Adaptive surface pre-tightened coal mine anchor mesh support structure and its support method

Abstract

This invention provides an adaptive pre-tightened anchor mesh support structure and method for coal mines, belonging to the field of coal mine equipment. It includes: a cement blanket composite structure installed on the surrounding rock; multiple anchor cables, each passing through the cement blanket composite structure and inserted into the surrounding rock; and multiple anchor rods, each passing through the cement blanket composite structure and inserted into the surrounding rock. The cement blanket composite structure includes: a protective net installed on the rough excavation section of the surrounding rock; and a first cement blanket installed between the protective net and the rough excavation section of the surrounding rock. The purpose is to solve the problem of easy deformation and damage of protective nets in existing roadways. The achieved technical effect is a significant improvement in the overall efficiency of the support system.

Description

Technical Field

[0001] This invention relates to the field of coal mine equipment technology, and in particular to an adaptive surface pre-tightening coal mine anchor mesh support structure, and also to an adaptive surface pre-tightening coal mine anchor mesh support method. Background Technology

[0002] In coal mine roadway support systems, protective netting, as an important flexible surface protection component, plays an indispensable role in bolt support systems. Under bolt support, the application of protective netting enables a shift from point support to surface support for the roadway surface rock, significantly expanding the effective range of bolt prestressing. It effectively supports exposed rock strata between adjacent bolts, greatly enhancing the overall stability of the roadway surrounding rock and ensuring the smooth operation of coal mining. However, protective netting faces numerous severe challenges in practical applications. When exerting its support effect, its stress state is extremely complex, and its failure modes exhibit diverse characteristics. Deformation and failure of protective netting are commonplace in underground roadways, severely weakening the support effect and posing significant safety hazards to coal mine production. A more prominent problem is the poor adhesion of the protective netting, especially in newly excavated roadways with fractured surrounding rock, where numerous gaps exist between the netting and the rock. This results in the netting being unable to provide support to the surrounding rock in the initial stages of support, hindering the effective diffusion of anchor bolt prestress and limiting its passive support function, severely restricting the overall performance of the anchor bolt support system. Summary of the Invention

[0003] This invention provides an adaptive surface pre-tightening coal mine anchor mesh support structure and its support method, which solves the defects of existing protective mesh in roadways that are prone to deformation and damage, and achieves a significant improvement in the overall efficiency of the support system.

[0004] The first aspect of this invention provides an adaptive surface pre-tightening coal mine anchor mesh support structure, comprising: A cement blanket composite structure is installed on the surrounding rock; Anchor cables, there are multiple anchor cables, all of which are inserted into the surrounding rock through the cement blanket composite structure; Anchor bolts, there are multiple anchor bolts, all of which are inserted into the surrounding rock through the cement blanket composite structure; The cement blanket composite structure includes: Protective netting is installed on the rough cross-section of the surrounding rock during excavation; The first cement blanket is placed between the protective net and the rough section of the surrounding rock during excavation.

[0005] In addition, the adaptive surface pre-tightening coal mine anchor mesh support structure according to the present invention may also have the following additional technical features: In some embodiments of the present invention, the cement blanket composite structure further includes: The second cement blanket is installed on the side of the protective net that is away from the first cement blanket.

[0006] In some embodiments of the present invention, it further includes: The first cement blanket has a flexible hose installed on the side away from the protective net.

[0007] In some embodiments of the present invention, it further includes: Expansion support material is used to fill the gap between the first cement blanket and the surrounding rock.

[0008] In some embodiments of the present invention, it further includes: Expanding liquid was sprayed onto both the first and second cement blankets.

[0009] A second aspect of the present invention provides a method for adaptive surface pre-tightening of coal mine anchor mesh support, comprising the following steps: Step S100: Lay a cement blanket composite structure on the rough section of the tunnel; Step S200: Install anchor bolts and anchor cables to fix the cement blanket composite structure to the rough section of the tunnel; Step S300: Spray an expanding liquid onto the cement blanket composite structure to cause the cement blanket composite structure 1 to expand and extend; Step S400: Production complete.

[0010] In some embodiments of the present invention, step S100, laying the cement blanket composite structure on the rough section of the tunnel, includes the following steps: Step S110: Lay the first cement blanket on the rough section of the tunnel; Step S120: Lay a protective net on the side of the first cement blanket away from the tunneling anchor section; Step S130: Lay a second cement blanket on the side of the protective net that is away from the first cement blanket.

[0011] In some embodiments of the present invention, step S110, laying the first cement blanket on the rough section of the tunnel includes the following steps: Step S112: Inspect the roof and sidewall collapse at the rough end face of the tunnel; Step S114: Install a flexible hose on the side of the first cement blanket near the excavation section, according to the situation of roof collapse in the roadway.

[0012] In some embodiments of the present invention, step S200, fixing the cement blanket composite structure to the rough section of the tunnel by installing anchor bolts and anchor cables, includes the following steps: Step S210: Drill holes in both the cement blanket composite structure and the surrounding rock, and connect the holes in the cement blanket composite structure with the holes in the surrounding rock in a one-to-one correspondence. Step S220: Install the anchor bolts and anchor cables into the corresponding holes and pre-tighten them.

[0013] In some embodiments of the present invention, step S300: spraying an expanding liquid onto the cement blanket composite structure to cause the cement blanket composite structure to expand and extend includes the following steps: Step S310: Clean the surface dust of the cement blanket composite structure and spray the cement blanket composite structure with a first preset amount of expanding liquid to pre-wet it. Step S320: Spray a second preset amount of expanding liquid onto the cement blanket composite structure; Step S330: After the expanding liquid has penetrated, allow it to stand so that the cement blanket composite structure can expand and solidify naturally.

[0014] In summary, this application includes the following beneficial technical effects: Because cement blankets have the characteristics of increased strength and good expansion effect after being wetted, after laying the cement blanket composite structure and setting anchor bolts and cables for support, only water spraying is needed to completely wet the first cement blanket to apply active surface force to the protective net. Simultaneously, the anchor bolts and cables apply forces in opposite directions, thereby achieving automatic surface stress pre-tightening between the surrounding rock and the protective net, fully utilizing the active surface support function, and preventing deformation and damage to the protective net. It effectively compensates for the deficiency of traditional anchor net support in which the protective net cannot apply active prestress, promotes the coordinated operation of anchor support and surface support, and significantly improves the overall efficiency of the support system.

[0015] In addition, the cement blanket composite structure adheres tightly to the surrounding rock without leaving large gaps, effectively ensuring the adhesion performance of the protective net, which in turn promotes the effective diffusion of the anchor bolt prestress and ensures the stability and reliability of the support effect. Attached Figure Description

[0016] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 The diagram schematically shows a first view of an adaptive facet pre-tightened coal mine anchor mesh support structure connected to surrounding rock according to some embodiments of the present invention.

[0017] Figure 2 A second view schematically illustrates an adaptive facet pre-tightened coal mine anchor mesh support structure connected to surrounding rock according to some embodiments of the present invention.

[0018] Figure 3The diagram schematically shows a partially enlarged first view of an adaptive surface-preloaded coal mine anchor mesh support structure, according to some embodiments of the present invention, connected to the surrounding rock.

[0019] Figure 4 The diagram schematically shows a partially enlarged second view of an adaptive facet pre-tightened coal mine anchor mesh support structure connected to surrounding rock according to some embodiments of the present invention.

[0020] Figure 5 A first schematic diagram of an adaptive surface pre-tightened coal mine anchor mesh support structure according to some embodiments of the present invention is shown.

[0021] Figure 6 A second schematic diagram of an adaptive surface pre-tightened coal mine anchor mesh support structure according to some embodiments of the present invention is shown.

[0022] Figure 7 A third schematic diagram of an adaptive surface pre-tightened coal mine anchor mesh support structure according to some embodiments of the present invention is shown.

[0023] Figure 8 A fourth schematic diagram of an adaptive surface pre-tightened coal mine anchor mesh support structure according to some embodiments of the present invention is shown.

[0024] Figure 9 The fifth schematic diagram illustrates an adaptive surface pre-tightened coal mine anchor mesh support structure according to some embodiments of the present invention.

[0025] Figure 10 The diagram schematically illustrates the overall flow chart of the adaptive surface pre-tightening coal mine anchor mesh support method according to some embodiments of the present invention.

[0026] Figure 11 The flowcharts illustrating some embodiments of the adaptive surface pre-tightening coal mine anchor mesh support method of the present invention are shown in the diagram.

[0027] Figure label: 1. Cement blanket composite structure; 101. Protective net; 102. First cement blanket; 103. Second cement blanket; 2. Anchor cable; 3. Anchor rod; 4. Surrounding rock; 5. Hoses; 6. Expansion support material; 7. Overlap hole; 8. Expansion liquid; 9. Anchor; 10. Tunneling rough section. Detailed Implementation

[0028] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0029] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “” used herein may also indicate the inclusion of the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated, unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0030] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0031] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure is flipped, an element described as "below other elements or features" or "below other elements or features" would subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may also be rotated 90 degrees or in other orientations, and the spatial relative descriptors used in the text will be interpreted accordingly.

[0032] like Figures 1 to 9 As shown, according to an embodiment of the first aspect of the present invention, an adaptive surface pre-tightening coal mine anchor mesh support structure is proposed, including a cement blanket composite structure 1, anchor cables 2 and anchor rods 3. The cement blanket composite structure 1 is provided on the surrounding rock 4. There are multiple anchor cables 2, all of which pass through the cement blanket composite structure 1 and are inserted into the surrounding rock 4. There are multiple anchor rods 3, all of which pass through the cement blanket composite structure 1 and are inserted into the surrounding rock 4. The cement blanket composite structure 1 includes a first cement blanket 102 and a protective net 101. The first cement blanket 102 is disposed between the protective net 101 and the excavation rough section 10 of the surrounding rock 4.

[0033] In the above embodiments, it should be noted that there are multiple first cement blankets 102, and multiple first cement blankets 102 are laid sequentially on the excavation rough section 10 of the surrounding rock 4 and are initially fixed using anchor nails or expansion bolts; the protective net 101 is a metal mesh or fiber mesh, and multiple anchor rods 3 and multiple anchor cables 2 are arranged in a rectangular array, and also includes anchors 9. One end of each anchor rod 3 and each anchor cable 2 is connected to the protective net 101 through the anchors 9, and the other end of each anchor rod 3 and each anchor cable 2 is inserted into the surrounding rock 4.

[0034] The technical effects achieved by the above embodiments are as follows: Due to the characteristics of cement blankets increasing strength and having a good expansion effect after being wetted, after laying the cement blanket composite structure 1 and setting anchor rods 3 and anchor cables 2 for support, it is only necessary to spray water to completely wet the first cement blanket 102 to apply active surface force to the protective net 101. At the same time, the anchor rods 3 and anchor cables 2 apply forces in opposite directions, giving full play to the surface support function. This enables automatic surface stress pre-tightening between the surrounding rock 4 and the protective net 101, avoiding deformation and damage to the protective net. It effectively makes up for the defect that the protective net 101 cannot apply active prestress in traditional anchor net support, promotes the coordinated operation of anchor support and surface support, and greatly improves the overall efficiency of the support system.

[0035] In addition, the cement blanket composite structure 1 is tightly bonded to the surrounding rock 4 without large gaps, which effectively ensures the adhesion performance of the protective net 101, thereby promoting the effective diffusion of the prestress of the anchor bolt 3 and ensuring the stability and reliability of the support effect.

[0036] Optional, such as Figure 8 and Figure 9 As shown, the cement blanket composite structure 1 also includes a second cement blanket 103, and the second cement blanket 103 is provided on the side of the protective net 101 away from the first cement blanket 102.

[0037] In the above optional embodiments, it should be noted that there are multiple second cement blankets 103. After multiple second cement blankets 103 are laid flat on the protective net 101, they are initially fixed using anchor nails or expansion bolts.

[0038] The thickness of the second cement blanket 103 is less than the thickness of the first cement blanket 102.

[0039] The beneficial effects of the above optional embodiments are as follows: the combination of the second cement blanket 103 and the first cement blanket 102 achieves the following: the first cement blanket 102 has a large thickness and good water absorption and ductility, while the second cement blanket 103 has a small thickness and good water permeability. This allows water to quickly and completely penetrate the first cement blanket 102 and the second cement blanket 103 when workers spray water to expand them. This allows both the second cement blanket 103 and the first cement blanket 102 to expand quickly and reliably. The bidirectional expansion of the first cement blanket 102 and the second cement blanket 103 can maximize the protection of both sides of the protective net 101 by ensuring that the protective net 101 can fully exert its supporting function. At the same time, the anchor cable 2 and the anchor rod 3 can effectively fix the first cement blanket 102, the second cement blanket 103 and the protective net 101, maximizing the support performance and thus ensuring construction safety.

[0040] Optional, such as Figures 1 to 5 and Figure 7 As shown, it also includes a hose 5, and the first cement blanket 102 is provided with a hose 5 on the side away from the protective net 101.

[0041] In the above optional embodiments, it should be noted that the first cement blanket 102 may also be provided with an overlap hole 7 on the side away from the protective net 101, and the flexible hose 5 can be inserted into the overlap hole 7; the flexible hose 5 is a plastic flexible hose 5.

[0042] The advantages of the above optional embodiments are: by adding a flexible hose 5 to the first cement blanket 102, accurate and convenient water delivery can be achieved.

[0043] Water is supplied to the side of the first cement blanket 102 closest to the surrounding rock 4 through the hose 5, which ensures uniform and efficient watering, accelerates the hydration reaction of the first cement blanket 102, and quickly stimulates its strength growth and active force. Compared with the traditional water supply method, it effectively improves construction efficiency and support effect, and ensures that the support system is formed quickly and stably.

[0044] Optional, such as Figures 1 to 4 As shown, it also includes an expansion support material 6, and the gap between the first cement blanket 102 and the surrounding rock 4 is filled with the expansion support material 6.

[0045] In the above optional embodiments, it should be noted that the expansion support material 6 is delivered to the gap between the first cement blanket 102 and the surrounding rock 4 through the hose 5. The quick-setting expansion material can be a bonding adhesive, a gypsum-based quick-setting expansion material, a cement-based quick-setting expansion material, or a chemical grouting quick-setting expansion material. Preferably, the quick-setting expansion material is a cement-based quick-setting expansion material to increase its adhesion to the first cement blanket 102, thereby indirectly increasing the connection strength between the first cement blanket 102 and the surrounding rock 4.

[0046] The beneficial effects of the above optional embodiments are as follows: by setting the quick-setting expansion material, the bonding effect between the first cement blanket 102 and the excavation rough section 10 of the surrounding rock 4 can be guaranteed, and the depression of the surrounding rock 4 in the roadway can be filled to ensure good surface formation of the inner wall of the roadway.

[0047] Optional, such as Figure 2 and Figure 3 As shown, it also includes an expanding liquid 8, which is sprayed onto both the first cement blanket 102 and the second cement blanket 103.

[0048] In the above optional embodiments, it should be noted that the expanding liquid 8 can be water; the expanding liquid 8 can also be calcium sulfoaluminate, calcium oxide or metal expanding liquid 8.

[0049] The beneficial effects of the above optional embodiments are that the addition of the expanding liquid 8 enables both the first cement blanket 102 and the second cement blanket 103 to have a good expansion and curing effect.

[0050] According to an embodiment of the second aspect of the present invention, such as Figure 10 and Figure 11 As shown, an adaptive pre-tightened anchor mesh support method for coal mines is proposed, including the following steps: Step S100: Lay cement blanket composite structure 1 on the rough section 10 of the tunnel; Step S200: Install anchor bolts 3 and anchor cables 2 to fix the cement blanket composite structure 1 on the excavation rough section 10; Step S300: Spray expanding liquid 8 onto cement blanket composite structure 1 to cause cement blanket composite structure 1 to expand and extend; Step S400: Production complete.

[0051] In the above optional embodiments, it should be noted that in step S200, the method for installing anchor bolts 3 and anchor cables 2 is as follows: Hole positions are marked on the cement blanket composite structure 1. An anchor bolt 3 drilling rig is used to drill holes at the marked positions. The depth of the anchor bolt 3 hole must be 50mm to 100mm shorter than the length of the anchor bolt 3. The depth error of the anchor cable 2 hole is controlled within ±50mm. The drilling angle is perpendicular to the tunnel outline or constructed according to the design angle. After drilling, rock powder and accumulated water are cleaned from the hole. When installing anchor bolts 3, resin anchoring agent is fed into the bottom of the hole. After pushing it to the bottom of the hole with anchor bolt 3, it is rotated and stirred. After the anchoring agent solidifies, the nut is tightened. When installing anchor cables 2, the steel strand is first threaded into the drilled hole, and pre-tensioning is performed using a tensioning machine to ensure that the tension of anchor cables 2 reaches the design value. The anchoring end is fixed with high-strength anchoring agent or concrete to ensure a firm anchoring.

[0052] The advantages of the above optional embodiments are as follows: This method only replaces the laying of protective net 101 in the traditional anchor net support with a composite structure of laying cement blanket and protective net, and adds the process of spraying water source in the later stage after the support is completed; compared with the existing net back filling method, the process is simple and the operability is strong, so it has good on-site practicality.

[0053] Furthermore, in terms of support strength, this method utilizes the synergistic effect of the cement blanket composite structure 1, anchor bolts 3, and anchor cables 2 to form a rigid-flexible support system. After hardening, the cement blanket possesses high strength, providing initial support; the anchor bolts 3 and anchor cables 2 penetrate deep into the surrounding rock 4, connecting loose rock blocks to stable rock mass and enhancing the overall bearing capacity. After the injection of expanding liquid 8, the cement blanket expands in volume, filling the cracks on the rock surface, ensuring a tight fit between the support structure and the surrounding rock 4, reducing stress concentration, and further enhancing the support effect.

[0054] In terms of construction efficiency, cement blankets can be laid quickly, significantly shortening construction time compared to traditional concrete pouring; the spraying of expanding liquid 8 causes the cement blanket to extend rapidly, eliminating the need to wait for a long time to solidify and accelerating the construction progress.

[0055] In terms of safety, the expanded cement blanket can effectively seal the surrounding rock 4, preventing rockfall and gas leakage; its waterproof properties can reduce the softening effect of groundwater on the surrounding rock 4, maintain tunnel stability, and reduce the risk of collapse. At the same time, this method is simple to operate, reducing the time workers spend working at heights and exposed to hazardous environments for extended periods, thus ensuring the safety of construction personnel.

[0056] Optional, such as Figure 10 and Figure 11 As shown, step S100, laying the cement blanket composite structure 1 on the rough tunnel section 10 includes the following steps: Step S110: Lay the first cement blanket 102 on the rough section 10 of the tunnel; Step S120: Lay a protective net 101 on the side of the first cement blanket 102 away from the tunneling anchor section; Step S130: Lay a second cement blanket 103 on the side of the protective net 101 that is away from the first cement blanket 102.

[0057] In the above optional embodiments, it should be noted that the method for laying the first cement blanket 102 includes, Before laying, the rough cross-section 10 of the excavation is cleaned to remove debris such as loose stones and rock fragments; the first cement blanket 102 is cut into a shape suitable for the size of the rough cross-section. To ensure close contact with the base layer, an appropriate overlap allowance can be reserved according to the unevenness of the cross-section; during laying, the cement blanket is spread out from the top of the cross-section from top to bottom.

[0058] The method for laying the protective netting 101 includes cutting the protective netting 101 according to the rough cross-sectional dimensions to cover the entire surface of the first cement blanket 102. During laying, the protective netting 101 is laid flat on the side of the first cement blanket 102 opposite to the tunneling anchor section. Anchor nails or wire are used to fix the protective netting 101, ensuring the fixing points are evenly distributed and the spacing is not too large, guaranteeing that the protective netting 101 is flat, taut, and without any looseness. The overlap length between protective netting sections should be no less than 15 cm and securely tied with wire to ensure the integrity and stability of the protective netting 101, effectively fulfilling its role in reinforcing the structure. The method for laying the second cement blanket 103 includes laying the second cement blanket 103 after the protective net 101 is fixed; cutting the second cement blanket 103 according to the actual size, and laying it in a similar manner to the first cement blanket 102, starting from the top and laying it downwards to cover the entire surface of the protective net 101.

[0059] In step 300, after the expanding liquid 8 is sprayed onto the cement blanket composite structure 1 to cause the cement blanket composite structure 1 to expand and extend, the expansion of the cement blanket composite structure 1 is inspected. The specific inspection method includes: Before spraying, a reference grid is marked on the surface of the second cement blanket 103 using a steel needle or waterproof ink. After spraying the expanding liquid 8, the expansion area is scanned using a three-dimensional laser to obtain point cloud data. The scanned data is compared with the reference grid to calculate the expansion displacement of each point and the overall expansion rate. The average expansion rate needs to reach 90%-110% of the design value. The local expansion rate deviation should be ≤±3% to avoid excessive local expansion.

[0060] Expansion rate calculation formula: ; L0 is the length before injection, and L1 is the stable length after injection.

[0061] Stress waves can also be generated on the surface of the second cement blanket 103 by an ultrasonic transducer. The pressure distribution of the internal protective net 101 can be inverted by wave velocity. The pressure distribution of the protective net 101 is compared with the preset pressure distribution. When the measured pressure deviation exceeds the design value by 20%, it is determined that there is an anomaly.

[0062] When the measured pressure deviation is less than 20% of the design value, it meets the requirements. At this point, the self-adaptive pre-tightened coal mine anchor mesh support structure is completed.

[0063] The advantages of the above optional embodiments are as follows: the first cement blanket 102 adheres to the rough section 10 of the tunnel and solidifies quickly to form a basic protective layer; the protective net 101 enhances the overall tensile and shear strength and limits crack propagation; the second cement blanket 103 further seals and protects, improving the structure's impact resistance and wear resistance; thereby effectively resisting the pressure of the surrounding rock 4 and blasting vibration, reducing the shedding of loose particles, improving construction safety and durability, significantly improving the reinforcement effect compared to a single protective layer, and being easy to construct, which can speed up the project progress and reduce maintenance costs.

[0064] Optional, such as Figure 10 and Figure 11 As shown, in step S200, fixing the cement blanket composite structure 1 to the excavation rough section 10 by installing anchor bolts 3 and anchor cables 2 includes the following steps: Step S210: Drill holes in both the cement blanket composite structure 1 and the surrounding rock 4, and connect the holes on the cement blanket composite structure 1 with the holes on the surrounding rock 4 in a one-to-one correspondence. Step S220: Install the anchor rod 3 and anchor cable 2 into the corresponding holes and pre-tighten them.

[0065] In the above optional embodiments, it should be noted that the anchor cable 2 and anchor rod 3 are pre-tightened by using an anchor plate or nut.

[0066] Each hole penetrates the first cement blanket 102, the second cement blanket 103, and the protective net 101.

[0067] The advantages of the above optional embodiments are as follows: by driving the anchor rod 3 and the anchor cable 2 into the corresponding holes and pre-tightening them, the cement blanket composite structure 1 can be initially fixed. After the first cement blanket 102 and the second cement blanket 103 expand and solidify, the anchor rod 3 and the anchor cable 2 can be completely tightened, thereby ensuring the firmness and tightening reliability of the anchor cable 2 and the anchor rod 3.

[0068] Optional, such as Figure 10 and Figure 11 As shown, step S110, laying the first cement blanket 102 on the rough excavation section 10 includes the following steps: Step S112: Inspect the roof and sidewall collapse at the rough end face of the tunnel; Step S114: Based on the situation of roof collapse in the roadway, install the flexible hose 5 on the side of the first cement blanket 102 near the excavation rough section 10.

[0069] In the above optional embodiments, it should be noted that in step S114: according to the situation of roof collapse in the roadway, the flexible hose 5 is installed on the side of the first cement blanket 102 near the excavation rough section 10. The situation of roof collapse in the roadway includes no roof collapse and roof collapse, partial roof collapse, large-area roof collapse and large-area roof collapse, etc. In locations without roof collapse or partial roof fall, there is no need to install hoses 5 on the first cement blanket 102. Cement pipes are introduced into the first cement blanket 102 at locations with partial roof collapse or partial roof fall for the injection of expansion support material 6. In locations with large-area roof collapse or partial roof fall, the first layer of cement blanket is laid first, and then multiple hoses 5 are introduced into the second layer of the first cement blanket 102 before the second layer of the first cement blanket 102 is laid on top of the first layer of cement blanket.

[0070] The beneficial effects of the above optional embodiments are as follows: the installation of the flexible hose 5 on the side of the first cement blanket 102 near the excavation rough section 10 according to the roadway collapse situation is realized. This method can inject the corresponding expansion support material 6 according to the roadway collapse situation to achieve comprehensive support and protection of the roadway and ensure construction safety.

[0071] Optional, such as Figure 10 and Figure 11 As shown, in step S300: spraying expanding liquid 8 onto the cement blanket composite structure 1 causes the cement blanket composite structure 1 to expand and extend, including the following steps: Step S310: Clean the surface dust of the cement blanket composite structure 1 and spray the first preset amount of expansion liquid 8 to pre-wet the cement blanket composite structure 1. Step S320: Spray a second preset amount of expanding liquid 8 onto the cement blanket composite structure 1; Step S330: After the expanding liquid 8 has penetrated, let it stand to allow the cement blanket composite structure 1 to expand and solidify naturally.

[0072] In the above optional embodiments, it should be noted that the first preset amount of expansion liquid 8 is less than the second preset amount of expansion liquid 8.

[0073] The advantages of the above optional embodiments are: pre-wetting after cleaning surface dust can remove impurities that hinder the penetration of the expansion liquid 8, making it easier for the subsequently sprayed expansion liquid 8 to enter the interior of the cement blanket and improve the penetration effect.

[0074] Spraying the second preset amount of expansion liquid 8 and allowing it to stand and solidify allows the cement blanket composite structure 1 to fully expand and extend, effectively filling internal pores and fine cracks in the excavation rough section 10, improving density and integrity.

[0075] The expanded cement blanket composite structure 1 can fit more tightly into the rock wall, enhance the restraint of the surrounding rock 4, improve the bearing capacity and deformation resistance, effectively resist the influence of external forces such as ground stress and blasting vibration, and reduce the risk of roof collapse in the roadway.

[0076] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for adaptive surface pre-tightening of coal mine anchor mesh support, characterized in that, The support method is based on an adaptive surface pre-tightened coal mine anchor mesh support structure, the support structure comprising: A cement blanket composite structure (1) is set on the surrounding rock (4); Anchor cable (2), there are multiple anchor cables (2), and multiple anchor cables (2) are inserted into the surrounding rock (4) through the cement blanket composite structure (1); Anchor bolts (3), there are multiple anchor bolts (3), and multiple anchor bolts (3) are inserted into the surrounding rock (4) through the cement blanket composite structure (1); The cement blanket composite structure (1) includes: A protective net (101) is installed on the rough section (10) of the surrounding rock (4); The first cement blanket (102) is placed between the protective net (101) and the excavation section (10) of the surrounding rock (4); The cement blanket composite structure (1) also includes: The second cement blanket (103) is provided on the side of the protective net (101) away from the first cement blanket (102). The support method includes the following steps: Step S100: Lay a cement blanket composite structure (1) on the rough section (10) of the tunnel. Step S200: Install anchor bolts (3) and anchor cables (2) to fix the cement blanket composite structure (1) on the excavation rough section (10); Step S300: Spray expanding liquid (8) onto the cement blanket composite structure (1) to cause the cement blanket composite structure (1) to expand and extend; Step S400: Production complete; In step S100, laying the cement blanket composite structure (1) on the rough tunnel section (10) includes the following steps: Step S110: Lay the first cement blanket (102) on the rough section (10) of the tunnel. Step S120: Lay a protective net (101) on the side of the first cement blanket (102) away from the excavation rough section (10). Step S130: Lay a second cement blanket (103) on the side of the protective net (101) away from the first cement blanket (102). In step S300: spraying expanding liquid (8) onto the cement blanket composite structure (1) to cause the cement blanket composite structure (1) to expand and extend includes the following steps: Step S310: Clean the surface dust of the cement blanket composite structure (1) and spray the first preset amount of expansion liquid (8) to pre-wet the cement blanket composite structure (1). Step S320: Spray a second preset amount of expanding liquid (8) onto the cement blanket composite structure (1). Step S330: After the expanding liquid (8) has penetrated, let it stand so that the cement blanket composite structure (1) naturally expands and solidifies.

2. The adaptive surface pre-tightening coal mine anchor mesh support method according to claim 1, characterized in that, In step S110, a first cement blanket (102) is laid on the rough section (10) of the tunnel. Includes the following steps: Step S112: Inspect the roof and sidewall collapse situation of the tunnel at the rough cross-section; Step S114: Install a flexible hose (5) on the side of the first cement blanket (102) near the excavation rough section (10) according to the situation of roof collapse in the roadway.

3. The adaptive surface pre-tightening coal mine anchor mesh support method according to claim 1, characterized in that, In step S200, installing anchor bolts (3) and anchor cables (2) to fix the cement blanket composite structure (1) on the excavation rough section (10) includes the following steps: Step S210: Drill holes in both the cement blanket composite structure (1) and the surrounding rock (4), and connect the holes on the cement blanket composite structure (1) with the holes on the surrounding rock (4) in a one-to-one correspondence. Step S220: Install the anchor rod (3) and anchor cable (2) into the corresponding holes and pre-tighten them.

4. The adaptive surface pre-tightening coal mine anchor mesh support method according to claim 1, characterized in that, The support structure also includes: The hose (5) is provided on the side of the first cement blanket (102) away from the protective net (101).

5. The adaptive surface pre-tightening coal mine anchor mesh support method according to claim 1, characterized in that, The support structure also includes: The expansion support material (6) is used to fill the gap between the first cement blanket (102) and the surrounding rock (4).

6. The adaptive surface pre-tightening coal mine anchor mesh support method according to claim 1, characterized in that, The support structure also includes: The expanding liquid (8) is sprayed onto both the first cement blanket (102) and the second cement blanket (103).

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