Roadway composite spraying layer structure and roadway structure with same

Abstract

The utility model provides a roadway composite spraying layer structure and a roadway structure with the roadway composite spraying layer structure. According to the roadway composite spraying layer structure, a roadway is provided with a plurality of notches, and the roadway composite spraying layer structure comprises a first spraying layer sprayed on the surface of surrounding rock of the roadway to be used for filling the notches, and the surface, away from the surface of the surrounding rock, of the first spraying layer is a preset surface; the second spraying layer is sprayed on the preset surface; wherein the surface, connected with the preset surface, of the second spraying layer is a first surface, the surface, deviating from the preset surface, of the second spraying layer is a second surface, and the preset surface, the first surface and the second surface are all planes. The supporting structure effectively solves the problem that a supporting structure in the prior art cannot meet the supporting requirement.

Description

Technical Field

[0001] The utility model relates to the technical field of surface support and protection of surrounding rocks of underground tunnels in coal mines, and in particular to a tunnel composite spraying layer structure and a tunnel structure having the same. Background Art

[0002] At present, the spray protection of the surrounding rock surface of underground coal mine tunnels usually adopts the traditional shotcrete technology (dry spraying or wet spraying). However, the above spraying technology has the following defects:

[0003] (1) The construction environment is polluted by dust, the construction rebound is large, the amount of materials used is too large, resulting in tight auxiliary transportation and high labor intensity for construction workers;

[0004] (2) The supporting spraying equipment is bulky and inconvenient to move, the spraying layer hardens slowly, and the tensile strength of the hardened spraying layer is low, which makes the spraying layer prone to cracking, collapse or net bag phenomenon;

[0005] (3) The adhesion between the sprayed layer and the coal rock surface is poor, which leads to defects such as easy degassing and falling of the sprayed layer.

[0006] To sum up, for a long time, the surface support and protection effect of the surrounding rock of underground tunnels in coal mines has not only been unsatisfactory, but also requires a large amount of manpower and financial resources every year to implement tunnel renovation and repair work. There are also many tunnel surrounding rocks that cannot be sprayed and protected in time, resulting in erosion of the anchoring parts of the anchor rods and anchor cables in the tunnels, and the local anchoring force is gradually weakened or even lost, which directly affects the reliability of the overall support system of the tunnel anchor rods, causing stress concentration in local parts of the tunnel, resulting in safety accidents such as the collapse of the tunnel roof or deformation of the tunnel wall, seriously affecting the safety of underground operations.

[0007] In the prior art, in order to solve the above problems, the existing patent proposes to adopt a "sandwich" three-layer support structure, that is, the first layer is a 3.5-4.5 cm wet sprayed concrete layer, the second layer is a 0.2-1 mm organic thin sprayed material layer and the third layer is a 2.5-3.5 cm PP fiber modified polymer concrete layer, so as to ensure the good support performance and anti-seepage performance of the surface support structure of the deep well tunnel under the large dynamic pressure.

[0008] However, the above-mentioned "sandwich" three-layer support structure has several problems:

[0009] (1) The construction process of the three-layer structure is relatively complicated. The extensive application of the three-layer structure in underground tunnels can easily lead to the outermost PP fiber concrete layer (2.5-3.5 cm) not being easy to adhere to the second layer of 0.2-1 mm organic thin spray material layer due to inappropriate construction time, resulting in slow construction progress, difficulty in controlling the overall construction quality, and failure to realize the overall function of the support structure.

[0010] (2) The thickness of the intermediate thin organic spray layer is only 0.2 to 1 mm, which only plays a certain role in sealing and anti-seepage performance, but cannot play the role of the surrounding rock deformation and anti-plastic deformation ability.

[0011] (3) The "sandwich" support structure adopted by this technology relies on the strength of the two layers of concrete for its overall support strength. In fact, the tensile strength of concrete materials, even PP fiber-modified polymer concrete materials, is relatively low, less than 2 MPa, and the ultimate tensile strength, i.e., tensile deformation capacity, is very small, less than 1% or less than 0.1%. It is simply unable to adapt to the larger deformation under the influence of the dynamic pressure of the underground tunnel. The deformation of the tunnel affected by the dynamic pressure of the underground tunnel is at least about 10% or more.

[0012] (4) Although the support structure has good support strength and anti-seepage capacity for the tunnel surrounding rock, its ability to restrain the plastic deformation of the tunnel surrounding rock under the influence of underground dynamic pressure is poor. Utility Model Content

[0013] The main purpose of the utility model is to provide a tunnel composite spraying layer structure and a tunnel structure having the same, so as to solve the problem that the supporting structure in the prior art cannot meet the supporting requirements.

[0014] In order to achieve the above-mentioned purpose, according to one aspect of the utility model, a composite spray layer structure for a tunnel is provided, wherein the tunnel has multiple gaps, including: a first spray layer, sprayed on the surrounding rock surface of the tunnel to fill the gaps, and the surface of the first spray layer away from the surrounding rock surface is a preset surface; a second spray layer, sprayed on the preset surface; wherein the surface of the second spray layer connected to the preset surface is the first surface, and the surface of the second spray layer away from the preset surface is the second surface, and the preset surface, the first surface and the second surface are all planes.

[0015] Furthermore, the first sprayed layer is made of high-strength fine sand mortar and the particle size of the fine sand is less than 0.3 mm.

[0016] Furthermore, the thickness of the first sprayed layer is greater than or equal to 20 mm and less than or equal to 50 mm.

[0017] Furthermore, the second spray layer is made of high-toughness polymer fine sand mortar, the particle size of the fine sand is less than 0.3mm; and / or the content of polymer emulsion or polymer redispersible powder is greater than or equal to 40%; and / or the polymer-ash-to-material ratio is greater than or equal to 0.5.

[0018] Furthermore, the thickness of the second sprayed layer is greater than or equal to 10 mm and less than or equal to 20 mm.

[0019] Further, the compressive strength of the first sprayed layer is greater than or equal to 30 MPa; and / or the shear strength of the first sprayed layer is greater than or equal to 5 MPa.

[0020] Further, the tensile strength of the second sprayed layer is greater than or equal to 5 MPa; and / or the flexural and shear strengths of the second sprayed layer are greater than or equal to 5 MPa.

[0021] Further, the tensile strain at break of the second sprayed layer is greater than or equal to 10%; and / or the bonding strength of the second sprayed layer is greater than or equal to 3 MPa.

[0022] Furthermore, the first spray layer is sprayed by a pneumatic screw grouting pump; and / or the second spray layer is sprayed by a pneumatic screw grouting pump.

[0023] According to another aspect of the utility model, a tunnel structure is provided, comprising the above-mentioned tunnel composite spraying structure.

[0024] By applying the technical solution of the utility model, the tunnel composite spraying structure includes a first spraying layer and a second spraying layer, wherein the first spraying layer is sprayed on the surrounding rock surface of the tunnel to fill the gap, and the surface of the first spraying layer away from the surrounding rock surface is a preset surface. The second spraying layer is sprayed on the preset surface. Among them, the surface of the second spraying layer connected to the preset surface is the first surface, and the surface of the second spraying layer away from the preset surface is the second surface, and the preset surface, the first surface and the second surface are all planes. In this way, the first spray layer fills and seals the defects (such as gaps) on the surface of the consolidated surrounding rock on the side facing the surrounding rock surface, and the side of the first spray layer facing away from the surrounding rock surface is a preset surface (flat surface). The second spray layer is covered on the preset surface (flat surface) of the first spray layer, and the two realize a composite spray layer support structure with an effective combination of "rigidity and toughness", which effectively inhibits the plastic deformation of the surrounding rock of the underground tunnel, ensures the reliability of the anchor support system for the surrounding rock of the tunnel affected by the underground dynamic pressure, improves the overall safety of the surrounding rock of the tunnel, and effectively solves the problems of shotcrete in underground tunnels of coal mines being easily pulled under the influence of dynamic pressure due to insufficient tensile strength and flexural strength, and being easily cracked or netted due to folding and shearing.

[0025] Compared with the shotcrete (dry or wet) spraying layer in the prior art, the tunnel composite spraying layer structure in the present application realizes a composite spraying layer structure for rapid closure and consolidation of the surrounding rock surface and coordinated support that is efficient, green and pollution-free and adaptable to dynamic pressure changes, thereby solving the problem that the support structure in the prior art cannot meet the support needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings constituting part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0027] Figure 1 A schematic structural diagram of an embodiment of a tunnel composite spraying structure according to the utility model is shown;

[0028] Figure 2 Shows Figure 1 An enlarged schematic diagram of the composite spraying structure of the tunnel at point A.

[0029] The above drawings include the following reference numerals:

[0030] 10. Tunnel; 11. Gap; 12. Surrounding rock;

[0031] 20. First spray layer; 21. Preset surface;

[0032] 30. Second spray layer; 31. First surface; 32. Second surface. DETAILED DESCRIPTION

[0033] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present utility model will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0034] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0035] In the present invention, unless otherwise specified, directional words such as "up" and "down" are usually used in reference to the directions shown in the drawings, or in reference to the vertical, perpendicular or gravity direction; similarly, for ease of understanding and description, "left" and "right" are usually used in reference to the left and right shown in the drawings; "inside" and "outside" refer to the inside and outside relative to the outline of each component itself, but the above directional words are not used to limit the present invention.

[0036] In order to solve the problem that the supporting structure in the prior art cannot meet the supporting requirements, the present application provides a tunnel composite spraying layer structure and a tunnel structure having the same.

[0037] like Figure 1 and Figure 2 As shown, the tunnel 10 has a plurality of gaps 11, and the tunnel composite spray layer structure includes a first spray layer 20 and a second spray layer 30. The first spray layer 20 is sprayed on the surface of the surrounding rock 12 of the tunnel 10 to fill the gaps 11, and the surface of the first spray layer 20 away from the surface of the surrounding rock 12 is the preset surface 21. The second spray layer 30 is sprayed on the preset surface 21. Among them, the surface of the second spray layer 30 connected to the preset surface 21 is the first surface 31, and the surface of the second spray layer 30 away from the preset surface 21 is the second surface 32, and the preset surface 21, the first surface 31 and the second surface 32 are all planes.

[0038] By applying the technical solution of this embodiment, the first spray layer 20 fills and seals the defects (such as gaps) on the surface of the consolidating surrounding rock on the side facing the surrounding rock surface, and the side of the first spray layer 20 facing away from the surrounding rock surface is a preset surface 21 (flat surface). The second spray layer 30 is covered on the preset surface 21 (flat surface) of the first spray layer 20, and the two realize a composite spray layer support structure with an effective combination of "rigidity and toughness", which effectively suppresses the plastic deformation of the surrounding rock of the underground tunnel, ensures the reliability of the anchor support system for the surrounding rock of the tunnel affected by the underground dynamic pressure, improves the overall safety of the surrounding rock of the tunnel, and effectively solves the problem that the shotcrete in the underground tunnel of the coal mine is easily pulled under the influence of dynamic pressure due to insufficient tensile strength and flexural strength, and is easily cracked or netted due to folding and shearing.

[0039] Compared with the shotcrete (dry or wet) spraying layer in the prior art, the tunnel composite spraying layer structure in this embodiment realizes a composite spraying layer structure for rapid closure and consolidation of the surrounding rock surface and coordinated support that is efficient, pollution-free, and adaptable to dynamic pressure changes, thereby solving the problem that the support structure in the prior art cannot meet the support needs.

[0040] Optionally, the first spray layer 20 is made of high-strength fine sand mortar and the particle size of the fine sand is less than 0.3 mm. In this way, the above-mentioned setting enables the inner layer of the tunnel composite spray layer structure to adopt a high-strength ultra-fine mortar bottom spray layer, so as to quickly seal, consolidate and support the surface of the surrounding rock of the coal mine tunnel through the first spray layer 20. It not only has a good tunnel surface support capacity, but also has an effective ability to restrain the plastic deformation of the tunnel surrounding rock under dynamic pressure. At the same time, the above-mentioned setting makes the first spray layer 20 free of concrete gravel coarse aggregate, and the slurry penetrates into the irregular gaps and loose rock block gaps on the surface of the tunnel surrounding rock better than concrete, effectively repairing surface defects.

[0041] In this embodiment, the high-strength ultra-fine mortar bottom spraying layer easily penetrates into the cracks of the surrounding rock, plays an effective cementing role in the surface defects of the surrounding rock, and then fills and repairs the structural defects such as unevenness, surface crushing and local holes on the surface of the tunnel surrounding rock, such as the cracks of the crushed surrounding rock, local hole defects, and the cavity where the anchor tray is incompletely in contact with the surrounding rock surface. Figure 2 As shown, the first spray layer 20 is filled into the gaps, holes and other defects on the side facing the surrounding rock 12. At the same time, the first spray layer 20 is used to form a relatively flat surface on the surface of the tunnel surrounding rock due to its large thickness and high compressive shear strength, providing favorable conditions for the later spraying of the second spray layer 30 and the formation of a complete and tough composite spray layer structure.

[0042] Optionally, the material used for the first spray layer 20 is a high-strength ultrafine mortar material, including ultrafine silicate cement, refined fine sand with a particle size of less than 0.3 mm, special cement, basalt fiber, high-efficiency water reducer, thickener and other ingredients, with a water-to-material ratio of about 0.35. This mortar material can adhere well to an incompletely regular or uneven coal rock surface (such as the surrounding rock surface of a roadway).

[0043] Optionally, the thickness of the first spray layer 20 is greater than or equal to 20 mm and less than or equal to 50 mm. In this way, when the spray thickness of the first spray layer 20 is 20 to 50 mm, the high-strength ultra-fine mortar bottom spray layer reaches a compressive strength of more than 1 MPa after 0.5 hours of spraying, and a bonding strength of more than 2 MPa after 1 hour. The compressive strength reaches more than 10 MPa after 2 hours, and the compressive strength reaches more than 40 MPa after 7 days, thereby forming a complete and reliable bottom spray layer on the surrounding rock 12 of the tunnel.

[0044] It should be noted that the thickness of the first sprayed layer 20 refers to the thickness h of the thinnest area of ​​the coating formed by the first sprayed layer 20 on the surrounding rock surface. In the area where gaps and holes are filled, the depth of the bottom sprayed layer penetrating into the surrounding rock is not included in the measurement of this thickness.

[0045] Optionally, the second spray layer 30 is made of high-toughness polymer fine sand mortar, the particle size of the fine sand is less than 0.3 mm; and / or, the content of polymer emulsion or polymer redispersible powder is greater than or equal to 40%; and / or, the polymer-cement ratio is greater than or equal to 0.5. In this way, the high-toughness polymer ultra-fine mortar surface spray layer is sprayed on the surface of the high-strength ultra-fine mortar bottom spray layer to form a surface spray layer, which has excellent properties such as high compressive and tensile strength, good tensile deformation, strong adhesion, good flame retardancy and waterproofness.

[0046] Optionally, the high-toughness polymer ultrafine mortar material includes polymer emulsion or polymer redispersible powder (such as ethylene-vinyl acetate, acrylate, styrene-acrylate, etc.), ultrafine silica cement, special cement, polypropylene (PP) fiber, and thixotropic agent. Among them, the polypropylene fiber is evenly dispersed in the matrix to enhance the toughness of the surface spray layer structure and improve the tensile strength. The content of polymer emulsion or polymer redispersible powder is not less than 40%, and the polymer-cement-to-material ratio is not less than 0.5.

[0047] Optionally, the thickness of the second spray layer 30 is greater than or equal to 10 mm and less than or equal to 20 mm. In this way, the high-toughness polymer ultra-fine mortar surface spray layer sprayed on the bottom spray layer is sprayed with a thickness of 10 to 20 mm at a time, the top facade does not flow, can be hardened and strengthened relatively quickly, the surface drying time is less than 40 minutes, and the complete solidification time is less than 120 minutes. The tensile strength of the spray layer is greater than 5MPa, the flexural and shear strength is greater than 5MPa, the tensile deformation at break is greater than 10%, and the bonding strength is above 3MPa.

[0048] Optionally, the compressive strength of the first sprayed layer 20 is greater than or equal to 30 MPa; and / or the shear strength of the first sprayed layer 20 is greater than or equal to 5 MPa.

[0049] Optionally, the tensile strength of the second sprayed layer 30 is greater than or equal to 5 MPa; and / or the flexural and shear strengths of the second sprayed layer 30 are greater than or equal to 5 MPa.

[0050] Optionally, the tensile strain at break of the second sprayed layer 30 is greater than or equal to 10%; and / or the bonding strength of the second sprayed layer 30 is greater than or equal to 3 MPa.

[0051] Specifically, the composite spraying structure in this embodiment includes two layers of support structure: the first layer is a high-strength ultrafine mortar spraying layer with a thickness of 20 to 50 mm and a compressive strength greater than 25 MPa, and the second layer is a high-toughness polymer ultrafine mortar layer with a thickness of 10 to 20 mm, with a compressive strength greater than 10 MPa, a flexural strength greater than 5 MPa, a tensile strength greater than 5 MPa, and a tensile deformation greater than 10%. The composite structure is suitable for rapid sealing, consolidation and support and protection of the surface of the surrounding rock of coal mine tunnels. It not only has good tunnel surface support capabilities, but also has the ability to effectively constrain the plastic deformation of the tunnel surrounding rock under dynamic pressure.

[0052] Optionally, the first spray layer 20 is sprayed by a pneumatic screw grouting pump; and / or the second spray layer 30 is sprayed by a pneumatic screw grouting pump. In this way, the surface spray layer can be continuously constructed after the bottom spray layer is constructed, and the construction of the two spray layers does not require a special time interval, and the timely construction of the surface spray layer is conducive to the strength development of the bottom spray layer and the overall quality control.

[0053] In this embodiment, the inner layer of high-strength ultra-fine mortar bottom spray layer (first spray layer 20) and the outer layer of high-toughness polymer ultra-fine mortar surface spray layer (second spray layer 30) are indispensable, and together form a composite spray layer protection structure with excellent performance. If only the inner layer of high-strength mortar bottom spray layer is set, the entire spray layer material can play a certain role in sealing the tunnel surrounding rock, but the tensile strength of the spray layer is low, and it is easy to crack or break under the action of the large surrounding rock pressure, thereby losing the original protection function. At the same time, the mortar has poor deformation resistance (less than 0.1%), and it is easy to cause rupture and failure at a certain stress concentration position on the surface of the tunnel surrounding rock, thereby causing the overall support and protection function of the spray layer to be lost; and if only the outer layer of high-toughness polymer ultra-fine mortar surface spray layer is set, it will be difficult to achieve overall effective coverage of the underground tunnel surrounding rock surface irregular and large structural defects due to the insufficient coverage thickness of the tough surface spray layer, and it is difficult to achieve overall effective support reliability. If the thickness of the tough polymer ultra-fine mortar surface spray layer (the second spray layer 30) is increased, the economic cost will be too high and the value of promotion and application will be lost.

[0054] In this embodiment, the tunnel composite spraying layer structure combines the advantages of two materials, which not only ensures the good adhesion between the support and protection spraying layer and the surface of the coal rock mass, but also solves the problem of poor support and protection effect of the shotcrete spraying layer. Moreover, the spraying layer is thin as a whole, uses less material, and the comprehensive economic cost is quite low, which greatly reduces the large amount of manpower and financial costs required for annual renovation of underground tunnels due to poor support and protection effects. At the same time, it also effectively reduces the safety hazards of underground tunnels due to poor support and protection, and avoids safety accidents that may be caused by tunnel renovation. Its indirect social benefits are also very obvious, and it has a good prospect for promotion and application.

[0055] like Figure 1 As shown, the present application also provides a tunnel structure, including the above-mentioned tunnel composite spraying structure.

[0056] Specifically, the surface of the tunnel surrounding rock is directly sprayed and covered with a high-strength ultra-fine mortar bottom spray layer to fill and repair structural defects such as unevenness, surface breakage and local holes on the tunnel surrounding rock surface, and the holes between the anchor tray and the surrounding rock are filled and covered to form a support and protection bottom layer of a certain thickness; then a high-toughness polymer ultra-fine mortar surface spray layer with high tensile strength and good tensile properties is used to cover the bottom spray layer, so that the entire spray layer protection structure has the characteristics of combining "rigidity and toughness".

[0057] Its mechanism of action is as follows:

[0058] (1) Load-bearing shell function: The high-toughness polymer ultra-fine mortar spray layer forms a support structure of a certain thickness located on the surface of the surrounding rock. There are two ways to bear external loads: one is the "load-bearing arch" whose own structure bears lateral and longitudinal pressures, and the other is that it forms a "load-bearing basket" for loose blocks due to its own deep-seated rock cracks to form anchors. Due to the strong tensile strength and ductility of the tough spray layer, the "load-bearing basket" has a greater effect.

[0059] (2) Bonding effect: It includes two aspects. The high-strength ultra-fine mortar bottom spray layer can easily penetrate into the cracks of the surrounding rock, playing an effective bonding role for the surface defects of the surrounding rock. At the same time, the high-toughness polymer ultra-fine mortar surface spray layer has excellent tensile strength and deformation resistance, which ensures the synchronization of displacement between the surrounding rock and the spray layer under stress. Under the action of tensile and shear stress, the adhesion strength between the composite structure spray layer material and the rock mass and the tensile and shear strength of the composite spray layer itself are used to bond the cracks, thereby improving the cohesion of the joints. This reflects the modern support concept of the composite spray layer structure and the surrounding rock working together.

[0060] From the above description, it can be seen that the above embodiments of the utility model achieve the following technical effects:

[0061] The tunnel composite spraying structure includes a first spraying layer and a second spraying layer. The first spraying layer is sprayed on the surrounding rock surface of the tunnel to fill the gap. The surface of the first spraying layer away from the surrounding rock surface is the preset surface. The second spraying layer is sprayed on the preset surface. Among them, the surface of the second spraying layer connected to the preset surface is the first surface, and the surface of the second spraying layer away from the preset surface is the second surface. The preset surface, the first surface and the second surface are all planes. In this way, the first spray layer fills and seals the defects (such as gaps) on the surface of the consolidated surrounding rock on the side facing the surrounding rock surface, and the side of the first spray layer facing away from the surrounding rock surface is a preset surface (flat surface). The second spray layer is covered on the preset surface (flat surface) of the first spray layer, and the two realize a composite spray layer support structure with an effective combination of "rigidity and toughness", which effectively inhibits the plastic deformation of the surrounding rock of the underground tunnel, ensures the reliability of the anchor support system for the surrounding rock of the tunnel affected by the underground dynamic pressure, improves the overall safety of the surrounding rock of the tunnel, and effectively solves the problems of shotcrete in underground tunnels of coal mines being easily pulled under the influence of dynamic pressure due to insufficient tensile strength and flexural strength, and being easily cracked or netted due to folding and shearing.

[0062] Compared with the shotcrete (dry or wet) spraying layer in the prior art, the tunnel composite spraying layer structure in the present application realizes a composite spraying layer structure for rapid closure and consolidation of the surrounding rock surface and coordinated support that is efficient, green and pollution-free and adaptable to dynamic pressure changes, thereby solving the problem that the support structure in the prior art cannot meet the support needs.

[0063] Obviously, the embodiments described above are only some embodiments of the utility model, not all embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the utility model.

[0064] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0065] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0066] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A tunnel composite spraying structure, the tunnel (10) has a plurality of notches (11), characterized in that: include: A first spray layer (20) is sprayed on the surface of the surrounding rock (12) of the tunnel (10) to fill the gap (11), wherein the surface of the first spray layer (20) facing away from the surface of the surrounding rock (12) is a preset surface (21); A second spray layer (30) is sprayed on the preset surface (21); The surface of the second sprayed layer (30) connected to the preset surface (21) is the first surface (31), the surface of the second sprayed layer (30) away from the preset surface (21) is the second surface (32), and the preset surface (21), the first surface (31) and the second surface (32) are all planes.

2. The tunnel composite spraying structure according to claim 1 is characterized in that: The first sprayed layer (20) is made of high-strength fine sand mortar, and the particle size of the fine sand is less than 0.3 mm.

3. The tunnel composite spraying structure according to claim 1 is characterized in that: The thickness of the first sprayed layer (20) is greater than or equal to 20 mm and less than or equal to 50 mm.

4. The tunnel composite spraying structure according to claim 1 is characterized in that: The second spray layer (30) is made of high-toughness polymer fine sand mortar, and the particle size of the fine sand is less than 0.3 mm.

5. The tunnel composite spraying structure according to claim 1 is characterized in that: The thickness of the second sprayed layer (30) is greater than or equal to 10 mm and less than or equal to 20 mm.

6. The tunnel composite spraying structure according to claim 1 is characterized in that: The compressive strength of the first sprayed layer (20) is greater than or equal to 30 MPa; and / or the shear strength of the first sprayed layer (20) is greater than or equal to 5 MPa.

7. The tunnel composite spraying structure according to claim 1 is characterized in that: The tensile strength of the second sprayed layer (30) is greater than or equal to 5 MPa; and / or the flexural and shear strengths of the second sprayed layer (30) are greater than or equal to 5 MPa.

8. The tunnel composite spraying structure according to claim 1 is characterized in that: The tensile deformation at break of the second sprayed layer (30) is greater than or equal to 10%; and / or the bonding strength of the second sprayed layer (30) is greater than or equal to 3 MPa.

9. The tunnel composite spraying structure according to claim 1 is characterized in that: The first spray layer (20) is sprayed by a pneumatic screw grouting pump; and / or the second spray layer (30) is sprayed by a pneumatic screw grouting pump.

10. A tunnel structure, characterized in that: The invention comprises the tunnel composite spraying structure as claimed in any one of claims 1 to 9.

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