Non-excavation restoration method under sand geologic structure environment

Abstract

The invention discloses a non-excavation repair method under a sand geologic structure environment, which comprises the following steps: S1, pipeline plugging construction: adopting a method of mainly plugging by an inflatable pipe plug and secondarily sealing by a submersible brick, and combining pipeline plugging to carry out self-flow draining or pump draining on pipeline accumulated water; s2, pipeline dredging operation is conducted, specifically, high-pressure water is pumped out through a vehicle-mounted high-pressure pump through a professional special operation vehicle, high-pressure and low-flow-speed water is converted into high-pressure and high-flow-speed jet water through a nozzle, the jet water continuously acts on the inner surface and the interior of a cleaned pipeline, and pipeline cleaning and dredging are achieved; s3, pipeline pretreatment is conducted, specifically, pipeline foreign matter is removed, and a pipeline is pretreated; s4, repairing through a local resin curing method, specifically, a wetted resin fiber material with the functions of water resistance, corrosion resistance and the like is guided into the local damaged part in the pipeline through a hollow air bag, proper air pressure is inflated to enable the repairing air bag to be swelled and then tightly attached to the inner wall of the pipeline, and curing forming is conducted 30 minutes later; and S5, overall repairing.

Description

Technical Field

[0001] The invention belongs to the technical field of pipeline repair, and in particular relates to a trenchless repair method in a sandy geological structure environment. Background Art

[0002] Because the geological structure of some areas such as Hainan is sandy and close to the sea, the rainfall is abundant, and the existing pipelines are basically PE pipes (poor hardness and insufficient bearing capacity), there are no rainwater pipes, only sewage pipes (rainwater and sewage are mixed). Moreover, the PE pipes have been in disrepair for a long time, and many local collapses have occurred, and rainwater will seep into the pipes.

[0003] There are no relevant construction cases in sandy environments, especially in soft geological environments such as sandy areas that are easily affected by rain infiltration and seawater corrosion.

[0004] Before repairing the entire pipeline, it is necessary to repair the partially collapsed part first. Due to the heavy rain and the influence of seawater, during the local repair, rainwater and seawater seep into the sand, and then flow into the pipeline through the damaged opening, causing great damage to the pipeline. Therefore, the existing local repair method requires water operation during the repair. The commonly used resin materials are afraid of water and are not resistant to seawater corrosion, because in the presence of water, conventional resin materials cannot be cured and will be corroded and damaged by seawater.

[0005] If all waterproof and corrosion-resistant resin materials are used for trenchless repairs, the cost will be too high, bringing unbearable cost pressure to the relevant parties and even affecting the local finances. Summary of the invention

[0006] The purpose of the present invention is to solve the above-mentioned problems and provide a method for spot repair using a hollow airbag. The resin material adopts a chloride ion-resistant and waterproof epoxy series, which is corrosion-resistant and quickly solidifies to form a non-excavation repair method in a water-resistant sandy geological structure environment. This method is lower in cost and higher in efficiency than existing operating methods.

[0007] In order to solve the above technical problems, the technical solution of the present invention is: a non-excavation repair method in a sandy geological structure environment, comprising the following steps:

[0008] S1. Pipeline plugging construction: adopt the method of inflatable pipe plugging as the main method and submersible brick plugging as the auxiliary method. Combined with the plugging of the pipeline, the water in the pipeline is drained by gravity or pumped out to drain the water in the target pipeline to ensure the quality and safety of the project;

[0009] S2. Pipeline dredging operation: Through professional special operation vehicles, the on-board high-pressure pump pumps out high-pressure water, and through the nozzle, the high-pressure and low-flow water is converted into high-pressure and high-flow jet water that continuously acts on the inner surface and inside of the cleaned pipeline, so that the scale, silt, sediment, etc. on the pipe wall and inside the pipeline are loosened and fall off, and finally the purpose of pipeline cleaning and dredging is achieved;

[0010] S3, pipeline pretreatment: remove foreign matter from the pipeline and pre-treat the pipeline;

[0011] S4. Local resin curing repair: Use a hollow balloon to introduce fiber materials soaked with resin with waterproof and corrosion-resistant functions into the local damaged part of the pipeline, inject appropriate air pressure to inflate the repair balloon and make it close to the inner wall of the pipeline. After 30 minutes, it will be cured and formed, which can achieve the purpose of local damage, penetration repair and water stop of the pipeline; the resin material adopts chloride ion resistant epoxy series, which can resist seawater and other corrosion and cure quickly, and can be operated under water;

[0012] S5. Overall repair.

[0013] Furthermore, during the pipeline plugging construction in S1, if the upstream water volume of the pipeline is large, a temporary drainage pump and drainage pipe are set in the upstream well to temporarily discharge the upstream water into the adjacent downstream pipeline for water diversion, and a pipe plug is set in the upstream section of the pipeline and a pipe plug is set in the downstream section of the pipeline.

[0014] Furthermore, the professional special operation vehicle in S2 is a high-pressure water jet flushing vehicle, which is moved to a suitable position of the inspection well downstream of the pipeline to be flushed and unblocked. The flushing pressure and flushing speed are selected according to the diameter of the pipeline to be flushed, the pipeline blockage situation, the pipeline material and internal structure, and defects. Under the premise of ensuring that the internal structure of the pipeline is not damaged by high-pressure water, the flushing and unblocking effect is guaranteed to be the best. After the flushing and unblocking is completed, a pipeline CCTV inspection robot is used to inspect and accept the flushing effect.

[0015] Furthermore, the pipeline pretreatment in S3 is to use CCTV detection robot to detect the pipeline after dredging is completed, and then determine the pretreatment method; for areas where the pipeline is severely deformed or damaged, the joints are severely misaligned, and there are severe leaks, the drilling and grouting method is used to reinforce and improve the soil outside the pipeline.

[0016] Furthermore, the detailed steps of the local resin curing method repair in S4 are as follows:

[0017] S401. Block the pipelines with local structural defects and adjust the water supply, then perform high-pressure water jet flushing and dredging on the pipelines;

[0018] S402, perform CCTV inspection robot inspection on the pipeline to determine the location of the damaged pipeline and the size and quantity of the point-like in-situ repair required;

[0019] S403, preparing a fiber cloth;

[0020] S404. Wrap the protective film around and fix it on the airbag, and fix a layer of PE film on the repair airbag to act as an isolation layer to facilitate the subsequent separation of the airbag and the material. Since there is a lot of rain in the area and the old pipes are damaged in many places, a hollow airbag is selected. The specifications of the hollow airbag must meet the size requirements of the pipe to be repaired. The middle of the hollow airbag is empty, and rainwater can flow through the middle of the airbag.

[0021] S405, determine the amount of resin, and pour the resin and curing agent into a container. Since there is a lot of rain and it is close to the sea, a waterproof and corrosion-resistant resin material is selected;

[0022] S406, mixing the resin and the curing agent, pouring the resin onto the surface of the glass fiber with oriented fibers, and evenly applying the resin with a hand scraper for impregnation;

[0023] S407, fold the impregnated glass fiber by 1 / 3 and apply the resin on the surface; fold the fiber layer again, apply the resin evenly on the top fiber layer, and apply it evenly with a spatula; turn over the fiber cloth, apply the resin on the fiber layer, and apply it evenly with a spatula;

[0024] S408. Fix the glass fiber impregnated with resin on the surface of the airbag. The fiber cloth impregnated with resin should be placed on the repair airbag and prevented from slipping. During the construction, the repair airbag is used to ensure that when the airbag reaches the area to be repaired, the fiber cloth impregnated with resin does not touch the inner wall of the pipe, and there must be overlap between the fibers.

[0025] S409, secure the fiber mat in place with binding wire;

[0026] S410, after placing the airbag in the pipeline, connect the hose on the air compressor to the airbag, and then push or pull the airbag into the pipeline and locate it at the part to be repaired;

[0027] S411, inflate the airbag to make the material fit with the original pipe; apply pressure according to the requirements of compressed air to expand the airbag, so that the fiber and the original pipe fit closely; maintain pressure until the resin is completely cured, squeeze out excess resin at both ends of the repair area to form a tapered transition area with the original pipe that is conducive to water conservancy traffic;

[0028] S412. After the final curing is completed, the air is released and the airbag is removed.

[0029] Furthermore, during the resin curing in S411, the airbag pressure should be maintained at 1.5 Bar, the felt tube should be kept close to the tube wall, and the curing time of the room temperature curing resin should be 2h to 4h, and should not be less than 1h.

[0030] Furthermore, the overall repair in S5 includes the principle of UV curing repair: the lining hose of the fiber-reinforced resin-based material is pulled into the pre-treated pipe, the lining hose and the original pipe are kept in close contact by inflating and pressurizing with a blower, and the resin is cured by UV heating using the photosensitive characteristics to form a new high-strength lining resin pipe.

[0031] Furthermore, the specific method of the overall repair in S5 including UV curing repair is:

[0032] S51, pull in the protective cushion film;

[0033] S52, pull in the fiber lined hose;

[0034] S53, hose inflation and pressurization and UV lamp installation;

[0035] S54, UV curing;

[0036] S55, end treatment;

[0037] S56, extract the inner membrane of the hose;

[0038] S57. Inspection and acceptance.

[0039] Furthermore, during the UV curing in S54, the temperature should be raised evenly, and the time, temperature and temperature rise rate required for curing should refer to the regulations of the resin material and be appropriately adjusted according to the specific construction conditions on site. The curing construction should not be carried out at an air temperature greater than 30°C or less than -5°C; during curing, the speed of the UV lamp should be controlled according to the pipe diameter and wall thickness, and should not be greater than 1m / min.

[0040] Furthermore, during the inspection and acceptance in S57, the wall thickness and mechanical properties of the liner pipe after curing shall comply with the current national standards and the relevant provisions and design requirements of this guideline; the wall thickness shall not be less than the design value, and the average wall thickness shall not be greater than 20% of the design wall thickness; according to the wall thickness calculation formula, the wall thickness of the liner pipe is inversely proportional to the long-term elastic modulus of the material. As the material properties are enhanced, the wall thickness can be reduced within the specified range.

[0041] The beneficial effects of the present invention are:

[0042] 1. The present invention provides a trenchless repair method in a sandy geological structure environment. (1) A hollow airbag is used for spot repair. The hollow airbag is hollow in the middle, and rainwater can flow through the middle of the airbag. (2) The resin material adopts a chloride ion-resistant and waterproof epoxy series, which is resistant to seawater and corrosion and quickly solidifies, and can be operated in water.

[0043] 2. The present invention can be used in areas where water is required to be brought in, because there is a lot of rain in the area and the influence of seawater, it rains from time to time during the day, and infiltrates from special geological conditions such as sandy land, and geology with a lot of rain. The waterproof and anti-corrosion resin is used, and it can be cured quickly.

[0044] 3. The present invention uses a hollow airbag, which is hollow in the middle compared to the traditional airbag, and can divert rainwater. However, there is a lot of rain in this area. If one end of the pipe is blocked, rainwater will infiltrate the pipe from the sand through the collapsed holes and other defects of the PE pipe, so rainwater will still flow. The present invention uses an airbag with a hollow middle, and the running water can flow away from the middle of the airbag. It can solve related problems.

[0045] 4. The present invention solves the problem of trenchless repair of pipelines affected by rainwater and seawater corrosion in sandy environments such as Hainan. At the same time, it also solves the problem of high cost of trenchless repair of large areas using waterproof and corrosion-resistant resins and other materials. Compared with existing repair methods, the cost is lower and the efficiency is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a schematic diagram of the steps of a trenchless repair method in a sandy geological structure environment of the present invention;

[0047] Figure 2 This is a schematic diagram of water plugging and water regulation of the present invention;

[0048] Figure 3 This is a schematic diagram of main pipe plugging of the present invention;

[0049] Figure 4 It is a schematic diagram of the pipe (intersection pipe) plugging of the present invention;

[0050] Figure 5 This is a comparison diagram of the repair effect of the point-shaped in-situ curing method of the present invention; DETAILED DESCRIPTION

[0051] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments:

[0052] like Figures 1 to 5 As shown, the present invention provides a trenchless repair method in a sandy geological structure environment, comprising the following steps:

[0053] S1. Pipeline plugging construction: adopt the method of inflatable pipe plugging as the main method and submersible brick plugging as the auxiliary method. Combined with the pipeline plugging, the water in the pipeline is drained by gravity or pumped out to drain the water in the target pipeline to ensure the quality and safety of the project.

[0054] According to the diameter range of the drainage pipes in the project and combined with Table 1, it can be concluded that the blocking methods for the drainage pipes within the construction scope of this project can be selected: inflatable pipe plugs (blocking air bags) and wall blocking.

[0055]

[0056] Table 1 Pipeline plugging methods

[0057] The plugging construction of the present invention adopts a method of mainly plugging with an inflatable pipe plug and supplemented by a submersible brick plugging method. Combined with the plugging of the pipeline, the accumulated water in the pipeline is drained by gravity or pumped out, so that the water in the target pipeline is drained to ensure the quality and safety of the project.

[0058] In step S1, when the pipeline is plugged, if the upstream water volume of the pipeline is large, a temporary drainage pump and drainage pipe are set in the upstream well to temporarily discharge the upstream water into the adjacent downstream pipeline for water diversion. A pipe plug is set in the upstream section of the pipeline and a pipe plug is set in the downstream section of the pipeline. Figure 2 shown.

[0059] According to the actual situation, the present invention adopts a method of blocking one place every 200m for the sewage pipe network. The pipeline to be constructed is well No. 1 to well No. 4, and after the construction of the pipeline from well No. 1 to well No. 4 is completed, the construction of well No. 4 to well No. 7 is carried out. At this time, the plug of well No. 4 needs to be removed and re-blocked in the opposite direction, that is, each pipe section to be constructed needs to be blocked at least two places, such as Figure 3 As shown, in special environments, such as sandy areas in Hainan, due to the unstable geology, the slope of some pipelines is not obvious or there is no slope, which will cause water to flow back in some pipelines. In order to solve this problem, the method of blocking both ends is adopted.

[0060] Through the arrangement of the present invention, water flows from high to low. Generally, a plug is added upstream of the pipeline under construction, and rainwater in the pipeline automatically flows away, thereby eliminating the need to plug the downstream.

[0061] During construction, all pipes that connect water flow to the main pipe need to be blocked. If a three-way well or a cross intersection well is encountered, in order to ensure the integrity of the construction pipeline, all other branch pipes that intersect need to be blocked, such as Figure 4 shown.

[0062] The inflatable pipe plug of the present invention must be used when plugging. The water pressure on the pipe plug must not be greater than the maximum allowable pressure of the plug. The location where the pipe plug is placed must not have stones or other debris. The pipe plug should be inflated according to the specified pressure. During use, a dedicated person must check the air pressure every day. If it is found to be lower than the specified pressure, it must be replenished in time. Anti-slip support measures should be provided. When deflation, underground operators must not stay in the well.

[0063] When the wall of the present invention blocks a pipeline, the safe thickness of the wall is selected according to the water pressure and the pipe diameter, and additional support should be provided if necessary. When blocking a flowing water pipeline, it is advisable to pre-embed one or more small-diameter short pipes in the wall to maintain the flowing water. When the wall reaches the service strength, the reserved holes are blocked. When dismantling the wall, the pipe plug in the pre-embedded short pipe should be removed first, and the upstream water level should be lowered. During the drainage process, personnel should not stay in the well, and the dismantling can only start after the water flow is normal. The wall must be completely dismantled and cleaned.

[0064] S2. Pipeline dredging operation: Through professional special operation vehicles, the on-board high-pressure pump pumps out high-pressure water, and through the nozzle, the high-pressure and low-flow water is converted into high-pressure and high-flow jet water, which continuously acts on the inner surface and inside of the cleaned pipeline, thereby loosening and falling off the scale, silt, sediment, etc. on the pipe wall and inside the pipeline, and finally achieving the purpose of pipeline cleaning and dredging.

[0065] In step S2, the professional special operation vehicle is a high-pressure water jet flushing vehicle, which is moved to a suitable position of the downstream inspection well of the pipeline to be flushed and unblocked. The flushing pressure and flushing speed are selected according to the diameter of the pipeline to be flushed, the pipeline blockage, the pipeline material and internal structure, and defects. Under the premise of ensuring that the internal structure of the pipeline is not damaged by high-pressure water, the flushing and unblocking effect is guaranteed to be the best. After the flushing and unblocking is completed, a pipeline CCTV inspection robot is used to inspect and accept the flushing effect.

[0066] For large and extra-large rainwater and sewage pipes, when there is serious accumulation and siltation inside the pipes, and silt or impurities are seriously precipitated and compacted, and the high-pressure water jet flushing effect is not good, professional construction workers will enter the inspection wells and rainwater and sewage pipes to carry out manual excavation and cleaning, under the premise of ensuring safety and taking various safety technical measures and guarantee measures.

[0067] During manual excavation, the relevant regulations must be strictly followed. Manual excavation workers must obtain a "limited space operation certificate" or be trained and pass the examination by a unit with relevant training qualifications, and obtain a skill training certificate for workers in the well and pool. Manual excavation of drainage pipes should be carried out from the bottom to the top from the downstream inspection well. If necessary, retaining walls should be set up in the pipe to separate the operation section. After the operation is completed, the workers should evacuate in time.

[0068] In addition to complying with the above regulations, manual excavation shall also comply with the following regulations: A sturdy working tripod or operating platform shall be set up in the downstream inspection well of the excavated pipeline section, and the sludge shall be lifted mechanically, and the lifting equipment shall be firmly fixed at the upper end of the inspection well. Operators shall be well prepared and wear safety protection equipment before entering the pipeline, and the tools and equipment used shall be lowered to the bottom of the well in a safe and orderly manner. Dredging shall be carried out from the downstream of the well section to the upper well section by section, and the sludge shall be loaded into sludge barrels or mud trucks.

[0069] The mud transporters in the trench transport the sludge to the mud loading area or the inspection well chamber (if it is thin mud, the mud can be pushed to the wellhead with a scraper). After each well section is excavated, the well cover of the operating well section should be covered immediately. Manual excavation should be carried out together with the cleaning of the inspection well, and the sludge and sediment should be cleaned out of the pipeline and inspection well and stored and disposed of in accordance with the regulations.

[0070] S3. Pipeline pretreatment: remove foreign matter from the pipeline and pretreat the pipeline.

[0071] When clearing foreign objects in the pipes, including foreign objects in the pipes, tree roots, concrete consolidations, and obstacles, a milling cutter robot is used to remove tree roots, cement blocks, exposed steel meshes, concrete consolidations, obstacles, etc. in the drainage pipes.

[0072] In step S3, after the pipeline pretreatment is completed, CCTV detection robots are required to perform pipeline inspection and then determine the pretreatment method. For pipelines with serious deformation or damage, serious joint misalignment, and serious water leakage, drilling and grouting methods are used to reinforce and improve the soil outside the pipeline. For existing pipelines with serious water leakage, water stopping or water isolation treatment should be carried out on the leaking points.

[0073] After the pretreatment is completed, CCTV inspection and review are conducted again to ensure that the lining construction can be carried out in the pipeline. CCTV conducts an internal inspection of the pipeline and implements pretreatment based on the inspection results. There should be no sediment, garbage or other obstacles in the original pipeline after pretreatment, and there should be no water accumulation that affects the construction. When non-excavation overall or partial repair is adopted, there should be no water seepage in the original pipeline. The inner surface of the pipeline should be clean, and there should be no attachments, sharp burrs or protrusions that affect the lining. Obstacles in the pipeline that affect the lining construction should be removed by special tools or local excavation. If there is a local leakage in the pipeline, the local disease point should be repaired with a stainless steel sleeve ring at the serious leakage point. The general leakage point should be repaired with local resin curing at the local disease point. After the local disease treatment is completed, the pipeline should be repaired as a whole. Pipeline grouting reinforcement requirements: When it is found that there is a rupture, leakage or obvious subsidence in the road inside the pipeline, and there is a loss of soil outside the pipeline, grouting construction should be carried out around the outside of the pipeline. The grouting hole spacing is 1 meter, with the inner row of holes 0.5 meters outside the pipe wall as the axis, the outer row of holes is 1 meter away from the inner row of holes, and the holes are arranged in a herringbone shape in the plane.

[0074] Requirements for repair materials used in the grouting method: The grouting slurry should be able to react quickly in groundwater, gel and not degrade in water, not react with organic matter in water, and not biodegrade. The purpose of increasing the slurry mixing viscosity, density, and coagulation strength can be achieved by adding additives or increasing the solution concentration. The grouting slurry must be uniform and prevent leakage from defects. The processing, mixing, and transportation links must meet the requirements of the chemical slurry ratio, and the chemical slurry must be transported to the construction site in a closed, unopened container. By adjusting the gel time of the chemical slurry, it is suitable for different soil conditions. The residual chemical slurry in the pipeline must be easy to remove to avoid obstructing the passage of sewage, and the inner wall of the pipeline must be smooth and leak-free.

[0075] S4. Local resin curing repair: Use a hollow balloon to introduce fiber materials soaked with resin with functions such as waterproof and corrosion-resistant into the local damaged part of the pipeline. Then inject appropriate air pressure to expand the repair balloon and make it close to the inner wall of the pipeline. After 30 minutes, it will solidify into shape, thus achieving the purpose of local damage, penetration repair and water stopping of the pipeline.

[0076] The detailed steps of the local resin curing method repair in step S4 are as follows:

[0077] S401. Seal and adjust water supply for pipelines with local structural defects, and then use high-pressure water jets to flush, desilt and dredge the pipelines.

[0078] S402: Use a CCTV inspection robot to inspect the pipeline to determine the location of the damaged pipeline and the size and quantity of the damaged pipeline that needs to be repaired in situ.

[0079] S403, prepare fiber cloth.

[0080] S404. Wrap the protective film around the airbag and fix it. Fix a layer of PE film on the repair airbag to act as an isolation layer to facilitate the subsequent separation of the airbag and the material. Since there is a lot of rain in the area and the old pipes are damaged in many places, a hollow airbag is selected. The specifications of the hollow airbag must meet the size requirements of the pipe to be repaired. The middle of the hollow airbag is empty, and rainwater can flow through the middle of the airbag.

[0081] In actual use, the hollow balloon is an elastomer, and the balloon specifications are DN200-DN500, which can repair DN200-DN500 pipes.

[0082] S405, determine the amount of resin used, and pour the resin and curing agent into a container. Due to the heavy rain and proximity to the sea, a waterproof and corrosion-resistant resin material is selected.

[0083] S406, mixing the resin and the curing agent, pouring the resin onto the surface of the glass fiber with oriented fibers, and evenly applying the resin with a hand scraper for impregnation.

[0084] S407, fold the impregnated glass fiber by 1 / 3 and apply the resin on the surface; fold the fiber layer again, apply the resin evenly on the top fiber layer, and apply it evenly with a spatula; turn over the fiber cloth, apply the resin on the fiber layer, and apply it evenly with a spatula.

[0085] S408. Fix the glass fiber impregnated with resin on the surface of the airbag. The fiber cloth impregnated with resin should be placed on the repair airbag and prevented from slipping. During construction, the repair airbag is used to ensure that the fiber cloth impregnated with resin does not touch the inner wall of the pipe when the airbag reaches the area to be repaired. There must be overlap between the fibers. The resin material adopts the epoxy series that is resistant to chloride ions, can resist seawater and other corrosion, and cures quickly, and can be operated in water.

[0086] S409, secure the fiber mat in place with binding wire.

[0087] S410, after placing the airbag in the pipeline, connect the hose on the air compressor to the airbag, and then push or pull the airbag into the pipeline and locate it at the part to be repaired.

[0088] S411. Inflate the airbag to make the material fit the original pipe; apply pressure according to the requirements of compressed air to make the airbag expand and swell, so that the fiber and the original pipe fit tightly; maintain pressure until the resin is cured, squeeze out excess resin at both ends of the repair area to form a conical transition area with the original pipe that is conducive to water passage.

[0089] In step S411, the airbag pressure should be maintained at 1.5 Bar during the resin curing period, and the felt tube should be kept close to the tube wall. The curing time of the room temperature curing resin should be 2h to 4h, and should not be less than 1h.

[0090] S412. After the final curing is completed, the air is released and the airbag is removed.

[0091] The curing method of the present invention mainly includes two technologies: artificial fiberglass joint and felt tube airbag local molding. The resin is cured at the damaged point to increase the strength of the pipeline to achieve the purpose of repair and provide a certain structural strength. It is also called point-shaped in-situ curing method. Its repair effect is comparable to Figure 5 As shown, in Figure 5 (a) shows the effect before the point-shaped in-situ solidification method repair, and (b) shows the effect after the point-shaped in-situ solidification method repair. In the trenchless repair of drainage pipes, it is usually used in conjunction with soil grouting technology. Protect the environment and save resources. No excavation of the road surface, no garbage, no traffic congestion, greatly improve the image of pipeline repair construction. The overall social and economic benefits are good.

[0092] During the construction of the curing method of the present invention: the damaged part of the pipe must be cleaned, the felt tube should be pre-coated with resin under vacuum conditions, and the felt tube must be fastened to the airbag with iron wire to prevent the felt tube from falling off when the airbag enters the pipeline. Inflation and deflation should be slow and uniform. During the resin curing period, the airbag pressure should be maintained at 1.5 Bar, and the felt tube should be kept close to the pipe wall. The curing time of the room temperature curing resin is preferably 2h to 4h, and shall not be less than 1h. If ultraviolet light curing is used, the process requirements shall be implemented according to the overall requirements of ultraviolet light curing.

[0093] S5. Overall repair.

[0094] The principle of the overall repair including UV curing repair in step S5 is: pull the lining hose of the fiber-reinforced resin-based material into the pre-treated pipe, inflate and pressurize it with a blower to keep the lining hose and the original pipe in close contact, and use the photosensitive characteristics of the resin to perform ultraviolet heating and curing to form a new high-strength lining resin pipe.

[0095] The specific method of overall repair including UV curing repair in step S5 is:

[0096] S51. Pull in the protective cushion film.

[0097] The protective cushion film protects the lining hose and prevents it from being scratched and damaged by protrusions during the pulling process. The protective cushion film should be placed at the bottom of the original pipeline and should cover more than 1 / 3 of the pipeline circumference, and should be firmly fixed at both ends of the original pipeline.

[0098] S52, pull in the fiber-lined hose.

[0099] Place the sliding roller in the appropriate position, then pull the rolled and pre-cut fiber hose from the inspection well into the pipe to be repaired, and install airtight ties at both ends of the pipe.

[0100] S53, hose inflation and pressurization and UV lamp installation.

[0101] Connect the air supply pipe between the compressor and the hose, inflate the liner hose, and expand the liner hose by air pressure. Pull the UV lamp car into the hose (after inflation) through the pipe tie head.

[0102] S54, UV curing.

[0103] By setting the control parameters of the ultraviolet lamp trolley's crawling speed and the temperature inside the hose, and combining with the CCTV monitoring on the trolley, the control parameters are adjusted in time to make the hose resin in the set hardening condition, turn on the ultraviolet lamp, and the fiber lining tube will solidify and cover the inner wall of the old pipe where the ultraviolet lamp passes.

[0104] During UV curing in step S54, the temperature should be raised evenly. The time, temperature and temperature rise rate required for curing should refer to the regulations of the resin material and be appropriately adjusted according to the specific construction conditions on site. Curing construction should not be carried out at an air temperature greater than 30°C or less than -5°C. During curing, the speed of the UV lamp should be controlled according to the pipe diameter and wall thickness, and should not be greater than 1m / min.

[0105] During the curing process, the air pressure in the hose should be able to ensure close contact between the hose and the original tube, and maintain this pressure value until the curing is completed. After the curing is completed, the air pressure in the tube should be slowly reduced to atmospheric pressure.

[0106] The performance, specifications and dimensions of engineering materials such as hoses and resins shall comply with relevant regulations and design requirements, the quality assurance information shall be complete, and the transportation and storage of resins shall meet the requirements. A full inspection shall be carried out during acceptance, including the on-site acceptance records, quality assurance information, manufacturer's product instructions, etc.; and the transportation and storage records of resins shall be checked.

[0107] After curing, the wall thickness and mechanical properties of the liner pipe shall comply with the current national standards and the relevant provisions and design requirements of this guideline. The wall thickness shall not be less than the design value, and the average wall thickness shall not be greater than 20% of the design wall thickness. According to the wall thickness calculation formula, the wall thickness of the liner pipe is inversely proportional to the long-term elastic modulus of the material. As the material performance increases, the wall thickness can be reduced within the specified range. During inspection, the design documents should be compared and tested in accordance with relevant regulations; the test report and test records of the sample pipe or sample plate should be checked; the wall thickness of the liner pipe should be measured on site with a thickness gauge, caliper, etc.

[0108] S55, end processing.

[0109] After solidification, cut off the outer and inner lining pipes of the old pipe, remove the tying head, ventilation pipe, and trolley, and trim the burrs at both ends after cutting.

[0110] S56. Pull out the inner membrane of the hose.

[0111] After the end is processed, remove the inner membrane of the hose and clean up the curing operation site.

[0112] S57. Inspection and acceptance.

[0113] Use pipeline CCTV detection system to detect the inside of the repaired pipeline and record the inner wall inspection video data of the inner lining pipe. The inner lining pipe wall should be smooth and continuous without damage or leakage.

[0114] During the inspection and acceptance in step S57, the wall thickness and mechanical properties of the liner pipe after curing shall comply with the current national standards and the relevant provisions and design requirements of this guideline; the wall thickness shall not be less than the design value, and the average wall thickness shall not be greater than 20% of the design wall thickness; according to the wall thickness calculation formula, the wall thickness of the liner pipe is inversely proportional to the long-term elastic modulus of the material. As the material properties are enhanced, the wall thickness can be reduced within the specified range.

[0115] During the inspection, the on-site thickness measurement requirements are as follows: When the inner diameter of the pipe is greater than 800mm, it should be measured inside the pipeline, with each 5m as a section, and 4 points in the vertical direction of each section are measured, and the average value is taken as the representative value (average wall thickness) of the section; if the original pipeline is corroded, scaled, etc., the original inner diameter of the pipeline should be measured during construction. When the inner diameter of the pipe is less than or equal to 800mm, measure a section at each end of the pipeline, measure 4 points in the vertical direction of each section, sample at 45°, 135°, 225° and 315°, and then take the average value as the representative value (average wall thickness) of the section.

[0116] The new inner lining pipe requires two groups of test blocks to be sampled from the pipe sections between adjacent inspection wells for inspection. After the repair, the pipeline is linear and smooth, the transition at the bend or misalignment is smooth, and the circular section arc is full. The inspection is completed by full observation (CCTV auxiliary inspection), inspection of construction records, CCTV records, etc. The sealing treatment of the starting and ending ends of the inner lining pipe meets the design requirements, and the seal is good, full and dense. Full observation during inspection; check the construction records against the design documents, etc. The inspection wells and wells of the repaired pipeline meet the design requirements and there is no water leakage. Full observation during inspection, check the construction records against the design documents, etc. The repair construction records are complete and correct, and the record content should include data such as the length of the hose pulled in, the expanded compressed air pressure, the hose curing temperature, time and pressure, the cruising speed of the ultraviolet lamp, and the cooling time and pressure of the inner lining pipe. Check the design documents and construction plan according to the relevant provisions of this guideline, and check the construction records, etc. The stability, operational safety and service life of the hose lining shall not be affected by wrinkles.

[0117] The repair objective is to achieve a wrinkle-free hose lining. Depending on the special conditions of the pipeline operating conditions, such as deformation, cross-sectional changes, pipeline misalignment, etc., wrinkles may be formed, and the following limits apply: within the straight section and the curved section with a turning radius R > 10d, the wrinkles shall not exceed 2% of the rated diameter or 6 mm; when it is a curved section with a turning radius of 5d < R < 10d, the maximum wrinkle depth is 3% of the d value or 2 cm.

[0118] The acceptance of the ultraviolet light cured pipeline shall conduct tightness and density tests in strict accordance with the specific provisions of the corresponding chapters in the "Technical Specification for the Trenchless Repair and Renewal of Urban Drainage Pipelines". Among them, the tightness test can choose to adopt the airtightness test or the water tightness test according to the specific on-site operating conditions. The water head for the water tightness test shall meet the requirements of the "Code for Construction and Acceptance of Water Supply and Drainage Pipelines", and the observation time of the seepage volume shall not be less than 30 minutes.

[0119] During the use of the present invention, records and inspections shall be made on the hose pulling-in length, expansion compressed air pressure, curing temperature, time and pressure, and ultraviolet cruising speed, as well as the lining pipe cooling temperature, time, and pressure of the overall lining repair construction.

[0120] After the repair by the ultraviolet light in-situ curing method, the cut end of the cured pipe shall be flat, the cut shall be flush with the well wall, and the sealing shall be free of water seepage.

[0121] The wall thickness of the repaired lining pipe shall meet the design and specification requirements.

[0122] The repaired lining pipe shall be inspected by CCTV detection equipment and shall meet the following requirements: there shall be no leakage inside the repaired lining pipe. The internal defects of the pipeline repaired by local repair shall be completely covered by the repair material, and the repair material shall be able to fit tightly with the original pipeline. The repaired lining pipe shall not have defects affecting the pipeline use function such as local depression, scratch, crack, wear, hole, bubble, dry spot, bulge, delamination, and weak zone.

[0123] During the acceptance inspection, provide the video of the pipeline inspection before construction and the video of the pipeline inspection after construction. After the construction is completed, organize and archive the relevant information. After the lining material is solidified, it is sampled on site under the witness of the supervisor and sent to a qualified third-party testing agency for testing. The test content is the three parameters of elastic modulus, bending strength and tensile strength required in the design documents. The results should comply with the provisions of "Technical Code for Trenchless Repair and Renewal of Urban Drainage Pipelines" CJJ / 210-2014. During the quality warranty period, in accordance with relevant legal provisions and contractual agreements, assume the responsibility for engineering quality warranty. Water-tightening test: ① The appearance quality of the pipeline and inspection well has been accepted. ② The length of the water-tightening test pipe section shall not exceed 500m. ③ The water-tightening test shall be carried out in accordance with the requirements of Article 10.3 of GB50268-2008. ④ The water-tightening test results shall meet the requirements of GB50268-2008.

[0124] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed by the present invention, and these variations and combinations are still within the protection scope of the present invention.

Claims

1. A trenchless repair method in a sandy geological structure environment, characterized in that: The following steps are involved: S1. Pipeline plugging construction: adopt the method of inflatable pipe plugging as the main method and submersible brick plugging as the auxiliary method. Combined with the plugging of the pipeline, the water in the pipeline is drained by gravity or pumped out to drain the water in the target pipeline to ensure the quality and safety of the project; S2. Pipeline dredging operation: Through professional special operation vehicles, the on-board high-pressure pump pumps out high-pressure water, and through the nozzle, the high-pressure and low-flow water is converted into high-pressure and high-flow jet water that continuously acts on the inner surface and inside of the cleaned pipeline, so that the scale, silt, sediment, etc. on the pipe wall and inside the pipeline are loosened and fall off, and finally the purpose of pipeline cleaning and dredging is achieved; S3, pipeline pretreatment: remove foreign matter from the pipeline and pre-treat the pipeline; S4. Local resin curing repair: Use a hollow balloon to introduce fiber materials soaked with resin with waterproof and corrosion-resistant functions into the local damaged part of the pipeline. Fill it with appropriate air pressure to expand the repair balloon and make it close to the inner wall of the pipeline. After 30 minutes, it will be cured and formed, which can achieve the purpose of local damage, penetration repair and water stop of the pipeline; the resin material adopts the chloride ion resistant epoxy series, which is resistant to seawater and other corrosion and cures quickly, and can be operated under water; S5. Overall repair.

2. The trenchless repair method in a sandy geological structure environment according to claim 1, characterized in that: During the pipeline plugging construction in S1, if the upstream water volume of the pipeline is large, a temporary drainage pump and drainage pipe are set in the upstream well to temporarily discharge the upstream water into the adjacent downstream pipeline for water adjustment, and a pipe plug is set in the upstream section of the pipeline and a pipe plug is set in the downstream section of the pipeline.

3. The trenchless repair method in a sandy geological structure environment according to claim 1, characterized in that: The professional special operation vehicle in S2 is a high-pressure water jet flushing vehicle. The high-pressure water jet flushing vehicle is moved to a suitable position in the downstream inspection well of the pipeline to be flushed and unblocked. The flushing pressure and flushing speed are selected according to the diameter of the pipeline to be flushed, the pipeline blockage situation, the pipeline material and internal structure, and defects. Under the premise of ensuring that the internal structure of the pipeline is not damaged by high-pressure water, the flushing and unblocking effect is guaranteed to be the best. After the flushing and unblocking is completed, a pipeline CCTV inspection robot is used to inspect and accept the flushing effect.

4. The trenchless repair method in a sandy geological structure environment according to claim 1, characterized in that: The pipeline pretreatment in S3 is to use CCTV detection robot to detect the pipeline after dredging is completed, and then determine the pretreatment method; for areas where the pipeline is severely deformed or damaged, the joints are severely misaligned, and there are severe leaks, the drilling and grouting method is used to reinforce and improve the soil outside the pipeline.

5. The trenchless repair method in a sandy geological structure environment according to claim 1, characterized in that: The detailed steps of the local resin curing repair method in S4 are as follows: S401. Block the pipelines with local structural defects and adjust the water supply, then perform high-pressure water jet flushing and dredging on the pipelines; S402, perform CCTV inspection robot inspection on the pipeline to determine the location of the damaged pipeline and the size and quantity of the point-like in-situ repair required; S403, preparing a fiber cloth; S404. Wrap the protective film around and fix it on the airbag, and fix a layer of PE film on the repair airbag to act as an isolation layer to facilitate the subsequent separation of the airbag and the material. Since there is a lot of rain in the area and the old pipes are damaged in many places, a hollow airbag is selected. The specifications of the hollow airbag must meet the size requirements of the pipe to be repaired. The middle of the hollow airbag is empty, and rainwater can flow through the middle of the airbag. S405, determine the amount of resin, and pour the resin and curing agent into a container. Since there is a lot of rain and it is close to the sea, a waterproof and corrosion-resistant resin material is selected; S406, mixing the resin and the curing agent, pouring the resin onto the surface of the glass fiber with oriented fibers, and evenly applying the resin with a hand scraper for impregnation; S407, fold the impregnated glass fiber by 1 / 3 and apply the resin on the surface; fold the fiber layer again, apply the resin evenly on the top fiber layer, and apply it evenly with a spatula; turn over the fiber cloth, apply the resin on the fiber layer, and apply it evenly with a spatula; S408. Fix the glass fiber impregnated with resin on the surface of the airbag. The fiber cloth impregnated with resin should be placed on the repair airbag and prevented from slipping. During the construction, the repair airbag is used to ensure that when the airbag reaches the area to be repaired, the fiber cloth impregnated with resin does not touch the inner wall of the pipe, and there must be overlap between the fibers. S409, secure the fiber mat in place with binding wire; S410, after placing the airbag in the pipeline, connecting the hose on the air compressor to the airbag, and then pushing or pulling the airbag into the pipeline and positioning it at the position to be repaired; S411, inflate the airbag to make the material fit with the original pipe; apply pressure according to the requirements of compressed air to expand the airbag, so that the fiber and the original pipe fit closely; maintain pressure until the resin is completely cured, squeeze out excess resin at both ends of the repair area to form a tapered transition area with the original pipe that is conducive to water conservancy traffic; S412. After the final curing is completed, the air is released and the airbag is removed.

6. The trenchless repair method in a sandy geological structure environment according to claim 1, characterized in that: During the curing of the resin in S411, the airbag pressure should be maintained at 1.5 Bar, and the felt tube should be kept close to the tube wall. The curing time of the room temperature curing resin should be 2h to 4h, and should not be less than 1h.

7. The trenchless repair method in a sandy geological structure environment according to claim 1, characterized in that: The principle of the overall repair in S5 including UV curing repair is: pull the lining hose of the fiber-reinforced resin-based material into the pre-treated pipeline, inflate and pressurize it with a blower to keep the lining hose and the original pipeline in close contact, and use the photosensitivity of the resin to perform UV heating and curing to form a new high-strength lining resin pipe.

8. The trenchless repair method in a sandy geological structure environment according to claim 1, characterized in that: The specific method of the overall repair in S5 including UV curing repair is: S51, pull in the protective cushion film; S52, pull in the fiber lined hose; S53, hose inflation and pressurization and UV lamp installation; S54, UV curing; S55, end treatment; S56, extract the inner membrane of the hose; S57. Inspection and acceptance.

9. The trenchless repair method in a sandy geological structure environment according to claim 1, characterized in that: During UV curing in S54, the temperature should be raised evenly. The time, temperature and temperature rise rate required for curing should refer to the regulations of the resin material and be appropriately adjusted according to the specific construction conditions on site. Curing construction should not be carried out at an air temperature greater than 30°C or less than -5°C. During curing, the speed of the UV lamp should be controlled according to the pipe diameter and wall thickness, and should not be greater than 1m / min.

10. The trenchless repair method in a sandy geological structure environment according to claim 1, characterized in that: During the inspection and acceptance in S57, the wall thickness and mechanical properties of the cured liner pipe shall comply with the current national standards and the relevant provisions and design requirements of this guideline; the wall thickness shall not be less than the design value, and the average wall thickness shall not be greater than 20% of the design wall thickness; According to the wall thickness calculation formula, the wall thickness of the liner pipe is inversely proportional to the long-term elastic modulus of the material. As the material performance is enhanced, the wall thickness can be reduced within the specified range.

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