A method for repairing a main track section embedded part of a dam hole emergency access door groove

Abstract

The application discloses a method for repairing a buried part of a main rail section of a dam middle hole accident access door groove, and the method comprises the following steps: repairing a damaged corner plate part by backfilling modified epoxy mortar, restoring a damaged sealing plate structure by planting a steel bar, and filling high-strength non-shrinkage grouting material behind the sealing plate. The repairing method maximally restores the original state, strengthens the structure of the main rail section of the accident access door groove, improves the repairing efficiency and quality under the condition of ensuring the operation safety of the door groove, further ensures the operation safety of the dam in the flood season, and has great economic benefits.

Description

Technical Field

[0001] This invention relates to the field of hydropower dam construction technology, and in particular to a method for repairing the embedded parts of the main rail section of the gate slot of an accident inspection gate in the middle hole of a dam. Background Technology

[0002] Dams are the core structures in hydropower projects, and the spillway gates are crucial components, directly impacting the operational safety of the dam and the entire project. Concrete dams typically have a number of intermediate or deep gates in the lower part of the dam body to discharge floodwaters during the flood season, ensuring the structural safety of the dam. The spillway gate's accident repair and maintenance section is complex, technically challenging, and requires high construction quality. During operation, especially under conditions of high sediment content and abnormal operation, it is susceptible to hydraulic damage. Damage to the main track section of the repair and maintenance gate primarily manifests as: the removal of embedded parts such as sealing plates and corner guards; and large, deep pits formed by secondary concrete erosion on the back of the main track, sealing plates, and corner guards, severely affecting the overall structural safety of the gate. Given that the main rail section of the inspection gate is connected to the reservoir, and that the lower flange of the gate leaf is very close to the main rail (generally about 90mm) when the water is blocked, the space is small, making repair difficult and difficult to carry out according to the original construction period design plan. If the repair process is not handled carefully, it may cause secondary damage, which will seriously threaten the structural safety of the dam. Summary of the Invention

[0003] The main objective of this invention is to provide a method for repairing the embedded parts of the main track section of the gate slot in a dam's central maintenance gate. The method involves backfilling the damaged corner guard plate with modified epoxy mortar, restoring the structure of the damaged sealing plate by installing reinforcing bars, and filling the back of the sealing plate with high-strength, non-shrink grouting material. This repair method closely approximates the original state and strengthens the structure of the main track section of the gate slot. It improves repair efficiency and quality while ensuring the safe operation of the gate slot, thereby guaranteeing the safe operation of the dam during the flood season and offering significant economic benefits.

[0004] To achieve the above-mentioned technical features, the objective of this invention is as follows: a method for repairing the embedded parts of the main rail section of the gate slot of a dam's central hole accident inspection gate, comprising the following steps: Step 1: Repair or replace the water seal in advance as needed to address the leakage in the flood discharge central hole. After the supervising engineer approves the work, lower the inspection gate slot to the bottom of the gate slot to block water according to the operating procedures. Step 2: After the gate slot is blocked by water, open the arc-shaped working gate as required to drain the water flow inside the channel; Step 3: Construct a construction channel to enter the flow channel from the central hoist chamber. For downstream upturned flow channels, a water pump needs to be installed to pump water and keep the flow channel free of water accumulation. This step can be skipped for flat-bottomed flow channels. Step 4: Check for leaks in the gate leaf. If there are leaks in the gate leaf, use cotton wool, sandbags, and steel plates to cover and seal the leaks. Direct the water flow from the top of the gate to the gate drainage hole so that it drains to the bottom of the gate. Cover the entire gate with waterproof canvas. Step 5: Erect a scaffold on the damaged side of the door slot that needs repair and cover it with a rainproof cloth to ensure it is dry. Set up a water-retaining dike according to the actual water seepage situation of the door. The water-retaining dike is initially formed by stacking yellow mud bags to create a temporary water-retaining dike. Once the water level in the door slot repair area has dropped to its lowest point, a full water-retaining dike is formed by building it with bricks. The bottom and sides of the water-retaining dike are plastered with cement mortar. Ventilation and drying measures are implemented in the scaffolding erection and repair area to ensure that the construction environment in the door slot repair area is not affected by water flow and moisture. Protective rubber mats must be laid on the bottom of the steel lining at the construction site to prevent damage to the steel lining during the repair process. Step 6: Install rebar at the damaged end plate on the downstream side of the main cast steel rail. The rebar holes should be drilled by rotation. Hot-rolled ribbed ordinary steel bars should be used for the rebar. The rebar depth should meet the pull-out resistance requirements, and the exposed length should meet the welding length requirements for the restoration of the end plate. Using the upper undamaged door groove corner plate, the outer contour of the lower end plate is led out by hanging line for measurement. After drilling and fixing the rebar, use rebar adhesive or glue to fix it. Step 7: According to the design requirements, fabricate the sealing plate for the damaged area based on the dimensions measured in Step 6, using sections as the unit. The material of the sealing plate should be consistent with the original material before the damage. The end plate should be made of steel plate. After the rebar is installed, hang a line to mark the position of the sealing plate and measure and record the rebar position, spacing, sealing plate width, and end plate width. Then, use the measured data to cut the sealing plate and end plate, bevel it, and drill holes. The holes on the sealing plate corresponding to the rebar positions need to be determined according to the rebar situation, and the diameter of the holes on the sealing plate should not exceed 36mm. Before hoisting the sealing plate, a lifting lug should be welded to the top of the back of the sealing plate for hoisting and positioning. Step 8: After the rebar is installed, remove the loose parts of the concrete surface and clean the contaminants and loose particles in the removed area with an angle grinder or wire wheel; blow away the sand and dust on the surface with compressed air, then rinse with compressed water to make the concrete surface clean and dust-free, and finally dry the concrete surface with air and compressed air. Step 8: After the rebar installation and concrete surface roughening are completed, the sealing plates are installed, hoisting them into place sequentially from bottom to top. Before installing the last sealing plate, the relevant dimensions of the top curved corner guard need to be measured, and a cardboard mold needs to be made on site. Based on the measurement data and the mold, the sealing plate is cut and trimmed in the metal structure factory. Hoisting is carried out using a combination of hand-operated hoists and winches for traction, with manual assistance for positioning. After each sealing plate is hoisted into place, the rebar is first inserted through the rebar holes in the sealing plate. The ends of the rebars are then threaded and secured with pads. Temporarily fix the plates and bolts, then adjust the gaps at both ends and the bottom of the sealing plate. After adjustment, spot weld and reinforce with locking plates. Finally, tighten the reinforcing rib pads and bolts before hoisting the next sealing plate. When welding the sealing plates, prioritize welding the transverse seams between sections, then weld the contact points between the sealing plate and the steel lining, then weld the welds at the cast steel track pad positions, and finally weld the welds at the bottom sill and the contact points at the top steel lining corner guards. Leave a 5-7mm gap between the sealing plate and the main rail corner guard where the corner guards have not detached. The gaps are filled with epoxy mortar; after the sealing plate is welded, the cavity behind it is backfilled with high-strength non-shrink grout. After solidification, the pad and nut are removed, and the exposed part of the rebar is cut off. The rebar needs to be cut and ground down to a certain length below the sealing plate surface. Then, the rebar is connected to the sealing plate by plug welding and covered with stainless steel. After welding, it is ground flat. For cast steel track pads that are bent or broken, they need to be cut to the installation position first, straightened, and then welded tightly to the end plate of the sealing plate. Step nine: After each sealing plate is installed, use it as a template. Fill the cavities and gaps behind the sealing plate with high-strength, non-shrink grouting material. The last sealing plate is shorter than the original design. After installation, fill the high-strength, non-shrink grouting material through the pre-reserved opening at the top. During the grouting process, use the openings on the sealing plates as observation holes to observe the grouting situation and temporarily seal them with gauze. After the flood season, conduct a void inspection. After chemical grouting the voided areas, weld them back on. Step 10: After backfilling the cavity behind the sealing plate with high-strength non-shrink grout, remove the pad and nut after solidification, and cut off the part of the reinforcing bar that is exposed on the sealing plate. The reinforcing bar needs to be cut off and ground down to a certain length below the sealing plate surface. Then, the reinforcing bar is connected to the sealing plate by plug welding and covered with stainless steel. After welding, it is ground flat. For cast steel track pads that are bent or broken, they need to be cut to the installation position first, corrected, and then welded tightly to the end plate of the sealing plate. Step 11: Backfill the damaged areas on the outer side of the main track of the gate slot and the upstream side of the end plate of the sealing plate with epoxy mortar. After cleaning the cast steel track and the surface of the attached concrete, repeatedly apply a thin layer of epoxy interface agent. Before the air bubbles in the epoxy interface agent are eliminated and before initial setting, lay the epoxy mortar. Install a shaped plastic template as an outer template outside the epoxy mortar backfill repair area. The plastic template is reinforced with outer hoop steel walers. The shaped plastic template must have good demolding performance with the epoxy mortar and should not damage the epoxy mortar that has completely lost its plasticity during demolding. The thickness of each layer of modified epoxy mortar should not exceed 2cm, and it should be compacted and smoothed. The next layer of construction can only be carried out when the previous layer of epoxy mortar has completely lost its plasticity and no longer deforms. After installing 2 to 4 templates for the first time, flip them over one by one for construction. Step 12: After the epoxy mortar application is completed and all the molded plastic templates are demolded, keep the base surface clean. Use a scraper to apply a high-weather-resistant epoxy impact-resistant coating, controlling the coating thickness. The surface should be smoothed and leveled to meet the surface unevenness requirements. The flow surface shape after the high-weather-resistant epoxy impact-resistant coating is applied should be consistent with the flow shape designed for the original main rail sealing plate. After the epoxy mortar and impact-resistant coating materials are applied, ensure that they do not come into contact with standing water within 1 day and allow them to cure naturally for at least 3 days. After construction, take care to avoid direct collisions with the ends of steel components and sharp corners of the treads.

[0005] Preferably, the weld seam between the assembled welding end plate and the end plate needs to be ground with a V-shaped bevel. The angle between the end plate and the end plate should be 95°-100°. After adjustment, spot welding should be performed to fix it and locking plates should be added for welding reinforcement. When welding, first use A3.2mm stainless steel welding rod for the root pass, and then use A4.0mm stainless steel welding rod for the formal welding. After welding, it needs to be ground smooth. The inner side is a 10mm fillet weld, which is welded with A4.0mm stainless steel welding rod. The inner and outer sides need to be welded symmetrically to prevent deformation during welding.

[0006] Preferably, the weld seam between the sealing plate and the steel lining is beveled. When installing the sealing plate, a gap of 1mm-2mm is reserved between it and the steel lining. After adjustment, spot welding is performed to fix it and locking plates are added for welding reinforcement. When welding, A3.2mm stainless steel welding rods are used to weld the root pass first, and then A4.0mm stainless steel welding rods are used for the formal welding. After welding, it needs to be ground smooth.

[0007] Preferably, the butt weld joint of the sealing plate and the sealing plate is ground with a V-shaped bevel. When installing the sealing plate, a gap of 1mm-2mm is reserved between it and the steel lining. After adjustment, spot welding is performed to fix it and locking plates are added for welding reinforcement. When welding, A3.2mm stainless steel welding rods are used to weld the root pass first, and then A4.0mm stainless steel welding rods are used for formal welding. After welding, it needs to be ground flat.

[0008] Preferably, the stainless steel welding electrode is a CHS2209 stainless steel welding electrode.

[0009] Preferably, before backfilling with epoxy mortar, the concrete, rust, and other debris remaining on the cast steel track must be thoroughly cleaned to ensure that the base surface is dry and exposes the metallic luster, and then wiped clean with degreased cotton soaked in acetone.

[0010] Preferably, in step five, the cross-sectional dimensions of the water-retaining cofferdam are 25cm x 80cm.

[0011] Preferably, the ventilation and drying measures are ventilation using a fan or air compressor, or baking with an iodine-tungsten lamp.

[0012] Preferably, in step six, the spacing between the anchor holes is 500mm; the anchors are HRB335 hot-rolled ribbed ordinary steel bars with a diameter of 28mm and the anchor hole diameter is 50mm; the pull-out resistance of a single anchor is not less than 222kN.

[0013] Preferably, in step seven, the end plate is made of Q235B steel plate.

[0014] Preferably, in steps eight and ten, the rebar passes through the sealing plate with an exposed length of 90mm-110mm, and the end of the rebar is machined with an M24 thread; the rebar is cut and ground down to 4mm below the surface of the sealing plate.

[0015] Preferably, in step nine, the last sealing plate is 100mm shorter than the original design sealing plate.

[0016] Preferably, in step eleven, the thin-layer epoxy interface agent is thin and uniform, with a thickness of 0.1mm-0.2mm.

[0017] Preferably, the width of the single-piece shaping plastic template in step eleven is 30cm.

[0018] The present invention has the following beneficial effects: 1. This invention repairs damaged corner guards by backfilling with modified epoxy mortar, which can quickly achieve high strength and complete the repair, ensuring a smooth transition, smooth water flow, and reducing erosion of the door groove; 2. This invention restores the structure of the damaged sealing plate by installing rebar at the damaged sealing plate location and fills the back of the sealing plate with high-strength non-shrink grouting material. This can restore the sealing plate and its secondary concrete to the greatest extent possible, and also strengthens the main track section structure of the gate slot for accident repair. It improves repair efficiency and quality while ensuring the safe operation of the gate slot, thereby ensuring the safe operation of the dam during the flood season and has significant economic benefits. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Figure 1 This is a diagram of the sealing plate installation of the present invention.

[0021] Figure 2 This is the present invention. Figure 1 Rotating view II.

[0022] Figure 3 This is the present invention. Figure 1 Rotating view II-II.

[0023] Figure 4 This is the present invention. Figure 1 Rotating view of section III-III.

[0024] Figure 5 This is the present invention. Figure 2 A partial view of A in the middle.

[0025] Figure 6 This is the present invention. Figure 2 Partial view B before grouting material is filled.

[0026] Figure 7 This is the present invention. Figure 2 Partial view B after the grouting material has been filled.

[0027] Figure 8 This is a diagram of the present invention. Figure 4 A partial view in C.

[0028] Figure 9 This is a diagram of the present invention. Figure 4 A partial view in D.

[0029] Figure 10 This is the main view of the sealing plate of the present invention.

[0030] Figure 11 This is the present invention. Figure 10 View 1-1 in the middle.

[0031] Figure 12 This is the present invention. Figure 11 Enlarged view of part of E in the middle.

[0032] Figure 13 This is a diagram of the weld seam between the in-plant welding sealing plate and the end plate of this invention.

[0033] Figure 14 This is a diagram of the weld between the sealing plate and the steel lining of this invention.

[0034] Figure 15 This is a diagram of the butt weld between the sealing plates of the present invention.

[0035] In the diagram: 1. Main rail; 2. Steel lining; 3. Sealing plate; 4. Corner guard plate; 5. Second-stage concrete; 6. First-stage concrete; 7. First-section repair sealing plate 301; 8. Second-section repair sealing plate 302; 9. Third-section repair sealing plate 303; 10. Fourth-section repair sealing plate 304; 10. Epoxy mortar; 11. High-strength non-shrink grouting material; 22. Rebar installation; 33. Rebar installation hole. Detailed Implementation

[0036] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0037] like Figure 1-15 As shown, a method for repairing the embedded parts of the main rail section of the gate slot of an accident inspection gate in a dam's central opening includes the following steps: Step 1: Repair or replace the water seal in advance as needed to address the leakage in the flood discharge central hole. After the supervising engineer approves the work, lower the inspection gate slot to the bottom of the gate slot to block water according to the operating procedures. Step 2: After the gate slot is blocked by water, open the arc-shaped working gate as required to drain the water flow inside the channel; Step 3: Construct a construction channel to enter the flow channel from the central hoist chamber. For downstream upturned flow channels, a water pump needs to be installed to pump water and keep the flow channel free of water accumulation. This step can be skipped for flat-bottomed flow channels. Step 4: Check for leaks in the gate leaf. If there are leaks in the gate leaf, use cotton wool, sandbags, and steel plates to cover and seal the leaks. Direct the water flow from the top of the gate to the gate drainage hole so that it drains to the bottom of the gate. Cover the entire gate with waterproof canvas. Step 5: Erect a scaffold on the side of the door groove that needs repair and cover it with a rainproof cloth to ensure it is dry. Set up a water-retaining dike according to the actual water seepage situation of the door. First, use yellow mud bags to form a temporary water-retaining dike. After the water level in the door groove repair area drops to its lowest level, build a full water-retaining dike with bricks. Apply cement mortar to the bottom and sides of the water-retaining dike. Implement ventilation and drying measures in the scaffolding repair area to ensure that the construction environment in the door groove repair area is not affected by water flow and moisture. The bottom of the steel lining 2 at the construction site should be covered with a protective rubber mat to prevent damage to the steel lining 2 during the repair process. Step 6: Install rebar at the damaged end plate 3 on the downstream side of the main rail 1 cast steel track. The rebar holes should be drilled by rotation. Hot-rolled ribbed ordinary steel bars should be used for the rebar 9. The depth of the rebar 9 should meet the pull-out resistance requirements, and the exposed length should meet the welding length requirements of the end plate 3. Using the upper undamaged door groove corner plate 4, the outer contour of the lower end plate is led out by hanging line for measurement. After drilling and fixing the rebar 9, use rebar glue or adhesive to fix it. Step 7: According to the design requirements, fabricate the sealing plate 3 of the damaged area as measured in Step 6, in sections. The material of the sealing plate should be consistent with the original material before the damage. The end plate should be made of steel plate. After the rebar is installed, hang a line at the position of the sealing plate and measure and record the rebar position, spacing, sealing plate width, and end plate width. Then, cut the sealing plate and end plate according to the measured data, bevel the edges, and drill holes. The hole on the sealing plate 3 corresponding to the position through which the rebar 9 passes should be determined according to the rebar situation. The diameter of the hole on the sealing plate should not exceed 36mm. Before hoisting the sealing plate 3, a lifting lug should be welded to the top of the back of the sealing plate for hoisting and positioning. Step 8, after the rebar installation is completed, remove the loose parts of the concrete surface and clean the contaminants and loose particles at the removed area with an angle grinder or wire wheel; blow away the sand and dust on the surface with compressed air, then rinse with compressed water to make the concrete surface clean and dust-free, and finally dry the concrete surface with air drying and compressed air blowing. Step 8: After the rebar installation and concrete surface roughening are completed, install the sealing plate 3. Hoist the plates in place sequentially from bottom to top. Before installing the last sealing plate, measure the relevant dimensions of the top curved corner guards and create a cardboard mold on-site. Based on the measurement data and the mold, cut and trim the sealing plate at the metal structure factory. Hoisting is assisted by a hand-operated hoist and winch, with manual assistance for positioning. After each sealing plate is in place, insert the rebar 9 through the rebar holes in the sealing plate. Thread the ends of the rebar 9. Temporarily fix the pads and bolts, then adjust the gaps at both ends and the bottom of the sealing plate. After adjustment, spot weld and reinforce with locking plates. Finally, tighten the reinforcing bar pads and bolts before hoisting the next sealing plate. When welding the sealing plates, prioritize welding the transverse seams between sections, then weld the contact points between the sealing plate and steel lining 2, then weld the welds at the cast steel track pad positions, and finally weld the welds at the bottom sill and the contact points at the top steel lining 2 corner guards. Leave a 5-7mm gap between the sealing plate and the main rail corner guard at the part of the corner guard 4 that has not fallen off. The gaps are filled with epoxy mortar 7; after the sealing plate is welded, the cavity behind it is backfilled with high-strength non-shrink grout 8. After solidification, the pad and nut are removed, and the exposed part of the reinforcing bar 9 is cut off. The reinforcing bar 9 needs to be cut off and ground to a certain length below the sealing plate surface. Then, the reinforcing bar 9 is connected to the sealing plate by plug welding and covered with stainless steel. After welding, it is ground flat. For cast steel track pads that are bent or broken, they need to be cut to the installation position first, straightened, and then welded tightly to the end plate of the sealing plate. Step nine: After each sealing plate is installed, use the sealing plate as a template. Fill the cavity and gaps behind the sealing plate with high-strength non-shrink grouting material 8. The last sealing plate is shorter than the original design sealing plate. After installation, fill the high-strength non-shrink grouting material 8 through the pre-reserved opening at the top. During the grouting process, use the opening on the sealing plate as an observation hole to observe the grouting situation and temporarily seal it with gauze. After the flood season, conduct a void check. After the voided areas are chemically grouted, weld the sealing plate back on. Step 10: After backfilling the cavity behind the sealing plate with high-strength non-shrink grout material 8, remove the pad and nut after solidification, and cut off the part of the reinforcing bar that is exposed on the sealing plate. The reinforcing bar needs to be cut off and ground to a certain length below the sealing plate surface. Then, the reinforcing bar is connected to the sealing plate by plug welding and covered with stainless steel. After welding, it is ground flat. For cast steel track pads that are bent or broken, they need to be cut to the installation position first, corrected, and then welded tightly to the end plate of the sealing plate. Step 11: Backfill the damaged areas on the outer side of the main track of the gate slot and the upstream side of the end plate with epoxy mortar 7. After cleaning the cast steel track and the surface of the attached concrete, repeatedly apply a thin layer of epoxy interface agent. Before the air bubbles in the epoxy interface agent are eliminated and before initial setting, lay the epoxy mortar. Install a shaped plastic template as an outer template outside the epoxy mortar backfill repair area. The plastic template is reinforced with outer hoop steel walers. The shaped plastic template must have good demolding performance with the epoxy mortar and should not damage the epoxy mortar that has completely lost its plasticity during demolding. The thickness of each layer of modified epoxy mortar should not exceed 2cm, and it should be compacted and smoothed. The next layer of construction can only be carried out when the previous layer of epoxy mortar has completely lost its plasticity and no longer deforms. After installing 2 to 4 templates for the first time, flip them over one by one for construction. Step 12: After the epoxy mortar application is completed and all the molded plastic templates are demolded, keep the base surface clean. Use a scraper to apply a high-weather-resistant epoxy impact-resistant coating, controlling the coating thickness. The surface should be smoothed and leveled to meet the surface unevenness requirements. The flow surface shape after the high-weather-resistant epoxy impact-resistant coating is applied should be consistent with the flow shape designed for the original main rail sealing plate. After the epoxy mortar and impact-resistant coating materials are applied, ensure that they do not come into contact with standing water within 1 day and allow them to cure naturally for at least 3 days. After construction, take care to avoid direct collisions with the ends of steel components and sharp corners of the treads.

[0038] Example 2: See Figure 13The weld seam between the assembly and welding of the end plate and the end plate needs to be ground with a V-shaped bevel. The angle between the end plate and the end plate should be 95°-100°. After adjustment, spot welding should be performed to fix it and locking plates should be added for welding reinforcement. When welding, first use A3.2mm stainless steel welding rods for the root pass, and then use A4.0mm stainless steel welding rods for the final welding. After welding, it needs to be ground smooth. The inner side is a 10mm fillet weld, which is welded with A4.0mm stainless steel welding rods. The inner and outer sides need to be welded symmetrically to prevent deformation during welding.

[0039] Example 3: See Figure 14 The weld seam between the sealing plate and the steel lining 2 should be beveled. When installing the sealing plate, leave a 1mm-2mm gap between it and the steel lining 2. After adjustment, spot weld to fix it and add a locking plate for welding reinforcement. When welding, first use A3.2mm stainless steel welding rod to weld the root pass, and then use A4.0mm stainless steel welding rod for the formal welding. After welding, it needs to be ground smooth.

[0040] Example 4: See Figure 15 The sealing plate should be ground into a V-shaped bevel at the butt weld position. When installing the sealing plate, leave a 1mm-2mm gap between it and the steel lining. After adjustment, spot weld to fix it and add a locking plate for welding reinforcement. When welding, first use A3.2mm stainless steel welding rod to weld the root pass, and then use A4.0mm stainless steel welding rod for the formal welding. After welding, it needs to be ground smooth.

[0041] Preferably, the stainless steel welding electrode is a CHS2209 stainless steel welding electrode.

[0042] Preferably, before backfilling with epoxy mortar, the concrete, rust, and other debris remaining on the cast steel track must be thoroughly cleaned to ensure that the base surface is dry and exposes the metallic luster, and then wiped clean with degreased cotton soaked in acetone.

[0043] Preferably, in step five, the cross-sectional dimensions of the water-retaining cofferdam are 25cm x 80cm.

[0044] Preferably, the ventilation and drying measures are ventilation using a fan or air compressor, or baking with an iodine-tungsten lamp.

[0045] Preferably, in step six, the spacing between the anchor holes is 500mm; the anchor 9 uses HRB335 hot-rolled ribbed ordinary steel bars with a diameter of 28mm and an anchor hole diameter of 50mm; the pull-out resistance of a single anchor 9 is not less than 222kN.

[0046] Preferably, in step seven, the end plate is made of Q235B steel plate.

[0047] Preferably, in steps eight and ten, the reinforcing bar 9 passes through the sealing plate with an exposed length of 90mm-110mm, and the end of the reinforcing bar 9 is machined with an M24 thread; the reinforcing bar 9 is cut and ground down to 4mm below the surface of the sealing plate.

[0048] Preferably, in step nine, the last sealing plate is 100mm shorter than the original design sealing plate.

[0049] Preferably, in step eleven, the thin-layer epoxy interface agent is thin and uniform, with a thickness of 0.1mm-0.2mm.

[0050] Preferably, the width of the single-piece shaping plastic template in step eleven is 30cm.

[0051] Example 5: In this embodiment, the main performance parameters of the epoxy cross-linking agent used are shown in Table 4-1, the main performance indicators of the modified epoxy mortar are shown in Table 4-2, and the main performance indicators of the high weather-resistant epoxy impact-resistant and wear-resistant coating are shown in Table 4-3.

[0052]

[0053] Example 6: High-strength, non-shrink grouting material mixing ratio:

Claims

1. A method for repairing the embedded parts of the main rail section of the gate slot of an accident inspection gate in a dam's central opening, characterized in that, It includes the following steps: Step 1: Repair or replace the water seal in advance as needed to address the leakage in the flood discharge central hole. After the supervising engineer approves the work, lower the inspection gate slot to the bottom of the gate slot to block water according to the operating procedures. Step 2: After the gate slot is blocked by water, open the arc-shaped working gate as required to drain the water flow inside the channel; Step 3: Construct a construction passage to enter the flow channel from the central hoist chamber. For downstream upturned flow channels, a water pump needs to be installed to pump water and keep the flow channel free of water accumulation. If it is a flat-bottomed flow channel, skip this step. Step 4: Check for leaks in the gate leaf. If there are leaks in the gate leaf, use cotton wool, sandbags, and steel plates to cover and seal the leaks. Direct the water flow from the top of the gate to the gate drainage hole so that it drains to the bottom of the gate. Cover the entire gate with waterproof canvas. Step 5: Erect a scaffold on the side of the door groove that needs repair and cover it with a rainproof cloth to ensure that the scaffold is dry. Set up a water-blocking dike according to the actual water seepage situation of the door body. First, use yellow mud bags to form a temporary water-blocking dike. When the water level in the door groove repair construction area drops to the lowest level, then build a water-blocking dike with bricks. Apply cement mortar to the bottom and all sides of the water-blocking dike. Arrange ventilation and drying measures in the scaffolding construction area to ensure that the construction environment in the door groove repair construction area is not affected by water flow and water vapor. The bottom of the steel lining (2) of the construction part needs to be covered with a protective rubber pad to prevent damage to the steel lining (2) during the repair process. Step 6: Install rebar at the damaged end plate (3) on the downstream side of the main rail (1) cast steel rail. The rebar holes should be constructed by rotation. Hot-rolled ribbed ordinary steel bars should be used for the rebar (9). The depth of the rebar (9) should meet the pull-out resistance requirements, and the exposed length should meet the welding length requirements of the end plate (3). Using the upper undamaged door groove corner plate (4), the outer contour of the end plate below is led out by hanging line for measurement. After drilling and fixing the rebar (9), use rebar glue or adhesive to fix it. Step 7: According to the design requirements, the damaged sealing plate (3) is made in sections according to the dimensions measured in Step 6. The material of the sealing plate is consistent with the original material before the damage. The end plate is made of steel plate. After the rebar is installed, the sealing plate position is marked with a line. The rebar position, spacing, sealing plate width, and end plate width are measured and recorded. Then, the sealing plate and end plate are cut, beveled, and drilled according to the measured data. The hole on the sealing plate (3) corresponding to the position through the rebar (9) needs to be determined according to the rebar situation. The diameter of the hole on the sealing plate does not exceed 36mm. Before hoisting the sealing plate (3), a lifting lug needs to be welded on the top of the back of the sealing plate for hoisting the sealing plate into place. Step 8, after the rebar (9) is installed, remove the loose parts of the concrete surface and clean the contaminants and loose particles at the removed area with an angle grinder or wire wheel; blow away the sand and dust on the surface with compressed air, then rinse with compressed water to make the concrete surface clean and dust-free, and finally dry the concrete surface with air drying and compressed air blowing. Step 9: After the rebar installation and concrete surface roughening are completed, the sealing plate (3) is installed. It is hoisted into place from bottom to top. Before the last sealing plate is installed, the relevant dimensions of the top arc corner guard need to be measured. A cardboard mold is made on site. According to the measurement data and the mold, the sealing plate is cut and trimmed in the metal structure factory. The hoisting is carried out with the help of a hand hoist and a winch. The sealing plate is positioned manually. After each sealing plate is hoisted into place, the rebar (9) is passed through the rebar hole of the sealing plate. The rebar (9) is passed through the sealing plate. The end of the rebar (9) is threaded and temporarily fixed with a pad and bolt. Then the gap between the two ends and the bottom of the sealing plate is adjusted. After completion, spot welding is performed for fixation, and locking plates are added for reinforcement. Finally, the anchor plate and bolts are tightened before hoisting the next sealing plate. When welding the sealing plate, the inter-section transverse seam is welded first, then the contact position between the sealing plate and the steel lining (2) is welded, then the weld at the position of the cast steel track pad is welded, and finally the weld at the bottom sill position and the contact position of the top steel lining (2) corner guard is welded. The 5-7mm gap between the sealing plate and the main rail corner guard plate in the part of the corner guard plate (4) that has not fallen off is filled with epoxy mortar (7). For cast steel track pads that are bent or broken, they need to be cut to the installation position first, corrected, and then welded close to the end plate of the sealing plate. Step 10: After each sealing plate is installed, the sealing plate is used as a template. The cavity and gap behind the sealing plate are filled with high-strength non-shrink grouting material (8). The last sealing plate is shorter than the original design sealing plate. After installation, the top reserved opening is used to fill the high-strength non-shrink grouting material (8). During the grouting process, the opening of the sealing plate is used as an observation hole to observe the grouting situation, and the opening is temporarily sealed with gauze. After the flood season, a void inspection will be conducted, and the voided areas will be chemically grouted before being welded shut. Step 11: After backfilling the cavity behind the sealing plate with high-strength non-shrink grouting material (8), remove the pad and nut after solidification, and cut off the part of the reinforcing bar (9) that is exposed on the sealing plate. The reinforcing bar (9) needs to be cut off and ground down to a certain length below the sealing plate surface. Then, the reinforcing bar (9) is connected to the sealing plate by plug welding and covered with stainless steel. After welding, it is ground flat. Step 12: The damaged areas on the outer side of the main track of the gate slot and the upstream side of the sealing plate end plate are backfilled with epoxy mortar (7). After the cast steel track and the surface of the attached concrete are cleaned, a thin layer of epoxy interface agent is repeatedly applied. Epoxy mortar is laid before the air bubbles in the epoxy interface agent are eliminated and before the initial setting. A fixed plastic template is installed on the outer side of the epoxy mortar backfill repair area as an outer template. The plastic template is reinforced by the outer hoop steel bar waler. The shaped plastic formwork must have good demolding performance with epoxy mortar, and should not damage the epoxy mortar that has completely lost its plasticity during demolding; the thickness of each layer of modified epoxy mortar should not exceed 2cm, and it should be compacted and smoothed. The next layer of construction can only be carried out when the previous layer of epoxy mortar has completely lost its plasticity and no longer deforms; after the first installation of 2 to 4 formwork pieces, the formwork should be flipped over one by one for construction. Step 13: After the epoxy mortar application is completed and all the molded plastic templates are demolded, keep the base surface clean. Use a scraper to apply a high-weather-resistant epoxy anti-abrasion coating, controlling the coating thickness. The surface should be smoothed and leveled to meet the surface unevenness requirements. The flow surface shape after the high-weather-resistant epoxy anti-abrasion coating is applied should be consistent with the flow shape designed for the original main rail sealing plate. After the epoxy mortar and anti-abrasion coating materials are applied, ensure that they do not come into contact with standing water within 1 day and allow them to cure naturally for at least 3 days. After construction, take care to avoid direct collisions with the ends of steel components and sharp corners of the treads.

2. The method for repairing the embedded parts of the main rail section of the gate slot of a dam's central hole accident inspection gate according to claim 1, characterized in that: The weld seam between the assembled and welded end plate and the end plate needs to be ground with a V-shaped bevel. The angle between the end plate and the end plate should be 95°-100°. After adjustment, spot welding should be performed to fix it. After adding a locking plate, welding reinforcement should be carried out. When welding, first use A3.2mm stainless steel welding rod for the root pass, and then use A4.0mm stainless steel welding rod for the final welding. After welding, it needs to be ground smooth. The inner side is a 10mm fillet weld, which is welded with A4.0mm stainless steel welding rod. The inner and outer sides need to be welded symmetrically to prevent deformation during welding.

3. The method for repairing the embedded parts of the main rail section of the gate slot of a dam's central hole accident inspection gate according to claim 1, characterized in that: The weld seam between the sealing plate and the steel lining (2) is beveled. When the sealing plate is installed, a gap of 1mm-2mm is reserved between it and the steel lining (2). After adjustment, spot welding is performed to fix it. After adding the locking plate, welding is performed to reinforce it. When welding, A3.2mm stainless steel welding rod is used to weld the root first, and then A4.0mm stainless steel welding rod is used for formal welding. After welding, it needs to be ground flat.

4. The method for repairing the embedded parts of the main rail section of the gate slot of a dam's central hole accident inspection gate according to claim 1, characterized in that: Grind a V-shaped bevel at the butt weld position of the sealing plate and the sealing plate. When installing the sealing plate, leave a 1mm-2mm gap between it and the steel lining (2). After adjustment, spot weld to fix it, and then add a locking plate for welding reinforcement. When welding, first use A3.2mm stainless steel welding rod to weld the root, and then use A4.0mm stainless steel welding rod for formal welding. After welding, it needs to be ground flat.

5. A method for repairing the embedded parts of the main rail section of the gate slot of an accident inspection gate in a dam as described in claim 2, 3, or 4, characterized in that: The stainless steel welding electrode used is CHS2209 stainless steel welding electrode.

6. The method for repairing the embedded parts of the main rail section of the gate slot of an accident inspection gate in a dam as described in claim 1, characterized in that: Before backfilling with epoxy mortar, the concrete, rust, and other debris remaining on the cast steel track must be thoroughly cleaned to ensure that the base surface is dry and exposes the metallic luster. The track should then be cleaned with degreased cotton soaked in acetone.

7. The method for repairing the embedded parts of the main rail section of the gate slot of an accident inspection gate in a dam as described in claim 1, characterized in that: In step five, the cross-sectional dimensions of the water-retaining cofferdam are 25cm wide × 80cm high; The ventilation and drying measures include ventilation using fans and air compressors or baking with iodine-tungsten lamps.

8. The method for repairing the embedded parts of the main rail section of the gate slot of an accident inspection gate in a dam as described in claim 1, characterized in that: In step six, the spacing between the anchor holes is 500mm; the anchor (9) uses HRB335 hot-rolled ribbed ordinary steel bars with a diameter of 28mm and an anchor hole diameter of 50mm; the pull-out force of a single anchor (9) is not less than 222kN.

9. A method for repairing the embedded parts of the main rail section of the gate slot of an accident inspection gate in a dam's central opening, as described in claim 1, is characterized in that: In step seven, the end plate is made of Q235B steel plate; In step eleven, the reinforcing bar (9) passes through the sealing plate with an exposed length of 90mm-110mm, and the end of the reinforcing bar (9) is machined with an M24 thread; the reinforcing bar (9) is cut and ground down to 4mm below the surface of the sealing plate. In step ten, the last sealing plate is 100mm shorter than the original design sealing plate.

10. The method for repairing the embedded parts of the main rail section of the gate slot of an accident inspection gate in a dam's central opening according to claim 1, characterized in that: In step twelf, the thin-layer epoxy interface agent is thin and uniform, with a thickness of 0.1mm-0.2mm; In step twelve, the width of a single shaped plastic template is 30cm.

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