Covering type flexible protection system for dangerous rocks and falling rocks in water conservancy and hydropower engineering

Abstract

The invention discloses a hydraulic and hydro-power engineering dangerous rock falling covering type flexible protection system, and relates to the technical field of slope protection. The water conservancy and hydropower engineering dangerous rock falling covering type flexible protection system comprises flexible anchor rods, boundary supporting ropes, steel bar anchor rods, anchor bearing plates of the steel bar anchor rods and a high-strength noose net with long rhombic meshes. The method further comprises the following steps that the current situation of a side slope is known through on-site survey, the historical and spatial distribution range of dangerous rock falling is investigated, the geological conditions and possible damage forms of dangerous rock are investigated and controlled, geological survey data of a dangerous rock falling area are collected, a geological survey report is written, and dangerous rock caving distribution, danger levels and protective net type suggestions are determined. Proposing protection scheme suggestions, finding out conditions of strong and weak unloading zone development depths, weathering zone depths and the like in the dangerous rock development area, comprehensively determining a protection engineering scheme, and implementing protection engineering; the method has good economical efficiency, buffering performance, environmental protection performance and overall stability, can improve the safety and reliability of the dangerous rock mass, and has obvious superiority.

Description

Technical Field

[0001] The invention relates to the technical field of slope protection, and in particular to a flexible protection system for covering dangerous rocks and falling stones in water conservancy and hydropower engineering. Background Art

[0002] In mountainous areas of my country, especially in the west and southeast, due to complex geological structures, frequent geological disasters, and strong weathering, dangerous rock collapses and rockfalls often occur in mountainous and hilly areas, posing a serious threat to railway, highway, mining, water conservancy and other projects as well as personnel safety. Traditional protection methods such as concrete retaining walls, slope protection, mortar-laid stone, shotcrete slope protection, etc., can provide certain protection, but they have the disadvantages of high cost, great construction difficulty, and great impact on the ecological environment.

[0003] Therefore, it is particularly important to develop a new flexible protection system that can provide effective protection while reducing the impact on the environment. Summary of the invention

[0004] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art and to provide a flexible protection system for covering dangerous rocks and falling stones in water conservancy and hydropower projects, which can solve the problems raised by the above-mentioned background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a flexible covering protection system for dangerous rock and rockfall in water conservancy and hydropower projects, comprising flexible anchor rods, boundary support ropes, steel anchor rods and anchor pads, and high-strength rope nets with rhombus-shaped meshes; the arrangement range of the protection net should extend to the upper edge and the two side edges by not less than 2m respectively; the covering flexible protection system is suitable for slopes ≤75°; the steel anchor rod has a diameter of φ25, with claws at both ends and a length of ≥320mm; the anchor pad has a thickness of ≥10mm; the boundary support rope has a diameter of φ16, and the flexible anchor rod has a diameter of φ20; the covering flexible protection system is suitable for single dangerous rock masses with a volume of ≤1m 3 The diameter of the long rhombus high-strength rope net steel wire is 2mm, and the mesh size is 50mm;

[0006] The axial tensile force value of the steel anchor is 80KN, the length is 4.5m, and the spacing is 3m; the axial tensile bearing capacity of the anchor rod body can be calculated as follows:

[0007] R t ≥γ0N d

[0008] Where: R—design value of axial tensile bearing capacity of anchor rod body N;

[0009] Nd—design value of anchor rod axial tension N;

[0010] γ0—Anchor bearing capacity reserve coefficient, which is 1.35, 1.25, and 1.15 for protection projects with safety levels of Ⅰ, Ⅱ, and Ⅲ respectively;

[0011] The bearing capacity of the flexible anchor rod 1, the boundary support rope 2, the anchor pad 3 and the high-strength rope net 4 with rhombus-shaped meshes can be calculated as follows:

[0012] KP≤R

[0013] Where: P—load standard value kN;

[0014] R—design value of bearing capacity in kN.

[0015] K—load partial coefficient, which can be based on the safety level of the protection project. For protection projects with safety levels Ⅰ, Ⅱ, and Ⅲ, the K value should not be less than 2.0, 1.5, and 1.0 respectively.

[0016] The following steps are also included:

[0017] S1. On-site investigation to understand the current situation of the slope

[0018] Objective: To fully understand the current status of the slope, dangerous rock mass and potential risks of rockfall through on-site investigation;

[0019] Specific practices: Conduct a panoramic inspection of the slope by walking or using drones to record and photograph key locations; identify and mark potential source areas of dangerous rockfall, existing rockfall traces, and areas prone to collapse;

[0020] Pay attention to rock cracks, signs of landslides and vegetation coverage, and record obvious weathering, erosion and crack development; make preliminary comparisons with local climate, seismic activity, rainfall and other environmental conditions to assess potential influencing factors.

[0021] S2. Investigate the history and spatial distribution of dangerous rockfalls

[0022] Objective: To understand the historical occurrence and potential distribution of dangerous rockfalls through historical data and field investigations;

[0023] Specific practices: Collect and analyze historical records of rockfall and collapse, including the time, scale, location and related meteorological and geological conditions of rockfall; use remote sensing technologies such as satellite images and Li DAR to conduct macroscopic scans of slopes to identify dangerous rocks and rockfall areas; through local investigations, calibrate and record the rockfalls that have occurred to understand the environmental conditions and rock types in which they occurred.

[0024] S3. Investigate the geological conditions and possible forms of damage to control dangerous rocks

[0025] Objective: To understand in detail the causes, controlling factors and possible forms of damage of dangerous rocks in order to develop protection plans;

[0026] Specific practices: Conduct geological exploration of rocks and soil layers, use drilling sampling and physical experiments to conduct quantitative analysis of rock strength, hardness, weathering degree, etc.; analyze the distribution and depth of weathering zones and unloading zones on the slope to determine which parts may cause instability of the rock mass; investigate geological phenomena such as cracks, faults, and landslides, and evaluate their impact on the collapse of dangerous rocks; identify possible forms of damage such as rock collapse, landslides, mudslides, etc., and correspond to protective measures.

[0027] S4. Collect geological survey data on dangerous rockfall areas

[0028] Objective: To provide data support for protection system design through on-site exploration and collection of relevant information;

[0029] Refinement steps:

[0030] Specific practices: Collect regional geological survey reports, including rock layer distribution, soil layer conditions, groundwater level, fracture development, etc.; if the existing geological survey data is not detailed enough or there are doubts, arrange for exploration equipment such as drilling, shallow ground radar, laser scanning, etc. to conduct supplementary exploration; obtain historical engineering data related to protection design, including the history of rockfall protection in adjacent areas and effect evaluation.

[0031] S5. Prepare geological survey report

[0032] Objective: To organize the investigation and analysis results into a complete geological survey report to provide a basis for the design of subsequent protection plans.

[0033] Specific practices: When writing the report, describe in detail the spatial distribution, formation mechanism, potential hazards and risk analysis of dangerous rockfalls; analyze the rock stability, crack development and other possible damage mechanisms in the area, and provide corresponding hazard and risk assessments; combine historical events, geological exploration data and other analyses to assess the collapse potential of dangerous rocks and conduct stability evaluations; provide recommended protection plans, including necessary protection types, protection levels, safety requirements, etc.

[0034] S6. Determine the distribution of dangerous rock collapse, hazard level, and protection net type recommendations

[0035] The type of protection net is determined based on geological assessment and rockfall impact energy, and consideration should also be given to how to select and configure various protection system components such as flexible anchors, steel anchors, boundary support ropes and high-strength cable nets.

[0036] Flexible anchor rod:

[0037] Function: Flexible anchor rods are mainly used to anchor the rock mass to provide long-term stability and prevent rock sliding or collapse; the arrangement of anchor rods can effectively disperse the stress of the rock mass and increase the tensile and impact resistance of the protection net;

[0038] Design requirements: Determine the length, diameter, density and spacing of anchor rods based on the stability analysis of the slope. For areas with greater collapse risk, the arrangement of anchor rods should be more dense to improve the protection effect;

[0039] Construction points: The driving depth of the anchor rod should be determined according to the strength and weathering degree of the rock mass to ensure that the anchoring force of the anchor rod meets the design requirements. Special treatment should be taken at the end of the anchor rod to avoid anchor failure caused by environmental factors such as humidity, acidity and alkalinity;

[0040] Boundary support rope:

[0041] Function: Boundary support ropes are mainly used to improve the stability of the protection net, especially on the upper part and both sides of the slope. They enhance the overall tensile strength of the net through evenly distributed force to prevent the protection net from breaking or shifting when a large-scale rockfall impacts.

[0042] Design requirements: The material of the boundary support rope should be steel cable or polymer rope with strong corrosion resistance and good ductility. The spacing of the support rope should be designed according to the size and protection requirements of the protection net to ensure that the net is stable and can effectively withstand large-scale rockfall;

[0043] Construction points: The installation of the support rope should start from the top of the slope, ensure that it is firmly connected, and set up necessary tension devices to control the tightness of the rope. The fixed end of the support rope should be installed on a solid anchor point;

[0044] Steel bar anchor and anchor plate:

[0045] Function: Steel anchor rods and anchor pads are mainly used to strengthen the anchoring system of the ground or slope, and to improve the stability and load resistance of the protection net by increasing the anchoring area and dispersing the anchoring force;

[0046] Design requirements: The diameter and length of the steel anchor rod should be designed according to the stability of the rock mass and the strength requirements of the protective net. The size of the anchor plate should ensure that the anchoring force can be evenly distributed to avoid anchor failure due to local concentrated stress;

[0047] Construction points: The installation of steel anchor rods requires strict control of verticality and hole depth to ensure the anchoring effect. The installation of anchor pads must ensure close contact with the rock mass to avoid loosening or sliding;

[0048] High-strength noose net with rhombus-shaped mesh:

[0049] Function: The high-strength rope net plays a direct role in preventing dangerous rocks and falling rocks. Its special diamond mesh structure can provide greater tensile strength and effectively disperse the impact of falling rocks;

[0050] Design requirements: According to actual needs, select the appropriate specifications of the noose net. The mesh size should be designed according to the block size of the protection target, the kinetic energy of the falling rocks and other parameters to ensure that the net can effectively bear the impact load and prevent the falling rocks from falling off;

[0051] Construction points: The noose net needs to be accurately installed on the anchoring system, and the tension of the net body should be reasonably distributed to avoid local stress concentration. High-strength connectors are required at the connection points between the net body and the anchoring system to ensure its stability and durability.

[0052] S7. Propose protection plan suggestions

[0053] Comprehensively consider factors such as rock mass stability and hazard level, and refine the configuration of the protection net, including the combination of different components and the construction sequence;

[0054] Combination of flexible anchor rods and steel anchor rods: In the protection scheme, it is usually recommended to use flexible anchor rods in combination with steel anchor rods to improve the overall stability of the slope. Flexible anchor rods are usually used for large-scale mesh support, while steel anchor rods can be used to strengthen key parts, especially where there is a clear risk of landslides or where rock weathering is severe;

[0055] Configuration of boundary support ropes: According to the shape of the slope and the movement trajectory of the falling rocks, the arrangement of boundary support ropes should ensure uniform tension of the entire protection system. Usually, the setting of boundary support ropes should include upper and lower support ropes to ensure the stability of the protection net in the vertical and horizontal directions;

[0056] Net tension and winding requirements: The protective net should maintain appropriate tension. Too loose or too tight will affect the protection effect. The appropriate tension of the net can be ensured by adjusting the tension of the anchor rod or using a tension device. In addition, the winding of the net needs to ensure that there are no loose parts to avoid the net from sliding or falling off during later use.

[0057] S8. Find out the depth of strong and weak unloading zones and weathering zones in dangerous rock development areas.

[0058] For strong unloading zones, it is recommended to use denser anchor rods and stronger meshes, such as high-strength cable nets, to enhance the overall impact resistance of the protection system; for areas with deeper weathering zones, it is necessary to consider using longer anchor rods and combining them with steel anchor rods to reinforce the contact points of the mesh to prevent local collapse of the rock mass; in the junction area of ​​the strong unloading zone and the weathering zone, a more complex protection system can be considered, such as a protection design combined with boundary support ropes to ensure the stability of the mesh.

[0059] S9. Comprehensively determine the protection project plan and implement the protection project

[0060] During the implementation phase of the protection project, especially when installing the protection net components, it is necessary to ensure the coordination and installation order of all components to improve the overall protection effect; Installation order: The steel anchor rods and their anchor pads should be installed first, followed by the flexible anchor rods and support ropes, and finally the net body installation and tensioning work; Quality control: The installation quality of each link needs to be strictly monitored to ensure that the anchoring force and net body tension meet the design requirements. Especially when installing high-strength cable nets, ensure that the net body is not loose or damaged.

[0061] Compared with the prior art, the present invention has the following beneficial effects:

[0062] Flexible covering: Utilize the flexibility and coverage of the flexible net to achieve comprehensive protection of the slope and effectively suppress the occurrence of dangerous rock collapse and rockfall.

[0063] Environmentally friendly and beautiful: After the system is installed, it will not affect the growth of the original vegetation on the slope and is easy to blend with the surrounding environment, achieving the effect of both protection and beautification.

[0064] Economical: Compared with traditional protection methods, this system has a short construction period, low cost and easy maintenance.

[0065] Adaptability: Suitable for slope protection of various slopes, rock types and climatic conditions.

[0066] In summary, compared with the prior art, the flexible protection system for covering dangerous rocks and falling rocks in water conservancy and hydropower projects of the present invention has better economy, buffering, environmental protection and overall stability, can improve the safety and reliability of dangerous rock bodies, and has obvious advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] The present invention is further described below in conjunction with the accompanying drawings and embodiments:

[0068] Figure 1 This is a schematic diagram of the plane layout of the patent of this invention;

[0069] In the figure: 1-flexible anchor rod, 2-boundary support rope, 3-reinforcement anchor rod and anchor pad, 4-high-strength cable net with rhombus-shaped mesh. DETAILED DESCRIPTION

[0070] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0071] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0072] In the description of the present invention, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0073] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0074] See also Figure 1 The present invention provides a technical solution: a flexible covering protection system for dangerous rock and rockfall in water conservancy and hydropower projects, comprising a flexible anchor rod 1, a boundary support rope 2, a steel anchor rod and its anchor pad 3, and a high-strength rope net 4 with rhombus-shaped meshes; the arrangement range of the protection net should extend to the upper edge and the two side edges by no less than 2m respectively; the covering flexible protection system is suitable for a slope of ≤75°; the steel anchor rod has a diameter of φ25, with claws at both ends and a length of ≥320mm; the anchor pad has a thickness of ≥10mm; the boundary support rope has a diameter of φ16, and the flexible anchor rod has a diameter of φ20; the covering flexible protection system is suitable for a single dangerous rock mass with a volume of ≤1m 3 The diameter of the long rhombus high-strength rope net steel wire is 2mm, and the mesh size is 50mm;

[0075] The axial tensile force value of the steel anchor is 80KN, the length is 4.5m, and the spacing is 3m; the axial tensile bearing capacity of the anchor rod body can be calculated as follows:

[0076] R t ≥γ0N d

[0077] Where: R—design value of axial tensile bearing capacity of anchor rod body N;

[0078] Nd—design value of anchor rod axial tension N;

[0079] γ0—Anchor bearing capacity reserve coefficient, which is 1.35, 1.25, and 1.15 for protection projects with safety levels of Ⅰ, Ⅱ, and Ⅲ respectively;

[0080] The bearing capacity of the flexible anchor rod 1, the boundary support rope 2, the anchor pad 3 and the high-strength rope net 4 with rhombus-shaped meshes can be calculated as follows:

[0081] KP≤R

[0082] Where: P—load standard value kN;

[0083] R—design value of bearing capacity in kN.

[0084] K—load partial coefficient, which can be based on the safety level of the protection project. For protection projects with safety levels Ⅰ, Ⅱ, and Ⅲ, the K value should not be less than 2.0, 1.5, and 1.0 respectively.

[0085] The following steps are also included:

[0086] S1. On-site investigation to understand the current situation of the slope

[0087] Conduct a panoramic inspection of the slope by walking or using drones to record and photograph key locations; identify and mark potential source areas of dangerous rockfall, existing traces of rockfall, and areas prone to collapse; pay attention to rock cracks, signs of landslides, and vegetation coverage, and record obvious weathering, erosion, and crack development; conduct a preliminary comparison with local climate, seismic activity, rainfall and other environmental conditions to evaluate potential influencing factors.

[0088] S2. Investigate the history and spatial distribution of dangerous rockfalls

[0089] Collect and analyze historical records of rockfall and collapse events, including the time, scale, location, and related meteorological and geological conditions of rockfalls; use remote sensing technologies such as satellite imagery and Li DAR to conduct macroscopic scans of slopes to identify dangerous rocks and rockfall areas; through local investigations, calibrate and record rockfalls that have occurred to understand the environmental conditions and rock types in which they occurred.

[0090] S3. Investigate the geological conditions and possible forms of damage to control dangerous rocks

[0091] Conduct geological exploration of rocks and soil layers, and use drilling sampling and physical experiments to conduct quantitative analysis of rock strength, hardness, weathering degree, etc.; analyze the distribution and depth of weathering zones and unloading zones on the slope to determine which parts may cause instability in the rock mass; investigate geological phenomena such as cracks, faults, and landslides, and evaluate their impact on the collapse of dangerous rocks; identify possible forms of damage such as rock collapse, landslides, mudslides, etc., and correspond to protective measures.

[0092] S4. Collect geological survey data on dangerous rockfall areas

[0093] Collect regional geological survey reports, including rock layer distribution, soil layer conditions, groundwater level, fissure development, etc.; if the existing geological survey data is not detailed enough or there are doubts, arrange for additional exploration with exploration equipment such as drilling, shallow-layer radar, laser scanning, etc.; obtain historical engineering data related to protection design, including the history of rockfall protection in adjacent areas and effect evaluation.

[0094] S5. Prepare geological survey report

[0095] When writing the report, describe in detail the spatial distribution, formation mechanism, potential hazards and risk analysis of dangerous rock falls; analyze the rock stability, crack development and other possible damage mechanisms in the area, and give corresponding hazard and risk assessments; combine historical events, geological exploration data and other analyses to assess the collapse potential of dangerous rocks and conduct stability evaluations; provide recommended protection plans, including necessary protection types, protection levels, safety requirements, etc.

[0096] S6. Determine the distribution of dangerous rock collapse, hazard level, and protection net type recommendations

[0097] The type of protection net is determined based on geological assessment and rockfall impact energy, and consideration should also be given to how to select and configure various protection system components such as flexible anchors, steel anchors, boundary support ropes and high-strength cable nets.

[0098] Flexible anchor rod 1: Flexible anchor rod is mainly used to provide long-term stability by anchoring rock mass to prevent rock sliding or collapse; the arrangement of anchor rod can effectively disperse the stress of rock mass and increase the tensile strength and impact resistance of protection net;

[0099] According to the stability analysis of the slope, determine the length, diameter, density and spacing of the anchor rods. For areas with greater collapse risk, the anchor rods should be arranged more densely to improve the protection effect;

[0100] Construction points: The driving depth of the anchor rod should be determined according to the strength and weathering degree of the rock mass to ensure that the anchoring force of the anchor rod meets the design requirements. Special treatment should be taken at the end of the anchor rod to avoid anchor failure caused by environmental factors such as humidity, acidity and alkalinity;

[0101] Boundary Support Rope 2:

[0102] Boundary support ropes are mainly used to improve the stability of the protection net, especially on the upper part and both sides of the slope. They enhance the overall tensile strength of the net through evenly distributed force to prevent the protection net from breaking or shifting when a large-scale rockfall impacts.

[0103] The material of the boundary support rope should be steel cable or polymer rope with strong corrosion resistance and good ductility. The spacing of the support rope should be designed according to the size and protection requirements of the protection net to ensure that the net is stable and can effectively withstand large-scale rockfall;

[0104] The installation of the support rope should start from the top of the slope, ensure that it is firmly connected, and set up necessary tension devices to control the tightness of the rope. The fixed end of the support rope should be installed on a solid anchor point;

[0105] Steel bar anchor and anchor plate 3:

[0106] Steel bar anchor rods and their anchor pads are mainly used to strengthen the anchoring system of the ground or slope, and to improve the stability and load resistance of the protection net by increasing the anchoring area and dispersing the anchoring force;

[0107] The diameter and length of the steel anchor rod should be designed according to the stability of the rock mass and the strength requirements of the protection net. The size of the anchor plate should ensure that the anchoring force can be evenly distributed to avoid anchor failure due to local concentrated stress;

[0108] The installation of steel anchor rods requires strict control of verticality and hole depth to ensure anchoring effect. The installation of anchor pads must ensure close contact with the rock mass to avoid loosening or sliding;

[0109] High-strength noose net with rhombus-shaped mesh 4:

[0110] The high-strength rope net plays a direct role in preventing dangerous rocks and falling rocks. Its special diamond mesh structure can provide greater tensile strength and effectively disperse the impact of falling rocks.

[0111] According to actual needs, select the appropriate specifications of the noose net. The mesh size should be designed according to the block size of the protection target, the kinetic energy of the falling rocks and other parameters to ensure that the net can effectively bear the impact load and prevent the falling rocks from falling off;

[0112] The noose net needs to be accurately installed on the anchoring system, and the tension of the net should be reasonably distributed to avoid local stress concentration. High-strength connectors are required at the connection points between the net and the anchoring system to ensure its stability and durability.

[0113] S7. Propose protection plan suggestions

[0114] Comprehensively consider factors such as rock mass stability and hazard level, and refine the configuration of the protection net, including the combination of different components and the construction sequence;

[0115] Combination of flexible anchor rods and steel anchor rods: In the protection scheme, it is usually recommended to use flexible anchor rods in combination with steel anchor rods to improve the overall stability of the slope. Flexible anchor rods are usually used for large-scale mesh support, while steel anchor rods can be used to strengthen key parts, especially where there is a clear risk of landslides or where rock weathering is severe;

[0116] Configuration of boundary support ropes: According to the shape of the slope and the movement trajectory of the falling rocks, the arrangement of boundary support ropes should ensure uniform tension of the entire protection system. Usually, the setting of boundary support ropes should include upper and lower support ropes to ensure the stability of the protection net in the vertical and horizontal directions;

[0117] Net tension and winding requirements: The protective net should maintain appropriate tension. Too loose or too tight will affect the protection effect. The appropriate tension of the net can be ensured by adjusting the tension of the anchor rod or using a tension device. In addition, the winding of the net needs to ensure that there are no loose parts to avoid the net from sliding or falling off during later use.

[0118] S8. Find out the depth of strong and weak unloading zones and weathering zones in dangerous rock development areas.

[0119] For strong unloading zones, it is recommended to use denser anchor rods and stronger meshes, such as high-strength cable nets, to enhance the overall impact resistance of the protection system; for areas with deeper weathering zones, it is necessary to consider using longer anchor rods and combining them with steel anchor rods to reinforce the contact points of the mesh to prevent local collapse of the rock mass; in the junction area of ​​the strong unloading zone and the weathering zone, a more complex protection system can be considered, such as a protection design combined with boundary support ropes to ensure the stability of the mesh.

[0120] S9. Comprehensively determine the protection project plan and implement the protection project

[0121] During the implementation phase of the protection project, especially when installing the protection net components, it is necessary to ensure the coordination and installation order of all components to improve the overall protection effect; Installation order: The steel anchor rods and their anchor pads should be installed first, followed by the flexible anchor rods and support ropes, and finally the net body installation and tensioning work; Quality control: The installation quality of each link needs to be strictly monitored to ensure that the anchoring force and net body tension meet the design requirements. Especially when installing high-strength cable nets, ensure that the net body is not loose or damaged.

[0122] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. A flexible protection system for dangerous rock falls in water conservancy and hydropower projects, characterized in that: include: Flexible anchor rods (1), boundary support ropes (2), steel anchor rods and anchor pads (3), and a high-strength cable net with rhombus-shaped meshes (4); The specific steps include: S1. On-site investigation to understand the current situation of the slope Objective: To fully understand the current status of the slope, dangerous rock mass and potential risks of rockfall through on-site investigation; Specific practices: Conduct a panoramic inspection of the slope by walking or using drones to record and photograph key locations; identify and mark potential source areas of dangerous rockfall, existing rockfall traces, and areas prone to collapse; Pay attention to rock cracks, signs of landslides and vegetation coverage, and record obvious weathering, erosion and crack development; make preliminary comparisons with local climate, seismic activity, rainfall and other environmental conditions to assess potential influencing factors. S2. Investigate the history and spatial distribution of dangerous rockfalls Objective: To understand the historical occurrence and potential distribution of dangerous rockfalls through historical data and field investigations; Specific practices: Collect and analyze historical records of rockfall and collapse, including the time, scale, location and related meteorological and geological conditions of rockfall; use remote sensing technology (such as satellite imagery, LiDAR, etc.) to conduct macroscopic scans of slopes to identify dangerous rocks and rockfall areas; through local investigations, calibrate and record the rockfalls that have occurred to understand the environmental conditions and rock types in which they occurred. S3. Investigate the geological conditions and possible forms of damage to control dangerous rocks Objective: To understand in detail the causes, controlling factors and possible forms of damage of dangerous rocks in order to develop protection plans; Specific practices: Conduct geological exploration of rocks and soil layers, use drilling sampling and physical experiments to conduct quantitative analysis of rock strength, hardness, weathering degree, etc.; analyze the distribution and depth of weathering zones and unloading zones on the slope to determine which parts may cause instability of the rock mass; investigate geological phenomena such as cracks, faults, and landslides, and evaluate their impact on the collapse of dangerous rocks; identify possible forms of damage (such as rock collapse, landslides, mudslides, etc.) and correspond to protective measures. S4. Collect geological survey data on dangerous rockfall areas Objective: To provide data support for protection system design through on-site exploration and collection of relevant information; Specific practices: Collect regional geological survey reports, including rock layer distribution, soil layer conditions, groundwater level, fracture development, etc.; if the existing geological survey data is not detailed enough or there are doubts, arrange for exploration equipment (such as drilling, shallow ground radar, laser scanning, etc.) to conduct supplementary exploration; obtain historical engineering data related to protection design, including the history of rockfall protection in adjacent areas and effect evaluation. S5. Prepare geological survey report Objective: To organize the investigation and analysis results into a complete geological survey report to provide a basis for the design of subsequent protection plans. Specific practices: When writing the report, describe in detail the spatial distribution, formation mechanism, potential hazards and risk analysis of dangerous rockfalls; analyze the rock stability, crack development and other possible damage mechanisms in the area, and provide corresponding hazard and risk assessments; combine historical events, geological exploration data and other analyses to assess the collapse potential of dangerous rocks and conduct stability evaluations; provide recommended protection plans, including necessary protection types, protection levels, safety requirements, etc. S6. Determine the distribution of dangerous rock collapse, hazard level, and protection net type recommendations The type of protection net should be determined based on geological assessment and rockfall impact energy, and consideration should also be given to how to select and configure the various protection system components (such as flexible anchors, steel anchors, boundary support ropes and high-strength cable nets). Flexible anchor(1): Function: Flexible anchor rods are mainly used to anchor the rock mass to provide long-term stability and prevent rock sliding or collapse; the arrangement of anchor rods can effectively disperse the stress of the rock mass and increase the tensile and impact resistance of the protection net; Design requirements: Determine the length, diameter, density and spacing of anchor rods based on the stability analysis of the slope. For areas with greater collapse risk, the arrangement of anchor rods should be more dense to improve the protection effect; Construction points: The driving depth of the anchor rod should be determined according to the strength and weathering degree of the rock mass to ensure that the anchoring force of the anchor rod meets the design requirements. Special treatment should be taken at the end of the anchor rod to avoid anchor failure caused by environmental factors (such as humidity, acidity and alkalinity, etc.); Boundary support rope (2): Function: Boundary support ropes are mainly used to improve the stability of the protection net, especially on the upper part and both sides of the slope. They enhance the overall tensile strength of the net through evenly distributed force to prevent the protection net from breaking or shifting when a large-scale rockfall impacts. Design requirements: The material of the boundary support rope should be steel cable or polymer rope with strong corrosion resistance and good ductility. The spacing of the support rope should be designed according to the size and protection requirements of the protection net to ensure that the net is stable and can effectively withstand large-scale rockfall; Construction points: The installation of the support rope should start from the top of the slope, ensure that it is firmly connected, and set up necessary tension devices to control the tightness of the rope. The fixed end of the support rope should be installed on a solid anchor point; Steel bar anchor and anchor pad (3): Function: Steel anchor rods and anchor pads are mainly used to strengthen the anchoring system of the ground or slope, and to improve the stability and load resistance of the protection net by increasing the anchoring area and dispersing the anchoring force; Design requirements: The diameter and length of the steel anchor rod should be designed according to the stability of the rock mass and the strength requirements of the protective net. The size of the anchor plate should ensure that the anchoring force can be evenly distributed to avoid anchor failure due to local concentrated stress; Construction points: The installation of steel anchor rods requires strict control of verticality and hole depth to ensure the anchoring effect. The installation of anchor pads must ensure close contact with the rock mass to avoid loosening or sliding; High-strength rope net with rhombus-shaped mesh (4): Function: The high-strength rope net plays a direct role in preventing dangerous rocks and falling rocks. Its special diamond mesh structure can provide greater tensile strength and effectively disperse the impact of falling rocks; Design requirements: According to actual needs, select the appropriate specifications of the noose net. The mesh size should be designed according to the block size of the protection target, the kinetic energy of the falling rocks and other parameters to ensure that the net can effectively bear the impact load and prevent the falling rocks from falling off; Construction points: The noose net needs to be accurately installed on the anchoring system, and the tension of the net body should be reasonably distributed to avoid local stress concentration. High-strength connectors are required at the connection points between the net body and the anchoring system to ensure its stability and durability. S7. Propose protection plan suggestions Comprehensively consider factors such as rock mass stability and hazard level, and refine the configuration of the protection net, including the combination of different components and the construction sequence; Combination of flexible anchor rods and steel anchor rods: In the protection scheme, it is usually recommended to use flexible anchor rods in combination with steel anchor rods to improve the overall stability of the slope. Flexible anchor rods are usually used for large-scale mesh support, while steel anchor rods can be used to strengthen key parts, especially where there is a clear risk of landslides or where rock weathering is severe; Configuration of boundary support ropes: According to the shape of the slope and the movement trajectory of the falling rocks, the arrangement of boundary support ropes should ensure uniform tension of the entire protection system. Usually, the setting of boundary support ropes should include upper and lower support ropes to ensure the stability of the protection net in the vertical and horizontal directions; Net tension and winding requirements: The protective net should maintain appropriate tension. Too loose or too tight will affect the protection effect. The appropriate tension of the net can be ensured by adjusting the tension of the anchor rod or using a tension device. In addition, the winding of the net needs to ensure that there are no loose parts to avoid the net from sliding or falling off during later use. S8. Find out the depth of strong and weak unloading zones and weathering zones in dangerous rock development areas. For the strong unloading zone, it is recommended to use denser anchor rods and stronger mesh (such as high-strength cable net) to enhance the overall impact resistance of the protection system; for areas with deeper weathering zones, it is necessary to consider using longer anchor rods and combine them with steel anchor rods to reinforce the contact points of the mesh to prevent local collapse of the rock mass; in the junction area of ​​the strong unloading zone and the weathering zone, a more complex protection system can be considered, such as a protection design combined with boundary support ropes to ensure the stability of the mesh. S9. Comprehensively determine the protection project plan and implement the protection project During the implementation phase of the protection project, especially when installing the protection net components, it is necessary to ensure the coordination and installation sequence of all components to improve the overall protection effect; Installation sequence: The steel anchor rods and their anchor pads should be installed first, followed by the flexible anchor rods and support ropes, and finally the net body installation and tensioning work; Quality control: The installation quality of each link needs to be strictly monitored to ensure that the anchoring force and net body tension meet the design requirements. Especially when installing high-strength cable nets, ensure that the net body is not loose or damaged.

2. The flexible protection system for dangerous rock falls in water conservancy and hydropower projects according to claim 1 is characterized by: The protection net layout range should extend no less than 2m to the upper edge and both side edges respectively.

3. A flexible protection system for dangerous rock falls in water conservancy and hydropower projects according to claim 2, characterized in that: The covering flexible protection system is suitable for slopes ≤ 75°.

4. The flexible protection system for dangerous rock falls in water conservancy and hydropower projects according to claim 3 is characterized by: The steel bar anchor rod has a diameter of φ25, claws at both ends and a length of ≥320mm.

5. The flexible protection system for dangerous rock falls in water conservancy and hydropower projects according to claim 4 is characterized by: The thickness of the anchor plate is ≥10mm.

6. The flexible protection system for dangerous rock falls in water conservancy and hydropower projects according to claim 5 is characterized by: The diameter of the boundary support rope is φ16, and the diameter of the flexible anchor rod is φ20.

7. The flexible protection system for dangerous rock falls in water conservancy and hydropower projects according to claim 6 is characterized by: The axial tensile force value of the steel anchor is 80KN, the length is 4.5m, and the spacing is 3m; the axial tensile bearing capacity of the anchor rod body can be calculated as follows: R t ≥γ0N d Where: R—design value of axial tensile bearing capacity of anchor rod body (N); Nd—design value of anchor rod axial tension (N); γ0—Anchor bearing capacity reserve coefficient, which is 1.35, 1.25, and 1.15 for protection projects with safety levels Ⅰ, Ⅱ, and Ⅲ respectively.

8. The flexible protection system for dangerous rock falls in water conservancy and hydropower projects according to claim 7 is characterized by: The covering flexible protection system is suitable for single dangerous rock mass with a volume of ≤1m 3 .

9. The flexible protection system for dangerous rock falls in water conservancy and hydropower projects according to claim 8, characterized in that: The diameter of the rhombus-shaped high-strength rope net steel wire is 2 mm, and the mesh size is 50 mm.

10. A flexible protection system for dangerous rock falls in water conservancy and hydropower projects according to claim 9, characterized in that: The bearing capacity of the flexible anchor rod (1), the boundary support rope (2), the anchor pad (3) and the high-strength rope net (4) with rhombus-shaped meshes can be calculated as follows: KP≤R Where: P—load standard value (kN); R—design value of bearing capacity (kN). K—load partial coefficient, which can be based on the safety level of the protection project. For protection projects with safety levels Ⅰ, Ⅱ, and Ⅲ, the K value should not be less than 2.0, 1.5, and 1.0 respectively.

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