Non-excavation repairing method for defects in large-pipe-diameter drainage pipeline

Abstract

The invention belongs to the technical field of drainage pipeline repairing, and particularly relates to a non-excavation repairing method for defects in a large-pipe-diameter drainage pipeline. Comprising the steps of prefabricating a steel formwork, plugging and guiding water in a drainage pipeline, dredging and detecting the interior of the pipeline, conducting ventilation testing, enabling constructors to go down a well for operation, chiseling defect positions, cleaning and removing loose parts and garbage, brushing a concrete interface agent, positioning, installing and fastening the steel formwork, connecting a grouting pipe and grouting equipment, preparing a grouting material, and then conducting pressure grouting. The method for repairing the defects in the drainage pipeline has the advantages that the grouting technology is applied to repairing of the defects in the drainage pipeline, the repairing quality is improved, and the manufacturing cost is saved.

Description

Technical Field

[0001] The invention relates to the technical field of drainage pipe repair, and in particular to a trenchless repair method for defects in a large-diameter drainage pipe. Background Art

[0002] At present, the built-up area's rainwater and sewage drainage has been tested through dredging (CCTV testing), and it has been found that large-diameter (not less than 800m) concrete drainage pipes have many local defects such as cracks, misalignment, and disconnection, which cause pollution to the surrounding environment and soil. At present, non-excavation local repairs are mostly used for such local defects. The three mainstream construction methods in China are stainless steel quick lock, point-shaped in-situ solidification method, and stainless steel double expansion ring. The construction principle of these methods is to line the original pipe with rings of different materials locally, so there are different degrees of water flow section loss; secondly, after the lining ring is used for a long time in a complex environment, there are problems such as material shedding, which increases the risk of water blocking and construction cost, and affects the drainage function of the drainage pipe; although there is currently polymer mortar grouting technology, it is rarely used in combination with drainage pipe repair, and there are defects such as low strength and easy shedding. Summary of the invention

[0003] The present invention is aimed at the above-mentioned problems and specifically designs a trenchless repair method for defects in large-diameter drainage pipes, so that grouting technology is applied to the repair of defects in drainage pipes, thereby improving the repair quality and saving construction costs.

[0004] To achieve the above object, the present invention provides a trenchless repair method for defects in a large-diameter drainage pipe, comprising the following steps: Step 1: Prefabricate an assembled steel template that matches the inner diameter of the drainage pipe. The steel template is pre-equipped with grouting holes, exhaust holes, and grouting fullness verification holes; Step 2: Block and guide the drainage pipe, remove silt and inspect the pipe to determine the location and extent of the internal defects. After the pipe is cleaned, the construction personnel will ventilate and inspect it, and start the operation after the conditions for going down the well are met; Step 3: After the construction workers arrive at the exact location of the defect, they will roughen the defect, clean and remove loose parts and garbage, wash the defect with clean water, dry it and apply concrete interface agent; Step 4: Position, install and tighten the steel formwork; Step 5. Connect the grouting pipe and grouting equipment, prepare the slurry according to the manufacturer's mix ratio, and the stirring time should be no less than 5 minutes. After stirring, let it stand for 1-2 minutes. After the bubbles disappear, perform pressure grouting until the grouting fullness verification hole overflows with slurry for 1 minute; Step 6: Remove the steel formwork and clean up the site 30 minutes after the grouting material has finally set.

[0005] Furthermore, in the step 1, the steel template includes a plurality of groups of arc-shaped templates that are assembled and fixed in sequence, each arc-shaped template is provided with screw holes, and adjacent arc-shaped templates are fixed by connecting pieces.

[0006] Furthermore, in step one, a radial groove is provided on the arc-shaped template near the drainage pipe side, and a rubber waterstop is sandwiched between the arc-shaped template and the drainage pipe.

[0007] Furthermore, in the step one, a plurality of groups of grouting range limit blocks are movably arranged in the groove.

[0008] Furthermore, in the step 2, a water-blocking airbag is used to block the upstream section of the pipeline defect, and the blocking airbag is connected to an air pump through an air pipe, and a pressure control gauge is also installed in the air pipe.

[0009] Furthermore, in step 2, a traction rope is tied to one end of the blocking airbag.

[0010] Furthermore, in the step 2, after the blocking airbag is installed, the water flow in the pipeline is guided to other drainage channels by using the water guiding facilities in the pipeline, and the water guiding facilities are water pipes or temporary drainage channels.

[0011] Furthermore, in the step 2, silt and debris in the pipeline are cleaned using dredging equipment, and the dredging equipment is a sludge suction truck or a high-pressure water gun.

[0012] Furthermore, in the step 2, the inside of the pipeline is inspected by using a detection device to capture ruptures, disconnections, misalignments and minor defects in the pipeline, and the defect locations are accurately recorded. The detection equipment uses a CCTV pipeline detection robot or a sonar detector.

[0013] Furthermore, in the step four, a steel formwork is assembled in the pipeline, wherein the arc-shaped formwork with grouting holes is aligned with the defects of the pipeline so that the reserved exhaust and grouting fullness verification holes are located at the highest point of the grouting space, and the remaining arc-shaped formworks are assembled in the pipeline in turn. Adjacent formworks are fixed with zipper-type connectors, and the connectors include expansion screws and connecting plates with waist-shaped holes.

[0014] In summary, the present invention has the following advantages and beneficial technical effects: 1. The present invention uses a detachable and reusable tool-type steel formwork to save construction costs; the coordination of the limit blocks and the grooves in the steel formwork allows grouting only at cracks, misalignments and disconnections, reducing the impact on the water interface; the grouting material used in the grouting technology is used for structural reinforcement and repair of drainage buildings, has good durability and fluidity, is easy to flow and fill defects, and has a more guaranteed repair quality. The grouting material has a short initial and final setting time, which saves maintenance time, and the steel formwork can be removed as soon as possible to restore underground water and ground traffic; the buffer therein delays the setting time of cement, so that construction personnel have enough time to operate, has a high bonding strength, is well combined with existing pipelines, and the material is not easy to fall off in a complex environment.

[0015] 2. The grouting holes, drainage holes and grouting fullness verification holes reserved in the arc-shaped template of the present invention are convenient for grouting, slurry flow and verification of slurry fullness.

[0016] 3. The ventilation detection in step 2 of the present invention ensures air circulation in the pipeline, reduces the concentration of toxic and harmful gases, and ensures the safety of construction workers; step 3 can effectively deal with defects such as cracks, misalignments, and disconnections, improve the safety and stability of the structure, and at the same time, the application of concrete interface agent can also enhance the bonding force between concretes and improve the overall performance.

[0017] 4. In step 5 of the present invention, the grouting material should be prepared according to the product manual, and the mix ratio should be strictly controlled to ensure the stability of the material performance. The stirring and standing step is to allow the bubbles in the slurry to have a chance to rise to the surface and disappear, thereby improving the quality of the slurry and the grouting effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 It is a usage state diagram of the present invention; Figure 2 It is an axonometric cross-sectional schematic diagram of the arc-shaped template in the present invention; Figure 3 It is a structural schematic diagram of the first arc-shaped template in the present invention; Figure 4 It is a schematic diagram of the structure of the second and third arc-shaped templates in the present invention; Figure 5 It is a structural schematic diagram of the steel template in the present invention; Figure 6 It is a structural schematic diagram of the connecting piece in the present invention.

[0019] The reference numerals in the accompanying drawings are: 1. Steel formwork; 11. Grouting hole; 12. Venting and grouting fullness verification hole; 13. Screw hole; 14. Groove; 15. Limit block; 16. Rubber water stop; 2. Connecting piece; 21. Waist-shaped hole; 3. Drainage pipe. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the implementation of the present invention clearer, the technical solution in the embodiment of the present invention will be described in more detail below in conjunction with the drawings in the embodiment of the present invention. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions; the described embodiments are part of the embodiments of the present invention, not all of the embodiments; the embodiments and directional terms described below with reference to the drawings are exemplary and intended to be used to explain the present invention, and cannot be understood as limitations on the present invention; based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. The embodiments of the present invention are described in detail below in conjunction with the drawings: The following is combined with Figure 1-Figure 6 The present invention is described in further detail: like Figure 1-Figure 4 As shown, this embodiment discloses a trenchless repair method for defects in a large-diameter drainage pipe, comprising the following steps: Step 1: pre-process and manufacture an assembled steel template 1 that is compatible with the inner diameter of the drainage pipe 3, the steel template 1 includes a first arc template, a second arc template and a third arc template that are assembled and fixed in sequence, wherein the first arc template is provided with a grouting hole 11, an exhaust and grouting fullness verification hole 12, and a screw hole 13, and screw holes 13 of the same diameter are provided on both sides of the second and third arc templates. In the cross-sectional view, the center angle of the first arc template is 60°, and the center angles of the second and third arc templates are 150°. Adjacent arc templates are fixed by connecting pieces, and radial grooves 14 are provided on one side of the three arc templates close to the drainage pipe 3, and a rubber water stop 16 is clamped between the steel template 1 and the drainage pipe 3, and two groups of grouting range limit blocks 15 are movably provided in the groove 14; Step 2: A plugging airbag is placed inside the drainage pipe 3, and the upstream section of the pipe defect is plugged with the water-blocking airbag. The plugging airbag is connected to an air pump through an air pipe, and a pressure control meter for monitoring the pressure is also installed on the air pipe. A traction rope is tied to one end of the plugging airbag with an air nozzle. The air pump is turned on to inflate. After the water-blocking airbag expands, it fits tightly against the inner wall of the pipe, thereby achieving temporary sealing inside the pipe. Water diversion in the pipeline. After the plugging airbag is installed, the water diversion facilities in the pipeline are used to guide the water flow in the pipeline to other drainage channels to ensure that subsequent inspection and maintenance work can be carried out without water. The preferred water diversion facilities are: water diversion pipes and temporary drainage channels; Desilting in the pipeline: Use professional desilting equipment to clean the silt and debris in the pipeline to ensure the inner wall of the pipeline is clean and convenient for subsequent inspection work. The preferred desilting equipment is: sludge suction truck, high-pressure water gun; In-pipeline inspection: Use advanced inspection equipment to conduct detailed inspections on the inside of the pipeline, capture cracks, disconnections, misalignments and minor defects in the pipeline, and accurately record the defect locations. The preferred inspection equipment is: CCTV pipeline inspection robot, sonar detector; After the pipeline is cleaned, the construction workers will conduct ventilation inspection, use ventilation equipment to force ventilation on the pipeline, and use gas detectors to detect the air composition in the pipeline to ensure that the air quality meets safety standards. The construction workers will start operations after the conditions for going down the well are met; Step 3: After the construction workers arrive at the exact location of the defect, they will chisel the defect, clean and remove the loose parts and garbage, wash the defect with clean water, dry it and apply the concrete interface agent. The preferred application method is: trowel application, brush application, spray gun application, to ensure that the interface agent evenly covers the defect; like Figure 5-Figure 6 As shown, step 4: positioning, installing and tightening the steel template 1, assembling three arc templates in the drainage pipe 3, aligning the first arc template with the defect of the pipe, making the reserved grouting fullness verification hole located at the highest point of the grouting space, and assembling the remaining two arc templates in the pipe in turn, ensuring that the templates fit tightly and have no gaps, and using zipper-type connectors to sequentially connect and tighten the three arc templates in the drainage pipe 3, so that the steel template 1 is close to the pipe wall, ensuring that the template will not move or fall off during the grouting process, thereby preventing leakage and ensuring the grouting effect. The connectors use connecting pieces 2 and expansion screws, and the connecting piece 2 is provided with a waist-shaped hole 21 matching the expansion screw, and the diameter of the steel template 1 can be appropriately adjusted; Step 5: Connect the grouting pipe and grouting equipment. Before starting grouting, first ensure that the template grouting hole 11, the grouting pipe and the grouting equipment are correctly and firmly connected together, ensure that all channels and joints are kept clean and unblocked, check the operating status of the grouting equipment to ensure that it can work normally and meet the grouting pressure requirements. The preferred grouting equipment is: high-pressure grouting machine; Prepare the slurry according to the manufacturer's mix ratio. The stirring time should be no less than 5 minutes. Keep observing the state of the slurry to ensure that there is no lumps or unmixed parts. After stirring, let it stand for 1-2 minutes. After the bubbles on the surface disappear, perform pressure grouting until the slurry overflows from the exhaust and grouting fullness verification hole 12 for 1 minute to ensure that the repaired part is filled densely. The retarder in the grouting material can delay the setting time of cement. Step 6: The initial setting stage is from the time when water is added to the grouting material until the slurry loses fluidity. The initial setting time should be earlier than 25 minutes. The final setting stage is from the time when water is added to the grouting material until the slurry loses plasticity. The final setting time should be no later than 60 minutes. Wait for the grouting material to finally set for 30 minutes before removing the steel formwork 1 and cleaning the site.

[0021] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the above embodiments, a person skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A trenchless repair method for defects in large-diameter drainage pipes, characterized by: The following steps are involved: Step 1: Prefabricate an assembled steel template that matches the inner diameter of the drainage pipe. The steel template is pre-equipped with grouting holes, exhaust holes, and grouting fullness verification holes; Step 2: Block and guide the drainage pipe, remove silt and inspect the pipe to determine the location and extent of the internal defects. After the pipe is cleaned, the construction personnel will ventilate and inspect it, and start the operation after the conditions for going down the well are met; Step 3: After the construction workers arrive at the exact location of the defect, they will roughen the defect, clean and remove loose parts and garbage, wash the defect with clean water, dry it and apply concrete interface agent; Step 4: Position, install and tighten the steel formwork; Step 5. Connect the grouting pipe and grouting equipment, prepare the slurry according to the manufacturer's mix ratio, and the stirring time should be no less than 5 minutes. After stirring, let it stand for 1-2 minutes. After the bubbles disappear, perform pressure grouting until the grouting fullness verification hole overflows with slurry for 1 minute; Step 6: Remove the steel formwork 30 minutes after the grouting material has finally set and clean up the site.

2. A trenchless repair method for defects in large-diameter drainage pipes according to claim 1, characterized in that: In the step 1, the steel template includes a plurality of groups of arc-shaped templates that are assembled and fixed in sequence, each arc-shaped template is provided with screw holes, and adjacent arc-shaped templates are fixed by connecting pieces.

3. A trenchless repair method for defects in large-diameter drainage pipes according to claim 2, characterized in that: In the step 1, a radial groove is formed on the arc-shaped template near the drainage pipe, and a rubber water stop is sandwiched between the arc-shaped template and the drainage pipe.

4. A trenchless repair method for defects in large-diameter drainage pipes according to claim 3, characterized in that: In the step 1, a plurality of groups of grouting range limit blocks are movably arranged in the groove.

5. A trenchless repair method for defects in large-diameter drainage pipes according to claim 4, characterized in that: In the step 2, a water-blocking airbag is used to block the upstream section of the pipeline defect. The blocking airbag is connected to an air pump through an air pipe, and a pressure control gauge is also installed in the air pipe.

6. A trenchless repair method for defects in large-diameter drainage pipes according to claim 5, characterized in that: In the step 2, a traction rope is tied to one end of the blocking airbag.

7. A trenchless repair method for defects in large-diameter drainage pipes according to claim 6, characterized in that: In the step 2, after the plugging airbag is installed, the water flow in the pipeline is guided to other drainage channels by using the water guiding facilities in the pipeline, and the water guiding facilities are water pipes or temporary drainage channels.

8. A trenchless repair method for defects in large-diameter drainage pipes according to claim 7, characterized in that: In the step 2, silt and debris in the pipeline are cleaned using dredging equipment, and the dredging equipment adopts a sludge suction truck or a high-pressure water gun.

9. A trenchless repair method for defects in large-diameter drainage pipes according to claim 8, characterized in that: In the step 2, the inside of the pipeline is inspected by using a detection device to capture cracks, disconnections, misalignments and minor defects in the pipeline, and the defect locations are accurately recorded. The detection equipment uses a CCTV pipeline detection robot or a sonar detector.

10. A trenchless repair method for defects in large-diameter drainage pipes according to claim 9, characterized in that: In the step 4, a steel formwork is assembled in the pipeline, wherein an arc-shaped formwork with grouting holes is aligned with the defects of the pipeline so that the reserved exhaust and grouting fullness verification holes are located at the highest point of the grouting space, and the remaining arc-shaped formworks are assembled in the pipeline in sequence. Adjacent formworks are fixed with zipper-type connectors, which include expansion screws and connecting plates with waist-shaped holes.

Images