Anti-corrosion reinforcing method for interchange roadway of loose coal pillar body
By combining I-shaped steel beams, steel sheds, spray support and waterproof drainage systems, the problem of easy corrosion of loose coal column overpass tunnels is solved, long-term and stable coal column protection and rust risk prediction are achieved, and the overall stability of coal columns is ensured.
Patent Information
- Application Number
- CN202510394403.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-31
- Publication Date
- 2025-07-18
AI Technical Summary
In the overpass tunnel support of loose coal columns, the problem of short reinforcement effect and easy damage to the overall structure of the protective coal column due to corrosion and permeation of water accumulation in the upper tunnel.
I-shaped steel beams, I-shaped steel sheds and spray support are combined with waterproof materials and drainage systems to protect the coal columns from both sides of the upper and lower tunnels, and the degree of corrosion is predicted through infrared thermal imaging and electromagnetic scanners, and combined with BIM and ANSYS to simulate the rust diffusion trend to predict future corrosion risks.
The double-sided protection of coal columns is achieved, effectively preventing the inflow of wastewater on the working face, improving the stability of coal columns, and timely predicting the degree of rust, extending the support effect.
Smart Images
Figure CN120331807A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of coal seam overpass reinforcement, and specifically relates to an anti-corrosion reinforcement method for overpass roadways in loose coal pillars. Background Art
[0002] Currently, the known overpass support reinforcement measures in the industry mostly adopt reinforcement measures such as driving I-beams in the lower roadway, using I-beam sheds, and shotcreting.
[0003] 1. Using I-beam support: In the lower part of the excavated roadway, that is, within the range where the excavated roadway is affected by the upper roadway, drive I-beams perpendicular to the roadway trend direction. Each I-beam uses three φ22mm high-strength anchor cables to ensure that the anchor cables are anchored in the protective coal pillar to reinforce the protective coal pillar.
[0004] 2. Using I-beam shed and shotcrete support: Adopt 11# I-beams, with the shed beam length of 5000 mm and the shed spacing of 500 mm. Use magnesite backplates with a specification of 1000×100×50 mm to compact the top, and then spray the top flat with shotcrete to prevent weathering and strengthen the support and reinforcement of the arch.
[0005] For the above-known support reinforcement technologies, the advantages are that they can effectively protect the lower roadway from deformation, the support effect is good in a short time, the support is simple, and the investment cost is low. The disadvantages are that the reinforcement effect lasts for a short time. Due to the small and loose reserved protective coal pillar, affected by the corrosion and infiltration of the upper roadway water accumulation, the integrity structure of the protective coal pillar is damaged, resulting in the failure of the bolt and cable support. Summary of the Invention
[0006] Aiming at the above problems existing in the prior art, the purpose of the present invention is to provide an anti-corrosion reinforcement method for overpass roadways in loose coal pillars, which can provide double-sided protection for the coal pillar from the upper and lower roadways. At the same time, the upper part uses methods such as pouring and interception to effectively prevent the waste water from the working face from flowing into the coal pillar, effectively ensuring the stability of the protective coal pillar.
[0007] To solve the above problems, the technical solutions adopted by the present invention are as follows: An anti-corrosion reinforcement method for overpass roadways in loose coal pillars, the method includes the following steps: (1) Determine the range of the overpass roadway to be reinforced, and use I-beams, I-beam sheds and shotcrete to support the overpass roadway. Among them, the length of the support anchor cable of the I-beam near the lower part of the overpass roadway is greater than the thickness of the protective coal pillar, and I-beams are added to the bottom plate of the upper part of the overpass roadway so that the anchor cables on both sides are tightened together; After tensioning the I-beam steel above the interchange roadway, lay waterproof materials in the interchange area and pour them. The concrete materials are selected as composite Portland cement, river sand, and cobblestones with a particle size of 20 - 40 mm. The weight mix ratio is respectively composite Portland cement : river sand : cobblestones = 0.8 - 2 : 2.15 - 3.04 : 4.0 - 5.2, the water-cement ratio is 0.60 - 0.63, and the pouring thickness is 480 - 520 mm; (3) Install a drain pipe in the water channel within the upper range of the interchange roadway and connect it to the outside of the interchange roadway.
[0008] Furthermore, a plurality of infrared thermal imaging steel bar scanners are provided in the interchange roadway. The reinforcement range of the interchange roadway is demarcated into a shallow reinforcement area and a deep reinforcement area. For the shallow reinforcement area, an electromagnetic induction type steel bar scanner is used. For the deep reinforcement area, a ground penetrating radar steel bar scanner is used. At the same time, a multi-frequency electromagnetic scanner is used to distinguish the signal differences of steel bars with different corrosion degrees.
[0009] Furthermore, the shallow reinforcement area and the deep reinforcement area are divided in a grid manner. The positions, depths, and signal intensities of the steel bars are respectively recorded regularly by the two types of steel bar scanners. Through the signals emitted by the multi-frequency electromagnetic scanner, potential corrosion points are located for signal abnormal areas; The process of predicting the corrosion diffusion trend within a certain period in the future based on the determined potential corrosion points is as follows: (4.1) Obtain two-dimensional grid data and three-dimensional point cloud models of the surface structures of all potential corrosion points; (4.2) Map the two-dimensional grid data into the three-dimensional point cloud model to obtain the position data of the corrosion points, and import the position data of the corrosion points into BIM software to generate a three-dimensional corrosion point skeleton model; (4.3) Combine the infrared thermal imaging data of the steel bar scanner. The areas with abnormal temperature indicate the presence of rust expansion cracks. At the same time, combine ultrasonic testing to show the areas of internal cavities in the concrete and the debonding between the steel bars. Finally, generate a three-dimensional comprehensive corrosion point skeleton model; (4.4) Quantitatively determine the corrosion degree: Calculate the cross-sectional area loss of the steel bar according to the signal attenuation rate:
[0010] In the above formula, represents the cross-sectional area loss of the steel bar. The larger the cross-sectional area loss, the more the structural bearing capacity decreases; is a proportionality coefficient determined by experimental calibration or experience, representing the cross-sectional area loss corresponding to a unit resistance change; represents the resistance value of the non-corroded steel bar, Represents the measured resistance value of the corroded steel bar; (4.5) Import the comprehensive corrosion point skeleton model constructed in step (4.3) and the corrosion degree determined quantitatively in step (4.4) into ANSYS to simulate the stress redistribution caused by corrosion and the degree of bearing capacity decline, and combine with environmental data to predict the corrosion diffusion trend in a certain future period.
[0011] Furthermore, in step (4.3), the process of predicting the corrosion diffusion trend in a certain future period by combining environmental data is as follows: (4.3.1) First, correct the diffusion coefficient :
[0012] In the above formula, is the chloride ion diffusion coefficient, is the environmental temperature, is the relative humidity, is the activation energy, is the molar gas constant; (4.3.2) Calculate the chloride ion penetration depth :
[0013] In the above formula, is the chloride ion surface concentration, represents the diffusion duration of chloride ions from the concrete surface to the steel bar position, i.e., the corrosion initiation time, represents the cumulative diffusion effect of chloride ions in the concrete; represents the characteristic length of chloride ion diffusion. When = the error function value is close to 0.95. At this time, it can be approximately considered that chloride ions have not penetrated to this depth; Therefore, set and calculate the corrosion initiation time where is the critical chloride ion concentration; (4.3.4) Calculate the corrosion current density :
[0014] (4.3.5)Calculate the annual corrosion depth :
[0015] In the above formula, is the molar mass of iron, 55.85 , density , Faraday constant , annual time ; (4.3.6) By synthesizing the results calculated in the foregoing steps, the corrosion depth, cross-sectional area loss, and remaining load-bearing capacity within a certain period of time are obtained.
[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The existing support and reinforcement technology has the disadvantage that the time for maintaining the integrity of the roadway is short. Due to the small and loose reserved protective coal pillar, affected by the water corrosion, penetration of the upper roadway, and the construction operations of large equipment, the integrity structure of the protective coal pillar is very easy to be damaged, resulting in the failure of the support of the anchor cable and I-beam. By using the support means of the present method, the coal pillar can be protected on both sides from the upper and lower roadways. At the same time, pouring, interception and other methods are used in the upper part to effectively prevent the wastewater of the working face from flowing into the coal pillar, ensuring the overall stability of the protective coal pillar.
[0017] In addition, by using the corrosion degree prediction method of the present invention, it can help the staff to predict the corrosion degree and durability of the steel beam in a timely and accurate manner, further ensuring the overall anti-corrosion function. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 is a schematic flow chart of the steps of the reinforcement method described in the present invention. DETAILED DESCRIPTION OF THE INVENTION
[0019] The present invention will be further described below in conjunction with specific embodiments.
[0020] As Figure 1 shown, the anti-corrosion reinforcement method for the interchange roadway of the loose coal pillar described in the present invention includes the following steps: (1) Determine the range of the interchange roadway to be reinforced, and use I-beams, I-beam sheds and shotcrete to support the interchange roadway. Among them, the length of the support anchor cable of the I-beam near the lower part of the interchange roadway is greater than the thickness of the protective coal pillar, and I-beams are added to the bottom plate of the upper part of the interchange roadway so that the anchor cables on both sides are tightened together; (2) After the I-beams on the upper part of the interchange roadway are tightened, waterproof materials are laid and poured in the interchange area. The strength grade of the poured concrete is C20, and the weight mix ratio of the concrete is cement: sand: gravel = 1: 2.15: 4.0, and the water-cement ratio is 0.60 - 0.63. The concrete materials are selected as P.O32.5R composite portland cement, medium-coarse river sand, and cobblestones with a particle size of 20 - 40mm, and the pouring thickness is 480 - 520mm; (3) Install iron drainage pipes in the drainage ditches within the upper range of the interchange roadway.
[0021] On this basis, multiple infrared thermal imaging steel bar scanners can also be installed in the interchange roadway. The reinforcement range of the interchange roadway is demarcated into a shallow reinforcement area and a deep reinforcement area. For the shallow reinforcement area, an electromagnetic induction type steel bar scanner is used, and for the deep reinforcement area, a ground penetrating radar steel bar scanner is used. At the same time, a multi-frequency electromagnetic scanner is used to distinguish the signal differences of steel bars with different corrosion degrees.
[0022] Furthermore, the shallow reinforcement area and the deep reinforcement area are divided in a grid manner. The positions, depths, and signal intensities of the steel bars are recorded regularly by two types of steel bar scanners respectively. Through the signals emitted by the multi-frequency electromagnetic scanner, potential corrosion points are located in the signal abnormal areas; The process of predicting the corrosion diffusion trend within a certain future period based on the determined potential corrosion points is as follows: (4.1) Obtain the two-dimensional grid data and three-dimensional point cloud model of the surface structure of all potential corrosion points; (4.2) Map the two-dimensional grid data into the three-dimensional point cloud model to obtain the position data of the corrosion points, and import the position data of the corrosion points into BIM software to generate a three-dimensional corrosion point skeleton model; (4.3) Combine the infrared thermal imaging data of the steel bar scanner. The area with abnormal temperature indicates the presence of rust expansion cracks. At the same time, combine ultrasonic testing to show the internal voids of the concrete and the area where the steel bars are debonded. Finally, generate a three-dimensional comprehensive corrosion point skeleton model; (4.4) Quantitatively determine the corrosion degree: Calculate the cross-sectional area loss of the steel bar according to the signal attenuation rate:
[0023] In the above formula, represents the cross-sectional area loss of the steel bar. The larger the cross-sectional area loss, the more the structural bearing capacity decreases; is the proportionality coefficient determined by experimental calibration or experience, representing the cross-sectional area loss corresponding to the unit resistance change; represents the resistance value of the non-corroded steel bar, represents the measured resistance value of the steel bar after corrosion; (4.5) Import the comprehensive corrosion point skeleton model constructed in step (4.3) and the corrosion degree quantitatively determined in step (4.4) into ANSYS to simulate the stress redistribution and the decrease in bearing capacity caused by corrosion, and combine with environmental data to predict the corrosion diffusion trend within a certain future period.
[0024] In step (4.3), the process of predicting the corrosion diffusion trend within a certain future period by combining environmental data is as follows: (4.3.1) First, correct the diffusion coefficient :
[0025] In the above formula, is the chloride ion diffusion coefficient, is the environmental temperature, is the relative humidity, is the activation energy, is the molar gas constant; (4.3.2) Chloride ion penetration depth Calculation:
[0026] In the above formula, is the chloride ion surface concentration, represents the diffusion duration of chloride ions from the concrete surface to the steel bar position, i.e., the corrosion initiation time, represents the cumulative diffusion effect of chloride ions in the concrete; represents the characteristic length of chloride ion diffusion. When = the error function value is close to 0.95. At this time, it can be approximately considered that chloride ions have not penetrated to this depth; Therefore, set to calculate the corrosion initiation time where, is the critical chloride ion concentration; (4.3.4) Calculate the corrosion current density :
[0027] (4.3.5) Calculate the annual corrosion depth :
[0028] In the above formula, is the molar mass of iron, 55.85 , density , Faraday constant , annual time ; (4.3.6) Combining the results calculated in the above steps, the corrosion depth, cross-sectional area loss, and remaining load-bearing capacity within a certain period of time are obtained.
Claims
1. An anti-corrosion reinforcement method for overpass roadways in a loose coal pillar body, characterized in that, The method includes the following steps: (1) Determine the range of the interchange roadway to be reinforced, and support the interchange roadway with I-beams, I-beam sheds and shotcrete. Among them, the length of the support anchor cable of the I-beam near the lower part of the interchange roadway is greater than the thickness of the protective coal pillar. Add I-beams to the bottom plate above the interchange roadway so that the anchor cables on both sides are tightened together; (2) After the I-beams above the interchange roadway are tightened, lay waterproof materials and pour them in the interchange area. The concrete materials are selected as composite Portland cement, river sand, and cobblestones with a particle size of 20-40 mm. The weight mix ratio is composite Portland cement: river sand: cobblestones = 0.8-2: 2.15-3.04: 4.0-5.2, the water-cement ratio is 0.60-0.63, and the pouring thickness is 480-520 mm; (3) Install a drain pipe in the water channel within the upper range of the interchange roadway and connect it to the outside of the interchange roadway.
2. The anti-corrosion reinforcement method for the overpass roadway in the loose coal pillar according to claim 1, characterized in that, There are multiple infrared thermal imaging steel bar scanners in the interchange roadway. The reinforcement range of the interchange roadway is demarcated into a shallow reinforcement area and a deep reinforcement area. For the shallow reinforcement area, an electromagnetic induction type steel bar scanner is used. For the deep reinforcement area, a ground penetrating radar steel bar scanner is used. At the same time, a multi-frequency electromagnetic scanner is used to distinguish the signal differences of steel bars with different corrosion degrees.
3. The anti-corrosion reinforcement method for the overpass roadway in the loose coal pillar according to claim 2, characterized in that, The shallow reinforcement area and the deep reinforcement area are divided in a grid manner. The positions, depths and signal intensities of the steel bars are recorded regularly by the two types of steel bar scanners respectively. Through the signals emitted by the multi-frequency electromagnetic scanner, potential corrosion points are located for signal abnormal areas; The process of predicting the corrosion diffusion trend within a certain period in the future based on the determined potential corrosion points is as follows: (4.1) Obtain the two-dimensional grid data and three-dimensional point cloud model of the surface structure of all potential corrosion points; (4.2) Map the two-dimensional grid data into the three-dimensional point cloud model to obtain the position data of the corrosion points, and import the position data of the corrosion points into BIM software to generate a three-dimensional corrosion point skeleton model; (4.3) Combine the infrared thermal imaging data of the steel bar scanner. The area with abnormal temperature indicates the presence of rust expansion cracks. At the same time, combine ultrasonic detection to show the areas of internal cavities in the concrete and debonding between the steel bars. Finally, generate a three-dimensional comprehensive corrosion point skeleton model; (4.4) Quantitatively determine the degree of corrosion: Calculate the loss of the cross-sectional area of the steel bar according to the signal attenuation rate: In the above formula, represents the cross-sectional area loss of the steel bar. The larger the cross-sectional area loss, the more the structural bearing capacity decreases; is a proportionality coefficient determined by experimental calibration or experience, representing the cross-sectional area loss corresponding to the change in unit resistance; represents the resistance value of the uncorroded steel bar, represents the measured resistance value of the corroded steel bar; (4.5) Import the comprehensive corrosion point skeleton model constructed in step (4.3) and the degree of corrosion quantitatively determined in step (4.4) into ANSYS to simulate the stress redistribution caused by corrosion and the degree of decline in bearing capacity, and combine environmental data to predict the corrosion diffusion trend within a certain period in the future.
4. The anti-corrosion reinforcement method for the overpass roadway in the loose coal pillar according to claim 3, characterized in that, In step (4.3), the process of predicting the corrosion diffusion trend within a certain period in the future by combining environmental data is as follows: (4.3.1) First, correct the diffusion coefficient : In the above formula, is the chloride ion diffusion coefficient, is the environmental temperature, is the relative humidity, is the activation energy, is the molar gas constant; (4.3.2)Chloride ion penetration depth Calculation: In the above formula, is the surface concentration of chloride ions, represents the diffusion duration of chloride ions from the concrete surface to the steel bar position, that is, the corrosion initiation time, represents the cumulative diffusion effect of chloride ions diffusing in the concrete; represents the characteristic length of chloride ion diffusion. When = the error function value is close to 0.
95. At this time, it can be approximately considered that chloride ions have not penetrated to this depth; Thus, set to calculate the corrosion start time , where is the critical chloride ion concentration; (4.3.4)Calculation of corrosion current density : (4.3.5)Calculation of annual corrosion depth :[[]]END]] In the above formula, is the molar mass of iron, 55.85 , density , Faraday's constant , annual time ; (4.3.6) Synthesize the results calculated in the previous steps to obtain the predicted corrosion depth, cross-sectional area loss and remaining bearing capacity within a certain time.