Whole-process construction method for water supply and drainage pipeline of complex stratum in coastal area

Abstract

The invention relates to the technical field of water supply and drainage pipeline construction, in particular to a coastal area complex stratum water supply and drainage pipeline whole-process construction method. During construction, firstly, personnel, materials and equipment are prepared, surveying and setting-out are conducted, and trench excavation is completed; model selection is carried out by comprehensively considering the strength, weight and corrosion resistance of the pipe; hill-skill stones and graded broken stones are adopted to treat the foundation, and the stability of the pipe foundation is guaranteed; the pipeline is subjected to multiple times of anti-corrosion treatment, so that the corrosion resistance is improved; when the inspection well is constructed, the corrosion inhibitor is added to improve the performance; glass fiber geogrids are encapsulated and laid on the branch pipes; and finally, medium-coarse sand is used for backfilling and acceptance. According to the method, the pipe base bearing capacity is enhanced, the service life of the pipeline is prolonged, the later maintenance cost is reduced, pavement excavation is reduced, the construction period is shortened, and the engineering cost is saved through the technologies of pipe base treatment, pipe optimization, corrosion prevention and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of water supply and drainage pipeline construction, and specifically to a whole-process construction method for water supply and drainage pipelines in complex strata in coastal areas. Background Art

[0003] There are obvious differences between artificially transformed land and natural land. The special coastal landforms and geological and geographical environments pose many challenges to the construction of water supply and drainage pipelines. For traditional water supply and drainage pipeline construction, conventional procedures such as trench excavation, laying of cushions, pipeline laying, and trench backfilling are usually adopted, often ignoring the influence of special geological conditions in coastal areas, which lays serious quality and safety hazards for the later use and repair of pipelines. The soil layers in coastal areas are mostly coastal sedimentary silt or reclaimed soil, with characteristics of low strength, strong compressibility, high water content, and high salt content. If the pipeline foundation is not treated and the cushion is directly laid, during the later use process, due to soil quality reasons, the sand cushion is likely to be lost, resulting in the pipe bottom being voided, greatly shortening the service life of the pipeline. At the same time, improper selection of pipeline materials will also cause a series of problems. The soil in coastal areas is soft and corrosive, and higher requirements are placed on the strength and corrosion resistance of pipelines. Whether it is a pipeline with a deep buried depth of rain and sewage and high pressure, or a pressurized pipeline with a shallow buried depth of domestic and reclaimed water, damage may occur during long-term use, not only affecting the normal use of the pipeline, but also posing greater safety and quality hazards, and the maintenance is difficult and costly. In addition, if the anti-corrosion treatment of various pipe materials is not in place, in the coastal environment with high salt content and strong corrosion, it will also reduce the service life of the pipe materials and affect the normal function of the pipeline. Summary of the Invention

[0004] The present invention aims to solve the above problems, and thus provides a whole-process construction method for water supply and drainage pipelines in complex strata in coastal areas.

[0005] The technical solution adopted by the present invention to solve the above problems is as follows: A whole-process construction method for water supply and drainage pipelines in complex strata in coastal areas is carried out according to the following steps: Step 1: Conduct construction preparations, and prepare personnel, materials, and construction machinery and equipment according to construction requirements; Step 2: Measure and set out the lines. According to the requirements of the construction red line, measure and set out the boundary lines of the construction scope, and enter the next step after being verified and qualified by the supervisor; Step 3: Excavate the trench. Excavate the trench according to the measured upper excavation line, and do a good job in safety protection during the excavation process; Step 4: Select the pipe materials. Conduct a selection study on traditional plastic pipes, concrete pipes, reinforced concrete pipes, steel pipes, and cast iron pipes, and select the pipe materials suitable for the construction of coastal municipal pipelines by comprehensively considering factors such as pipe strength, weight, and anti-corrosion characteristics; Step 5: Basic treatment, the foundation along the pipeline and inspection wells is treated by replacing the original soil with mountain skin stones and graded crushed stones. Step 6: Pipeline construction. First, the pipeline is subjected to anti-corrosion treatment, including applying diluted epoxy varnish primer, two coats of epoxy anti-corrosion paint, and one coat of epoxy varnish. Then, the pipeline is laid according to the construction process. Step 7: Masonry of inspection wells. First, the cushion layer is constructed, and a high-efficiency anti-corrosion agent is incorporated into the cushion concrete. Then, the main body construction is carried out to improve the strength grade and impermeability grade of the main body concrete, and an anti-corrosion, anti-cracking and waterproof agent is incorporated. Finally, anti-corrosion construction consistent with the pipeline anti-corrosion construction process is carried out. Step 8: Construction of branch pipes. The branch pipes are wrapped with concrete, and fiberglass geogrid is laid along the entire line of the branch pipes. Step 9: Backfilling of the pipeline. Medium-coarse sand is used for backfilling the pipeline. Step 10: Pipeline test and acceptance. After the pipeline construction is completed, test detection is carried out, and acceptance is carried out after the test is completed.

[0006] Further, the thickness of the mountain skin stone replacement is 700mm, the maximum particle size of the mountain skin stone is less than 20cm, the proportion of crushed stones is higher than 85%, and the compaction settlement difference control is adopted. The average value of the elevation differences of each measuring point after rolling is less than 5mm, and the standard deviation is less than 3mm.

[0007] Further, the graded crushed stone is filled and compacted in layers, the layer thickness is less than 20cm, and the compaction degree is greater than 90%.

[0008] Further, in the pipeline anti-corrosion treatment, the painting method and thickness of each layer of anti-corrosion paint are controlled within 5μm - 8μm.

[0009] Further, the fiberglass geogrid is an alkali-free grid, the alkali metal oxide content is less than 0.8%, the mesh shape of the fiberglass geogrid is rectangular, the size is 20*20mm, the ultimate tensile strength is greater than 50kN / m, the ultimate elongation rate is less than 4%, and the breaking strength after thermal aging is greater than 90% of the original strength.

[0010] The present invention adopting the above technical solution, compared with the prior art, its prominent features are: By replacing the original soil of the pipeline foundation, the stability and bearing capacity of the pipe foundation are enhanced, effectively reducing the potential safety and quality hazards of the pipeline caused by foundation problems; reasonable selection of pipe materials comprehensively considers the special environment in coastal areas, improving the service life of the pipeline; scientific pipeline anti-corrosion technology significantly improves the anti-corrosion performance of the pipe materials, ensuring the long-term stable operation of the pipeline; in addition, this construction method also reduces the damage to the pipeline in later use, reduces the excavation of the road surface structure, shortens the construction period, and saves engineering costs. Description of the Drawings

[0011] Figure 1 This is the construction framework diagram of the embodiment of the present invention; Specific implementation manners

[0012] The present invention will be further described below in conjunction with embodiments. The purpose is only to better understand the content of the present invention. Therefore, the examples given do not limit the protection scope of the present invention.

[0013] See Figure 1 , a whole-process construction method for water supply and drainage pipelines in complex strata in coastal areas, which is carried out according to the following steps: First, prepare sufficient construction personnel, materials meeting quality standards, and mechanical equipment with good performance according to construction requirements.

[0014] Then, based on the construction red line, accurately measure and set the construction range boundary line. After being strictly verified and qualified by the supervision personnel, start the trench excavation operation, and set up perfect safety protection facilities during the excavation process to ensure the safety of construction personnel.

[0015] In the pipe material selection link, conduct a detailed selection study on various pipe materials. For steel pipes, their high strength but easy corrosion characteristics need to be considered key points; although plastic pipes are light in weight and low in transportation and installation costs, their strength is relatively low; concrete pipes and reinforced concrete pipes have their own characteristics in terms of weight and strength; comprehensively consider and select steel pipes and reinforced concrete pipes as the selected pipe materials.

[0016] During foundation treatment, the foundation along the pipeline and inspection wells is backfilled with mountain skin stones. The backfill thickness of mountain skin stones is 700mm, the maximum particle size of mountain skin stones is less than 20cm, the proportion of crushed stones is higher than 85%, and there should be no obvious cavities and pores on the top surface of the filled stones; use the compaction settlement difference for control to ensure that the average elevation difference of each measurement point after compaction is less than 5mm and the standard deviation is less than 3mm; then carry out graded crushed stone backfill, compacted in layers, the layer thickness is less than 20cm, and the compaction degree is greater than 90%.

[0017] Before pipeline construction, anti-corrosion treatment is carried out first. The inner and outer walls of the pipeline are first coated with diluted epoxy varnish as the primer, with the thickness controlled at 5μm - 8μm, then coated with two coats of epoxy anti-corrosion paint, and finally coated with one coat of epoxy varnish; after the anti-corrosion treatment is completed, the pipeline laying is carried out according to the established construction process.

[0018] During the construction of inspection wells, 3% - 5% of high-efficiency anti-corrosion agent is added to the concrete during the cushion construction; the concrete strength grade is increased from C25 to C35 and the anti-seepage grade is increased from P6 to P8 during the main body construction, and 8% - 10% of CMA anti-corrosion and anti-cracking waterproof agent is added; the anti-corrosion construction is the same as the pipeline anti-corrosion construction process.

[0019] During the construction of the branch pipe, the branch pipe is wrapped with C25 concrete and fiberglass geogrid is laid along the whole line of the branch pipe; the selected geogrid is an alkali-free grid with the alkali metal oxide content less than 0.8%. The mesh shape of the fiberglass geogrid is rectangular, with the size of 20*20mm, the ultimate tensile strength is greater than 50kN / m, the ultimate elongation rate is less than 4%, and the breaking strength after heat aging is greater than 90% of the original strength.

[0020] The pipeline backfill uses medium coarse sand and is strictly carried out in accordance with relevant specifications. After the pipeline construction is completed, comprehensive test detection is carried out, and after passing the detection, the pipeline acceptance is carried out.

[0021] Through the above construction process, the whole-process construction method of the water supply and drainage pipeline in the complex stratum of the coastal area of the present invention can effectively solve the construction problems of the water supply and drainage pipeline in the coastal area and achieve the expected technical effects.

[0022] By replacing and filling the pipeline foundation, the stability and bearing capacity of the pipe foundation are enhanced, effectively reducing the potential safety and quality hazards of the pipeline caused by foundation problems; the reasonable selection of pipe materials comprehensively considers the special environment in the coastal area and improves the service life of the pipeline; the scientific pipeline anti-corrosion technology significantly improves the anti-corrosion performance of the pipe materials and ensures the long-term stable operation of the pipeline; in addition, this construction method also reduces the damage to the pipeline in later use, reduces the excavation of the road surface structure, shortens the construction period and saves the project cost.

[0023] The above are only the preferred and feasible embodiments of the present invention, and do not limit the scope of the rights of the present invention accordingly. Any equivalent changes made by using the content of the specification and drawings of the present invention are included in the scope of the rights of the present invention.

Claims

1. A construction method for the whole process of water supply and drainage pipelines in complex strata in coastal areas, characterized in that, It is carried out according to the following steps: Step 1: Prepare for construction, and prepare personnel, materials and mechanical equipment according to the construction requirements; Step 2: Measure and set out the lines. According to the requirements of the construction red line, measure and set out the sidelines of the construction scope. After being verified and qualified by the supervisor, proceed to the next step; Step 3: Excavate the trench. Excavate the trench according to the set upper excavation line, and do a good job in safety protection during the excavation process; Step 4: Select the pipe materials. Conduct a selection study on traditional plastic pipes, concrete pipes, reinforced concrete pipes, steel pipes and cast iron pipes. Considering the factors of pipe strength, weight and anti-corrosion characteristics, select the pipe materials suitable for coastal municipal pipeline construction; Step 5: Foundation treatment. Replace the foundation along the pipeline and inspection wells with mountain skin stones and graded crushed stones; Step 6: Pipeline construction. First, carry out anti-corrosion treatment on the pipeline, including brushing diluted epoxy clear paint primer, two coats of epoxy-type anti-corrosion paint and one coat of epoxy clear paint, and then lay the pipeline according to the construction process; Step 7: Build the inspection well. First, carry out the cushion construction, add a high-efficiency anti-corrosion agent to the cushion concrete, and then carry out the main body construction, improve the strength grade and anti-seepage grade of the main body concrete, and add an anti-corrosion, anti-cracking and waterproof agent. Finally, carry out anti-corrosion construction consistent with the pipeline anti-corrosion construction process; Step 8: Branch pipe construction. Encase the branch pipe with concrete and lay fiberglass geogrid along the whole line of the branch pipe; Step 9: Backfill the pipeline. Backfill the pipeline with medium-coarse sand; Step 10: Pipeline test and acceptance. Conduct test detection after the pipeline construction is completed, and conduct acceptance after the test is completed.

2. The whole-process construction method of the water supply and drainage pipeline in the complex stratum of the coastal area according to claim 1, characterized in that: The thickness of the mountain skin stone replacement is 700mm, the maximum particle size of the mountain skin stone is less than 20cm, the proportion of gravel is higher than 85%, and the compaction settlement difference is controlled. The average elevation difference of each measuring point after rolling is less than 5mm, and the standard deviation is less than 3mm.

3. The whole-process construction method of the water supply and drainage pipeline in the complex stratum of the coastal area according to claim 2, characterized in that: The graded crushed stone is filled and compacted in layers, the layer thickness is less than 20cm, and the compaction degree is greater than 90%.

4. The whole-process construction method of water supply and drainage pipelines in complex strata in coastal areas according to claim 1, characterized in that: In the pipeline anti-corrosion treatment, the brushing method and thickness of each layer of anti-corrosion paint are controlled at 5μm - 8μm.

5. The whole-process construction method of the water supply and drainage pipeline in the complex stratum of the coastal area according to claim 1, characterized in that: The fiberglass geogrid is an alkali-free grid, the alkali metal oxide content is less than 0.8%, the mesh shape of the fiberglass geogrid is rectangular, the size is 20*20mm, the ultimate tensile strength is greater than 50kN / m, the ultimate elongation is less than 4%, and the fracture strength after thermal aging is greater than 90% of the original strength.

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