seen, the above-mentioned existing technologies all involve directly spraying the grout onto the surface of the surrounding rock base to form a grout layer. The grout layer is prone to defects such as cracks and peeling due to insufficient compatibility with the surrounding rock base, which affects the support effect. Utility Model Content

[0006] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a more stable underground mine wall structure.

[0007] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows:

[0008] A mine underground wall structure includes a surrounding rock base layer, a transition layer and a shotcrete layer stacked sequentially. The transition layer is a siloxane layer with a thickness of 0.5-2.5 mm, and the shotcrete layer has a thickness of 3-5 mm.

[0009] Optionally, the thickness of the transition layer is 1-2 mm.

[0010] Optionally, the thickness of the sprayed layer is 3.5-4.5 mm.

[0011] Optionally, an aqueous solution of an aminosilane coupling agent is sprayed onto the surrounding rock base layer, and after drying, a siloxane layer is formed. During this process, the aminosilane coupling agent hydrolyzes to form a dense siloxane layer. Further, the aminosilane coupling agent is KH-550 (γ-aminopropyltriethoxysilane). Optionally, the concentration of the aqueous solution of the aminosilane coupling agent is 1-5 wt%, more preferably 2-3 wt%.

[0012] Optionally, the sprayed grout layer is a concrete layer. Common cementitious materials such as cement and solid waste-based cementitious materials (e.g., those described in CN117466556A, CN120136464A, CN120622826A, etc.) can be mixed with water and aggregates to form a sprayed grout, which is then sprayed to construct the concrete layer. Tailings can be used as aggregates to achieve the reuse of solid materials such as tailings.

[0013] Optionally, the concrete layer is a cement concrete layer.

[0014] Optionally, the wall surface includes one or more of the side walls and the top wall.

[0015] In this invention, a siloxane layer (a conventional structural layer, see CN109517383A) is placed between the surrounding rock base and the sprayed grout layer, forming a high-density transition layer. This effectively blocks the damage to the sprayed grout layer and the interfacial bonding between layers caused by moisture penetration from the surrounding rock base, and also reduces the erosion of the sprayed grout layer by corrosive ions in humid environments, thus contributing to improved long-term stability of the wall structure. Furthermore, the siloxane layer contains active groups such as silanol (-Si-OH) and siloxane (-Si-O-Si-), which help optimize the bonding force between the surrounding rock base and the sprayed grout layer, preventing interlayer delamination due to differences in physical properties and improving the stability of the wall structure. Simultaneously, the siloxane layer also acts as a transition and buffer, helping to inhibit the development of cracks caused by uneven stress between the surrounding rock base and the sprayed grout layer.

[0016] The underground wall structure of this utility model has the following beneficial effects: the structure is more stable, the support effect is good, it can effectively prevent the surrounding rock base from falling off and weathering for a long time, and can effectively ensure safe operation in the mine. Attached Figure Description

[0017] Figure 1 This is a cross-sectional structural diagram of a mine underground wall structure according to the present invention.

[0018] In the diagram, 1-surrounding rock base layer, 2-transition layer, 3-shotcrete layer. Detailed Implementation

[0019] The present invention will be described in detail below with reference to the embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other. For ease of description, the words "up," "down," "left," and "right" appearing below only indicate that they are consistent with the up, down, left, and right directions of the drawings themselves, and do not limit the structure.

[0020] See Figure 1 A mine underground wall structure includes a surrounding rock base layer 1, a transition layer 2, and a shotcrete layer 3 stacked sequentially. The transition layer 2 is a siloxane layer. The shotcrete layer 3 is a cement concrete layer. The thickness of the transition layer 2 is 1 mm. The thickness of the shotcrete layer 3 is 4 mm.

[0021] When applying this method (taking a mine roadway as an example), first spray an aqueous solution of aminosilane coupling agent (KH-550) with a concentration of 2.5wt% onto the surface of the surrounding rock base 1 of the mine roadway (i.e., the original wall surface of the mine roadway). After natural drying, a siloxane layer is formed. Then, spray a slurry onto the surface of the siloxane layer. After drying, a slurry layer 3 is formed, thus completing the construction of the above-mentioned underground wall structure in the mine.

[0022] The shotcrete material can be prepared by mixing water, cementitious materials (cement or solid waste-based cementitious materials), and aggregates (tailings) in a mass ratio of 19:24.3:56.7, or other existing shotcrete materials can be used.

[0023] The above embodiments should be understood as being used only to illustrate the present invention more clearly, and not to limit the scope of the present invention. After reading the present invention, any modifications of the present invention by those skilled in the art in various equivalent forms fall within the scope defined by the appended claims.

Claims

1. A mine wall structure, characterised in that, Comprise the surrounding rock base layer (1), transition layer (2) and guniting layer (3) stacked in turn, the transition layer (2) is siloxane layer, the thickness of the transition layer (2) is 0.5-2.5mm, the thickness of the guniting layer (3) is 3-5mm.

2. The underground mine wall structure of claim 1, wherein, The thickness of the transition layer (2) is 1-2mm.

3. The mine wall structure according to claim 1, wherein, The thickness of the guniting layer (3) is 3.5-4.5mm.

4. A mine wall structure according to any one of claims 1 to 3, characterised in that, The guniting layer (3) is concrete layer.

5. A mine wall structure according to claim 4, characterised in that, The concrete layer is cement concrete layer.

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