Partitioned supporting method for roadway roof in water erosion environment

Abstract

The invention relates to the technical field of roadway support, and discloses a roadway roof partition support method in a water erosion environment, which comprises the following steps: determining the geological condition of a roadway roof in a geophysical prospecting mode, and carrying out detection analysis to obtain a detection analysis result; dividing the roadway roof into a strong water erosion area, a weak water erosion area and a non-water erosion area according to the detection analysis result; according to the detection analysis result, physical parameters of roadway roofs in the strong water erosion area, the weak water erosion area and the non-water erosion area are simulated and analyzed through a mathematical model, so that a supporting strategy is determined; selecting a supporting tool according to the supporting strategy; a supporting strategy of a weak water erosion area or a non-water erosion area adjacent to the strong water erosion area is firstly completed, and then a supporting strategy of the strong water erosion area is completed, so that supporting is completed; and arranging a real-time monitoring assembly to obtain a monitoring result in real time. Safety in the roadway roof supporting process is improved, damage of water erosion to the roadway roof is reduced, and the service life of a roadway is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of roadway support, and particularly relates to a method for sectional support of a roadway roof in a water erosion environment. Background Art

[0002] In underground mining engineering, a roadway is a passage dug for ore mining, transportation, ventilation, drainage, and personnel passage. Roadway support is a safety measure taken to enhance the stability of the surrounding rock of the roadway and prevent the deformation and collapse of the surrounding rock of the roadway due to reasons such as stress changes and geological tectonic movements. Roadway support often adopts support methods such as bolt support, shotcrete, grouting reinforcement, or a combination of multiple methods.

[0003] Water erosion refers to the erosion of soil and rock by hydraulic action, which will cause the destruction of the rock mass structure and the reduction of strength. Due to the water erosion effect, the physical and mechanical properties such as the tensile strength and cohesion of the surrounding rock will be significantly reduced, resulting in poor stability of the surrounding rock. At the same time, the water erosion environment will also accelerate the corrosion of roadway support materials and reduce their bearing capacity and durability. In the prior art, for roadway support in water-rich environments such as water erosion, high-corrosion-resistant support materials are mostly used.

[0004] The above-mentioned support methods are usually applicable to the conventional roadway roof conditions. Since in a water erosion environment, the roadway roof is prone to roof leakage, forming a roof fall area and a water inrush channel, which brings greater resistance to roadway support. Therefore, the traditional support methods are difficult to meet the support requirements of the roadway roof in a water erosion environment and are prone to safety accidents such as roof collapse. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a method for sectional support of a roadway roof in a water erosion environment.

[0006] The present invention provides a method for sectional support of a roadway roof in a water erosion environment, comprising the following steps: S1: Detect and analyze the geological conditions of the roadway roof through geophysical exploration methods to obtain the detection and analysis results, and the detection and analysis results at least include geological conditions, rock properties, and water erosion degree.

[0007] S2: Divide the roadway roof into a strong water erosion area, a weak water erosion area, and an un-eroded area according to the detection and analysis results.

[0008] S3: According to the detection and analysis results, use a mathematical model to simulate and analyze the physical parameters of the roadway roof in the strong water erosion area, the weak water erosion area, and the un-eroded area respectively to determine the support strategy, and the support strategy includes a support strategy for the strong water erosion area, a support strategy for the weak water erosion area, and a support strategy for the un-eroded area.

[0009] The support strategy for the strong water erosion area includes: determining the installation depth according to the rock formation conditions in the strong water erosion area, installing the anchor bolts into the roof of the roadway, injecting an anchoring agent with waterproof and anti-corrosion properties, arranging the anchor bolts in a plum blossom shape, laying an anchor net based on the anchor bolts, and spraying concrete on the metal net.

[0010] The support strategy for the weak water erosion area includes: determining the installation depth according to the rock formation conditions in the weak water erosion area, installing the anchor bolts into the roof of the roadway, injecting an anchoring agent with waterproof and anti-corrosion properties, and the spacing of the anchor bolts in the weak water erosion area is greater than that in the strong water erosion area, and laying a geogrid based on the anchor bolts.

[0011] The support strategy for the non-water erosion area includes: determining the installation depth according to the rock formation conditions in the non-water erosion area, and installing the anchor bolts into the roof of the roadway.

[0012] S4: Select support tools according to the support strategy: Select the first anchor bolt in the strong water erosion area, select the second anchor bolt in the weak water erosion area, and select the third anchor bolt in the non-corroded area.

[0013] S5: First complete the support strategy for the weak water erosion area or the non-water erosion area adjacent to the strong water erosion area, and then complete the support strategy for the strong water erosion area to complete the support.

[0014] S6: Arrange real-time monitoring components at intervals in the strong water erosion area, the weak water erosion area, and the non-water erosion area to obtain monitoring results in real time. The monitoring results at least include the displacement of the roadway roof, stress changes, leakage conditions, and the stress of the anchor bolts.

[0015] Optionally, the support strategy for the strong water erosion area further includes: arranging an auxiliary anode and an external power supply in the strong water erosion area to perform cathodic protection on the first anchor bolt.

[0016] Optionally, the metal net in the strong water erosion area is made of steel wires with a corrosion-resistant coating.

[0017] Optionally, the length of the first anchor bolt is greater than the length of the second anchor bolt, and the length of the second anchor bolt is greater than the conventional length.

[0018] Optionally, the distribution density of the first anchor bolt is greater than the distribution density of the second anchor bolt, and the distribution density of the second anchor bolt is greater than the distribution density of the third anchor bolt.

[0019] Optionally, a transition area metal net is laid between the transition area between the strong water erosion area and the weak water erosion area or between the strong water erosion area and the non-water erosion area, and concrete is sprayed on the transition area metal net.

[0020] Optionally, the laying direction of the transition area metal net forms an angle of 30° to 60° with the axis direction of the roadway.

[0021] Optionally, the laying direction of the geogrid forms an angle of 30° to 60° with the axis direction of the roadway.

[0022] Optionally, the first bolt includes a main bolt, and at least two expansion shell parts are arranged along the length direction of the main bolt.

[0023] Optionally, the detection and analysis result further includes the position of the rock stratum fissure on the roadway roof. Before implementing the support strategy for the strong water erosion area, use cement mortar or anchor agent to fill the rock stratum fissure.

[0024] The technical solution provided by the embodiment of the present invention has the following advantages compared with the prior art: A method for sectional support of a roadway roof in a water erosion environment provided by an embodiment of the present invention determines the geological conditions of the roadway roof through geophysical exploration for detection and analysis to obtain the detection and analysis results; divides the roadway roof into a strong water erosion area, a weak water erosion area, and an un-eroded area according to the detection and analysis results; according to the detection and analysis results, uses a mathematical model to simulate and analyze the physical parameters of the roadway roof in the strong water erosion area, the weak water erosion area, and the un-eroded area respectively to determine the support strategy; selects support tools according to the support strategy; first completes the support strategy for the weak water erosion area or the un-eroded area adjacent to the strong water erosion area, and then completes the support strategy for the strong water erosion area to complete the support; real-time monitoring components are arranged at intervals in the strong water erosion area, the weak water erosion area, and the un-eroded area to obtain the monitoring results in real time. It can take corresponding effective support measures according to the characteristics of different areas of the roadway roof in the water erosion environment, improve the safety during the support process of the roadway roof, improve the stability of the support of the roadway roof at the same time, reduce the damage of water erosion to the roadway roof, extend the service life of the roadway, and reduce the safety risks during the engineering construction process. Description of the Drawings

[0025] Figure 1 It is a flowchart of a method for sectional support of a roadway roof in a water erosion environment provided by an embodiment of the present invention. Detailed Embodiment

[0026] The following combines the drawings to describe a specific embodiment of the present invention in detail, but it should be understood that the protection scope of the present invention is not limited by the specific embodiment.

[0027] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the technical solutions of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0028] A roadway is a passage dug for ore mining, transportation, ventilation, drainage, and personnel access. Roadway support is a safety measure taken to enhance the stability of the surrounding rock of the roadway, preventing the deformation and collapse of the surrounding rock of the roadway due to stress changes, geological tectonic movements, etc. Roadway support often adopts support methods such as bolt support, shotcrete, grouting reinforcement, or a combination of multiple methods.

[0029] Water erosion refers to the erosion of soil and rock by hydraulic action, which can lead to the destruction of the rock mass structure and a reduction in strength. Due to water erosion, the physical and mechanical properties such as the tensile strength and cohesion of the surrounding rock will be significantly reduced, resulting in poor stability of the surrounding rock. At the same time, the water erosion environment will also accelerate the corrosion of roadway support materials, reducing their bearing capacity and durability. In the prior art, for roadway support in water-rich environments such as water erosion, high-corrosion-resistant support materials are mostly used.

[0030] Existing support methods are usually applicable to the conventional roadway roof conditions. Since in a water erosion environment, the roadway roof is prone to roof leakage, forming a roof fall area and a water inrush channel, which brings greater resistance to roadway support. Therefore, traditional support methods are difficult to meet the support requirements of the roadway roof in a water erosion environment and are prone to safety accidents such as roof collapse. For this reason, the embodiments of the present invention provide a method for sectional support of a roadway roof in a water erosion environment, which can take corresponding effective support measures according to the characteristics of different areas of the roadway roof in a water erosion environment, improve the safety during the support process of the roadway roof, improve the stability of the roadway roof support at the same time, reduce the damage of water erosion to the roadway roof, extend the service life of the roadway, and reduce the safety risks during the engineering construction process.

[0031] At least one embodiment of the present invention provides a method for sectional support of a roadway roof in a water erosion environment, including the following steps: S1: Determine and detect and analyze the geological conditions of the roadway roof through geophysical exploration methods to obtain the detection and analysis results, and the detection and analysis results at least include geological conditions, rock properties, and water erosion degree.

[0032] S2: Classify the roadway roof into a strong water erosion area, a weak water erosion area, and an un-eroded area according to the detection and analysis results.

[0033] S3: According to the detection and analysis results, use a mathematical model to simulate and analyze the physical parameters of the roadway roof in the strong water erosion area, the weak water erosion area, and the un-eroded area respectively to determine the support strategies, which include the support strategy for the strong water erosion area, the support strategy for the weak water erosion area, and the support strategy for the un-eroded area.

[0034] The support strategy for the strong water erosion area includes: determining the installation depth according to the rock formation conditions in the strong water erosion area, installing the anchor bolts into the roadway roof, injecting an anchoring agent with waterproof and anti-corrosion properties, arranging the anchor bolts in a plum blossom shape, laying an anchor mesh based on the anchor bolts, and spraying concrete on the metal mesh.

[0035] The support strategy for the weak water erosion area includes: determining the installation depth according to the rock formation conditions in the weak water erosion area, installing the anchor bolts into the roadway roof, injecting an anchoring agent with waterproof and anti-corrosion properties, and the spacing of the anchor bolts in the weak water erosion area is greater than that in the strong water erosion area, and laying a geogrid based on the anchor bolts.

[0036] The support strategy for the un-eroded area includes: determining the installation depth according to the rock formation conditions in the un-eroded area, and installing the anchor bolts into the roadway roof.

[0037] S4: Select support tools according to the support strategies: select a first anchor bolt with a tensile strength higher than that of carbon steel in the strong water erosion area and spray an anti-corrosion coating on the surface of the first anchor bolt, select a second anchor bolt with a tensile strength higher than that of carbon steel in the weak water erosion area, and select a third anchor bolt with a conventional material in the un-corroded area.

[0038] S5: First complete the support strategies for the weak water erosion area or the un-eroded area adjacent to the strong water erosion area, and then complete the support strategy for the strong water erosion area to complete the said support.

[0039] S6: Arrange real-time monitoring components at intervals in the strong water erosion area, the weak water erosion area, and the un-eroded area to obtain real-time monitoring results, and the monitoring results at least include the displacement of the roadway roof, stress changes, leakage conditions, and the stress of the anchor bolts.

[0040] In the above-described roadway roof zoning support method provided by the embodiments of the present invention, before supporting the roadway roof, the geological conditions of the roadway roof are detected and analyzed in detail, and the roadway roof is divided into a strong water erosion area, a weak water erosion area, and an uneffected water erosion area according to the degree of geological water erosion. Corresponding support strategies are formulated for different roof areas, and support tools used for different roof areas are selected accordingly. Therefore, corresponding effective support measures can be taken according to the characteristics of different areas of the roadway roof in a water erosion environment, improving the safety during the support process of the roadway roof, enhancing the stability of the roadway roof support, reducing the damage of water erosion to the roadway roof, extending the service life of the roadway, and reducing the safety risks during the engineering construction process.

[0041] The present invention will be described below through several specific embodiments. To keep the following description of the embodiments of the present invention clear and concise, the detailed description of known functions and known components may be omitted.

[0042] As Figure 1 shown, the embodiments of the present invention provide a roadway roof zoning support method in a water erosion environment, including the following steps: S1: Detect and analyze the geological conditions of the roadway roof through geophysical exploration methods to obtain the detection and analysis results, where the detection and analysis results at least include geological conditions, rock properties, and water erosion degree.

[0043] Specifically, before supporting the roadway roof, the geological conditions of the roadway roof are detected and analyzed through geophysical exploration methods (such as ground penetrating radar, drilling and coring, etc.), and the detection and analysis results are obtained. The detection and analysis results mainly include the geological conditions, rock properties, water erosion degree, and water volume distribution in the rock formation of the roadway roof, such as the stratigraphic distribution of the roadway roof, whether it is affected by water erosion, the distribution and damage conditions of the roof rock formation, the specific distribution position and water erosion depth of the rock formation eroded by water, and the fracture development conditions, etc.

[0044] The geological conditions of the roadway roof are understood first through the geophysical exploration analysis results, and then targeted support strategies are formulated according to the geological conditions of different areas.

[0045] S2: Divide the roadway roof into a strong water erosion area, a weak water erosion area, and an uneffected water erosion area according to the detection and analysis results; Specifically, the strong water erosion area is the area where the roof is severely affected by water erosion. In this area, the rock formation structure is highly damaged, the rock formation strength is low, and there may be fractures; the weak water erosion area is the area where the water erosion degree is relatively weak. In this area, the rock formation structure may be damaged to a certain extent, but the overall strength of the rock formation is relatively intact; the uneffected water erosion area is the area that is basically not affected by water erosion and has good rock formation integrity.

[0046] S3: According to the detection and analysis results, use mathematical models to simulate and analyze the physical parameters of the roadway roof in the strong water erosion area, weak water erosion area, and non-water erosion area respectively to determine the support strategies, including the support strategy for the strong water erosion area, the support strategy for the weak water erosion area, and the support strategy for the non-water erosion area.

[0047] The support strategy for the strong water erosion area includes: determining the installation depth according to the rock formation conditions in the strong water erosion area, installing the anchor bolts into the roadway roof, injecting anchor agents with waterproof and anti-corrosion properties, arranging the anchor bolts in a plum blossom shape, laying an anchor net based on the anchor bolts, and spraying concrete on the metal net.

[0048] The support strategy for the weak water erosion area includes: determining the installation depth according to the rock formation conditions in the weak water erosion area, installing the anchor bolts into the roadway roof, injecting anchor agents with waterproof and anti-corrosion properties, and the spacing of the anchor bolts in the weak water erosion area is greater than that in the strong water erosion area, and laying a geogrid based on the anchor bolts.

[0049] The support strategy for the non-water erosion area includes: determining the installation depth according to the rock formation conditions in the non-water erosion area, and installing the anchor bolts into the roadway roof.

[0050] Specifically, according to the detection and analysis results, use mathematical models to simulate and analyze the physical parameters of the roadway roof in the strong water erosion area, weak water erosion area, and non-water erosion area respectively. For example, adopt numerical simulation methods such as the finite element method and the discrete element method, establish a roadway surrounding rock model in combination with FLAC3D software, analyze the compressive strength, tensile strength, cohesion, etc. of the rock formation by simulating the geological conditions of the rock formation and the response when applying support to the surrounding rock, and obtain through experiments the specific range values of the tensile strength and shear performance of the anchor bolts required to achieve the purpose of improving the rock formation anchoring force in different rock formation structures. Thus, formulate corresponding support strategies for different regions.

[0051] The support strategy for the strong water erosion area includes: determining the installation depth according to the rock formation conditions in the strong water erosion area so that the anchor bolts can penetrate into the rock formation with relatively stable rock formation structure; then drill anchor bolt holes at the set positions, after clearing the holes and inspection, inject cement mortar into the anchor bolt holes, insert the anchor bolts into the anchor bolt holes, and inject anchor agents with waterproof and anti-corrosion properties into the anchor bolt holes, so as to tightly combine the anchor bolts with the rock mass, improve the anchoring force of the rock mass, effectively prevent the anchor bolts from being corroded, and improve the service life of the anchor bolts; then lay an anchor net based on the anchor bolts and spray concrete on the metal net, which can effectively prevent the roof rock from falling, further improve the support strength and waterproof performance of the roof, and avoid the deepening of the water erosion degree in the strong water erosion area. Among them, in the strong water erosion area, arrange the anchor bolts in a plum blossom shape. For example, in the area with higher water erosion, the spacing between the anchor bolts can be kept at 0.5M - 0.7M, and the anchor bolts in adjacent two rows are arranged in a staggered manner to ensure the anchoring effect of the anchor bolts and improve the anchoring force of the rock mass.

[0052] The support strategy for the weak water erosion area includes: determining the installation depth according to the rock formation conditions in the weak water erosion area; then drilling bolt holes at the set positions, and after cleaning the holes and inspection, injecting cement mortar into the bolt holes, inserting bolts into the bolt holes, and injecting an anchoring agent with waterproof and anti-corrosion properties to ensure the anchoring effect of the bolts; laying geogrid based on the bolts. The geogrid can enhance the integrity of the rock and effectively inhibit the further development of rock fissures. At the same time, shotcrete can also be sprayed in the weak water erosion area to further prevent the deepening of rock water erosion. Among them, the bolt spacing in the weak water erosion area is greater than that in the strong water erosion area. While ensuring the anchoring effect of the bolts, increasing the bolt spacing in the weak water erosion area can reduce the cost of the support project.

[0053] The support strategy for the non-water erosion area includes: determining the installation depth according to the rock formation conditions in the non-water erosion area, installing bolts into the roadway roof to ensure the anchoring effect of the bolts. In addition, a metal mesh can also be laid in the non-water erosion area, and shotcrete is sprayed on the metal mesh to effectively prevent the roof rock from falling and improve the support structure and anchoring effect.

[0054] S4: Select support tools according to the support strategy. Select a first bolt with a tensile strength higher than that of carbon steel in the strong water erosion area, and spray an anti-corrosion coating on the surface of the first bolt. Select a second bolt with a tensile strength higher than that of carbon steel in the weak water erosion area, and select a third bolt in the non-corrosion area.

[0055] Specifically, since the rock formation structure in the strong water erosion area is damaged and the stability of the rock formation is poor, bolts with a tensile strength higher than that of carbon steel and having corrosion resistance are selected, and an anti-corrosion coating is sprayed on the surface of the first bolt to ensure the stability effect of the bolt and improve the corrosion resistance of the bolt.

[0056] For example, the first bolt in the strong water erosion area is made of 316L stainless steel, which not only has a high tensile strength but also has excellent corrosion resistance. In addition, spray an anti-corrosion coating on the surface of the first bolt, such as an epoxy resin or polyurethane coating, or the first bolt can also be hot-dip galvanized to further enhance the anti-corrosion ability of the bolt and effectively extend the service life of the first bolt. The second bolt in the weak water erosion area also selects a material with a tensile strength higher than that of carbon steel, such as high-strength low-alloy steel, which can ensure the anchoring effect in the weak water erosion area of the bolt and effectively inhibit the deepening of water erosion. The third bolt in the non-water erosion area can choose a standard carbon steel bolt, which has a low cost and can also meet the basic support requirements.

[0057] S5: First complete the support strategy for the weak water erosion area or the non-water erosion area adjacent to the strong water erosion area, and then complete the support strategy for the strong water erosion area to complete the support.

[0058] Specifically, since the rock stratum structures in the weak water erosion area and the non-water erosion area are relatively stable and the construction difficulty is low, the areas adjacent to the strong water erosion area are effectively supported first, which can provide stable boundary conditions for the strong water erosion area, create a safe operation platform for the support of the strong water erosion area, and improve the safety of roadway support construction.

[0059] S6: Real-time monitoring components are arranged at intervals in the strong water erosion area, weak water erosion area, and non-water erosion area to obtain real-time monitoring results. The monitoring results at least include roadway roof displacement, stress change, leakage condition, and bolt stress condition.

[0060] Specifically, according to the specific length and width of the roadway, the monitoring components are arranged at appropriate intervals. For example, a monitoring section is set every 5 meters to 10 meters, and multiple monitoring components are arranged on each section. The monitoring components can cover the top, both side walls, and bottom of the roadway. For the strong water erosion area, the density of the monitoring components can be appropriately increased. For example, a monitoring section is set every 3 meters to 5 meters to ensure that more subtle changes can be captured. In addition, additional monitoring components can also be arranged at key positions such as bolts, geological complexity areas, and fracture development areas. Ensure that the real-time information of the internal support structure of the roadway can be monitored in real time from the outside to ensure the safety of the support structure.

[0061] For example, the detection components can include using equipment such as multi-point displacement meters and total stations to detect roof displacement, using stress sensors to detect roof stress change, using piezometers and humidity sensors to monitor leakage conditions, and using dynamometers to measure bolt stress.

[0062] The monitoring components can establish an automated data system with the outside world, transmit the data of each monitoring point to the central control system in real time, process and interpret the collected data, identify potential safety hazards, and provide early warning information in a timely manner to ensure the safe operation of the support structure.

[0063] In an exemplary embodiment of the present invention, the support strategy for the strong water erosion area further includes setting an auxiliary anode and an external power supply in the strong water erosion area to perform cathodic protection on the first bolt. Specifically, the auxiliary anode can be a graphite rod, a titanium mesh, etc. The auxiliary anode is set around the first bolt at the key position, and a DC power supply is installed. The anode of the power supply is connected to the auxiliary anode, and the cathode is connected to the first bolt, so as to achieve cathodic protection on the first bolt, which can effectively prevent the first bolt from being corroded and improve the service life of the first bolt.

[0064] In an embodiment of the present invention, the metal mesh in the strong water erosion area is woven from steel wires with a corrosion-resistant coating. This is beneficial to improving the waterproof performance of the metal mesh and increasing its service life. In addition, the sprayed concrete in the strong water erosion area can be special concrete with impermeability and corrosion resistance properties. For example, a waterproof agent can be added to the concrete or glass fiber-reinforced concrete can be used. This can further enhance the support strength and waterproof performance of the roof. The thickness of the concrete in the strong water erosion area can be controlled between 150 MM and 250 MM, the thickness of the concrete in the weak water erosion area can be controlled between 100 MM and 150 MM, and the thickness of the concrete in the non-water erosion area can be controlled between 50 MM and 100 MM to ensure that the roof support has good waterproofness and high support strength.

[0065] In an embodiment of the present invention, the length of the first bolt is greater than the length of the second bolt, and the length of the second bolt is greater than the length of the third bolt. Bolts with different lengths are used in areas with different water erosion degrees to ensure that the bolts can penetrate into relatively stable rock formations, thereby guaranteeing the anchoring effect of the bolts. For example, bolts with a length of 3 M are used in the strong water erosion area, bolts with a length of 2.5 M are used in the weak water erosion area, and bolts with a length of 1.5 M are used in the non-corroded area.

[0066] In addition, the distribution density of the first bolts in the strong water erosion area is greater than the distribution density of the second bolts in the weak water erosion area, and the distribution density of the second bolts in the weak water erosion area is greater than the distribution density of the third bolts in the non-water erosion area. This can save costs while ensuring the anchoring effect of the bolts.

[0067] In an exemplary embodiment of the present invention, a transition area metal mesh is laid between the strong water erosion area and the weak water erosion area or between the strong water erosion area and the non-water erosion area transition region, and concrete is sprayed on the transition area metal mesh. This can improve the rock formation stability in the transition region and effectively prevent the deepening of water erosion.

[0068] Furthermore, the laying direction of the transition area metal mesh forms an angle of 30° to 60° with the axis direction of the roadway. The laying direction of the geogrid forms an angle of 30° to 60° with the axis direction of the roadway. For example, the laying direction of the transition area metal mesh and the axis direction of the roadway, as well as the laying direction of the geogrid and the axis direction of the roadway, are both arranged at an angle of 45°, which can effectively inhibit the further development of rock fissures.

[0069] In an embodiment of the present invention, the first bolt includes a main bolt, and at least two expansion shell parts are arranged along the length direction on the main bolt. After the main bolt is installed in the bolt hole, the expansion shell parts expand, which is beneficial to improving the anchoring effect of the bolt.

[0070] In one embodiment of the present invention, the detection and analysis results further include the positions of rock fractures in the roadway roof. Before implementing the support strategy in the strong water erosion area, the rock fractures are filled with cement mortar or anchor agents. This is beneficial to improving the stability of the rock formation, can effectively avoid roof falls, and prevent the formation of water inrush channels.

[0071] The above are only several specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto, and any changes that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A method for zoning support of tunnel roof in water erosion environment, characterized in that: The following steps are involved: S1: Determine the geological conditions of the tunnel roof by geophysical exploration to perform detection and analysis to obtain detection and analysis results, wherein the detection and analysis results at least include geological conditions, rock properties and water erosion degree; S2: dividing the tunnel roof into a strong water erosion area, a weak water erosion area and a non-water erosion area according to the detection and analysis results; S3: According to the detection and analysis results, a mathematical model is used to simulate and analyze the physical parameters of the tunnel roof in the strong water erosion area, the weak water erosion area and the non-water erosion area to determine the support strategy, wherein the support strategy includes the strong water erosion area support strategy, the weak water erosion area support strategy and the non-water erosion area support strategy; The support strategy for the strong water erosion area includes: determining the installation depth according to the rock formation conditions in the strong water erosion area, installing the anchor rods into the tunnel roof, injecting an anchoring agent with waterproof and anti-corrosion properties, arranging the anchor rods in a plum blossom shape, laying an anchor net based on the anchor rods, and spraying concrete on the metal net; The support strategy for the weak water erosion area includes: determining the installation depth according to the rock formation conditions in the weak water erosion area, installing anchor rods into the tunnel roof, injecting an anchoring agent with waterproof and anti-corrosion properties, and the anchor rod spacing in the weak water erosion area is greater than the anchor rod spacing in the strong water erosion area, and laying geogrids based on the anchor rods; The support strategy for the non-water-eroded area includes: determining the installation depth according to the rock formation conditions in the non-water-eroded area, and installing the anchor rods into the top plate of the roadway; S4: selecting a support tool according to the support strategy: selecting a first anchor rod in a strong water erosion area, selecting a second anchor rod in a weak water erosion area, and selecting a third anchor rod in a non-corroded area; S5: first completing the support strategy for the weak water erosion area or the non-water erosion area adjacent to the strong water erosion area, and then completing the support strategy for the strong water erosion area, so as to complete the support; S6: Real-time monitoring components are arranged at intervals in the strong water erosion area, the weak water erosion area and the non-water erosion area to obtain real-time monitoring results, which at least include the displacement of the tunnel roof, stress changes, leakage conditions and anchor force conditions.

2. The method for supporting the tunnel roof in a water erosion environment according to claim 1, characterized in that: The strong water erosion area support strategy also includes: An auxiliary anode and an external power supply are arranged in the strong water erosion area to provide cathodic protection for the first anchor rod.

3. The method for zoning support of tunnel roof in water erosion environment according to claim 1, characterized in that: The metal mesh in the strong water erosion area is made of steel wire with corrosion-resistant coating.

4. The method for supporting the tunnel roof in a water erosion environment according to claim 1, characterized in that: The length of the first anchor rod is greater than that of the second anchor rod, and the length of the second anchor rod is greater than that of the third anchor rod.

5. The method for supporting the tunnel roof in a water erosion environment according to claim 4, characterized in that: The distribution density of the first anchor rods is greater than that of the second anchor rods, and the distribution density of the second anchor rods is greater than that of the third anchor rods.

6. The method for zoning support of tunnel roof in water erosion environment according to claim 1, characterized in that: A transition zone metal mesh is laid between the strong water erosion zone and the weak water erosion zone or between the strong water erosion zone and the non-water erosion zone, and concrete is sprayed on the transition zone metal mesh.

7. The method for supporting the tunnel roof in a water erosion environment according to claim 6, characterized in that: The laying direction of the metal mesh in the transition zone forms an angle of 30° to 60° with the axial direction of the laneway.

8. The method for supporting the tunnel roof in a water erosion environment according to claim 1, characterized in that: The laying direction of the geogrid forms an angle of 30° to 60° with the axial direction of the tunnel.

9. The method for supporting the tunnel roof in a water erosion environment according to claim 1, characterized in that: The first anchor rod comprises a main anchor rod, and at least two expansion shell parts are arranged on the main anchor rod along the length direction.

10. The method for supporting the tunnel roof in a water erosion environment according to claim 1, characterized in that: The detection and analysis results also include the location of rock cracks in the tunnel roof. Before implementing the strong water erosion area support strategy, the rock cracks are filled with cement mortar or anchoring agent.

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