Multi-row GRP pipeline backfilling method and pipeline system

Abstract

The invention relates to the technical field of GRP pipeline backfilling, in particular to a multi-row GRP pipeline backfilling method and a pipeline system. The backfilling method for the multiple rows of GRP pipelines comprises the following steps that S1, local backfilling is conducted, wherein S11, triangular areas of the GRP pipelines are backfilled; s12, local backfilling is conducted on the periphery of the GRP pipeline; s13, tamping operation is conducted after each layer is backfilled in a layered mode; s14, the step S12 and the step S13 are repeated till the pipe top of the GRP pipeline is completely covered with the backfill material; s2, full backfilling is conducted, wherein the step S2 comprises the following steps that S21, the backfilling area is backfilled with undisturbed soil; s22, the backfill area is tamped; and S23, the backfill area is compacted. According to the backfilling method, by optimizing the backfilling sequence and method, an effective solution is provided for insufficient supporting performance, pipeline deviation and damage risks of the multiple rows of large-diameter GRP pipelines in the backfilling process, the construction safety and the long-term stability of the pipelines are remarkably improved, meanwhile, the construction efficiency is improved, and the construction cost is reduced. And the time and cost loss caused by reworking is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of GRP pipeline backfilling, and in particular to a multi-row GRP pipeline backfilling method and a pipeline system. Background Art

[0002] GRP pipes (GRP pipes, also known as polyester FRP pipes) have the advantages of excellent corrosion resistance, light weight, high strength, and long service life. They are widely used in petroleum, chemical, water treatment and other fields.

[0003] At present, the conventional method of pipeline backfilling is to use backfill materials to backfill the grooves at the bottom, sides and top of the pipeline after the pipeline is installed, and then perform manual or mechanical compaction after backfilling.

[0004] However, large-diameter GRP pipes have the characteristics of large diameter (diameter ≥ 3000mm), large weight (weight ≥ 20 tons) and certain brittleness. When backfilling with multiple rows of GRP pipes, they occupy a large area. When multiple rows of GRP pipes are set in the same trench, the conventional pipe backfilling method has poor support for large-diameter GRP pipes. Uneven settlement is more likely to occur after backfilling. In addition, due to the large pipe diameter, the GRP pipe is more likely to shift. The compaction process is easy to damage the GRP pipe, resulting in the need for rework and affecting the construction period. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of conventional pipeline backfilling methods, such as poor support for multiple rows of large-diameter GRP pipelines, easy displacement of GRP pipelines, and damage to GRP pipelines, and to provide a multiple-row GRP pipeline backfilling method and pipeline system.

[0006] In a first aspect, the present invention provides a method for backfilling a multi-row GRP pipe, comprising the following steps:

[0007] S1. Perform local backfilling, including the following steps:

[0008] S11. Backfill the triangular area of ​​the GRP pipe: Use the manual compaction method to push the backfill material symmetrically into the triangular area on both sides of the GRP pipe;

[0009] S12. Partially backfill the periphery of the GRP pipe: the gap between the GRP pipe and the wall of the base trench is the first gap, the gap between two adjacent GRP pipes is the second gap, and the partial backfilling is performed in layers in the longitudinal direction, and the backfilling of the first gap and the backfilling of the second gap in the transverse direction are performed synchronously and symmetrically;

[0010] S13. After backfilling each layer, compaction is performed;

[0011] S14. Repeat S12 and S13 until the backfill material completely covers the top of the GRP pipe;

[0012] S2. Perform full backfilling, including the following steps:

[0013] S21. Backfill the backfill area with original soil;

[0014] S22. Compact the backfill area;

[0015] S23. Compact the backfill area.

[0016] The multi-row GRP pipe backfilling method provided by the present invention divides the entire backfilling process into local backfilling and overall backfilling;

[0017] When backfilling locally, first backfill the triangular area of ​​the GRP pipe symmetrically to enhance the support on both sides of the bottom of the pipe. Since the GRP pipe has a large diameter and heavy deadweight, the bottom support is crucial to the overall stability of the pipe. By symmetrically backfilling the triangular area, the stress at the bottom of the pipe can be evenly distributed, reducing the structural damage caused by uneven settlement, and effectively improving the long-term stability of the pipe; when backfilling locally around the pipe, the method of longitudinal layered backfilling and transverse synchronous symmetrical backfilling is adopted. The longitudinal layered backfilling can ensure that each layer of backfill material is evenly distributed around the pipe, avoiding the problem of uneven distribution of fillers caused by traditional one-time large-area backfilling; in addition, the layered backfilling can make the GRP pipe evenly stressed, avoiding the problem of sudden increase in pipe pressure and damage to the GRP pipe due to one-time backfilling; the transverse synchronous symmetrical backfilling can ensure the lateral stability of the GRP pipe during each layer of backfilling, avoiding the problem of pipe deviation due to uneven force; compaction is carried out after each layer of backfilling, so that the position of the GRP pipe remains stable throughout the backfilling process, ensuring the quality of backfilling and significantly reducing the common problem of pipe deviation in multi-row pipe laying;

[0018] After the partial backfill is completed, the overall backfill stage begins. The top of the pipeline is backfilled with undisturbed soil to further ensure the integrity and stability of the soil around the pipeline. After the overall backfill, tamping and compaction are continued to ensure the density of the entire trench backfill, avoiding the risk of pipeline damage due to uneven settlement in the later stage.

[0019] The multi-row GRP pipe backfilling method provided by the present invention proposes an effective solution to the insufficient support, pipe deviation and damage risks of multiple rows of large-diameter GRP pipes during the backfilling process by optimizing the backfilling sequence and method, which significantly improves the construction safety and the long-term stability of the pipes, while improving the construction efficiency and reducing the time and cost losses caused by rework.

[0020] Preferably, the manual compaction method in S11 includes: preliminarily leveling the backfill material in the triangular area before manual compaction, and the construction personnel use a tool with a pointed wedge end to push the backfill material symmetrically into the triangular area on both sides of the GRP pipe, and compact in a fixed direction during manual compaction.

[0021] With this treatment method, before manual tamping, the backfill in the triangular area is preliminarily leveled to ensure that the backfill is evenly distributed before entering the tamping stage, avoiding local voids and stress concentration caused by uneven distribution of the backfill; using a tool with a pointed wedge end to push the backfill symmetrically into the triangular area on both sides of the pipe, the backfill can be sent to every corner of the triangular area more accurately, ensuring that the backfill can tightly fill the space between the pipe and the groove wall, avoiding voids or incomplete filling; using a fixed direction tamping method to ensure that each position can obtain a uniform compaction effect during tamping. This not only makes the density of the backfill more uniform, but also reduces the problem of uneven stress caused by inconsistent directions during the tamping process.

[0022] Preferably, the backfill material in S14 completely covers the top of the GRP pipe and is backfilled to 300±50 mm above the top of the GRP pipe.

[0023] The backfill layer that completely covers the top of the pipe and extends to 300±50mm above the top of the pipe can form a thick protective layer on the top of the pipe. This layer of backfill can not only protect the pipe from direct pressure from external loads (such as construction equipment, vehicle passing, etc.), but also reduce the impact of external environmental changes (such as temperature, humidity, etc.) on the pipe, and prevent the material performance of the GRP pipe from degrading due to environmental fluctuations; at the same time, by increasing the thickness of the backfill, the gap around the pipe can be effectively reduced, slowing down and homogenizing the soil settlement.

[0024] Preferably, when backfilling in layers in S12, the thickness of each backfill layer is 300±50 mm.

[0025] With this setting, when backfilling in layers, each layer is controlled within the thickness range of 300±50mm, which can ensure that each layer of backfill can be fully compacted. A thicker backfill layer is difficult to achieve uniform compaction, while a too thin backfill layer increases construction time and cost. By controlling the thickness within a reasonable range of 300±50mm, each layer of backfill can evenly distribute the compaction force during the compaction process, ensuring that the density meets the design requirements, thereby improving the support stability of the pipeline and reducing the risk of settlement.

[0026] Preferably, the backfilling of the first gap and the backfilling of the second gap in S12 are performed synchronously and symmetrically, and include the following steps:

[0027] The second gap is backfilled at the same time as the first gap is backfilled. When the second gap is backfilled, the second gap is backfilled from the second gaps on both sides of the foundation trench to the second gap in the middle of the foundation trench.

[0028] With this setting, when backfilling the first gap and the second gap simultaneously, the left-right symmetric operation can ensure that each GRP pipe is subjected to uniform lateral support force, preventing the pipe from tilting or deflecting due to faster or uneven backfilling on one side, and preventing the pipe from being damaged due to uneven force on both sides of the pipe. Especially for large-diameter pipes, uneven lateral force is more likely to cause deflection or instability. Synchronous symmetric backfilling can effectively improve the lateral stability of the pipe.

[0029] When backfilling the second gap, the method of gradually backfilling from both sides of the foundation trench to the middle can avoid premature accumulation of filler in the middle area and keep the entire backfilling process stable. This can ensure that the filler between adjacent pipes is gradually advanced, reducing local settlement or uneven compaction caused by premature accumulation of backfill in the middle. This backfilling method can gradually increase the support force of the filler and make the support between adjacent pipes more uniform, avoiding unbalanced force on the pipes.

[0030] Preferably, the backfilling of the first gap and the backfilling of the second gap in S12 are performed synchronously and symmetrically, and include the following steps:

[0031] The second gap is backfilled at the same time as the first gap is backfilled. The second gap is backfilled from one side of the foundation trench to the other side of the foundation trench.

[0032] With this setting, backfilling from one side of the foundation trench to the other side can effectively build a support structure step by step in each layer. With backfilling, the backfill material will not be piled up on one side at once, avoiding excessive unilateral pressure on the pipe or foundation trench. Backfilling can maintain uniform force distribution throughout the backfilling process. Compared with filling the entire backfill area at once, backfilling can avoid the problem of excessive filling or compaction in local areas, thereby effectively reducing the risk of pipe deformation or settlement caused by uneven local compaction. Backfilling can disperse the weight of the backfill material, so that the backfilling on each side can be carried out gradually, avoiding the problem of local settlement caused by a large amount of backfill material piled up at one time. Backfilling can make the construction process more flexible, and construction personnel can adjust the backfilling order according to the specific conditions of the foundation trench. By backfilling layer by layer, the complex mechanical conditions in the backfilling process can be effectively avoided, making the backfilling pressure and support more uniform at each step, reducing the risk of uneven distribution of backfill material or squeezing of pipes during construction.

[0033] Preferably, the compaction operation direction in S13 is from both sides of the foundation trench to the middle of the foundation trench.

[0034] Tamping from both sides of the foundation trench to the middle can ensure that the pressure of the tamping operation is gradually transferred to the middle and evenly distributed in the entire foundation trench area. If you tamp directly from one side to the other, the filler on one side may be compacted first, while the other side is not yet stable, resulting in uneven lateral force on the pipeline. When tamping gradually from both sides to the middle, the tamping force is symmetrically concentrated in the middle, so that all areas where the backfill material contacts the pipeline can be evenly compacted, ensuring that the filler support around the pipeline is more uniform, thereby reducing deformation or damage to the pipeline surface caused by uneven force; at the same time, while gradually tamping the backfill material, it can better disperse the pressure of the underlying soil layer, avoid excessive compression of the filler in a local area due to unilateral tamping, and help reduce the settlement of the foundation trench or pipeline caused by uneven tamping after backfilling.

[0035] Preferably, the compaction operation in S13 is performed using wet sand.

[0036] Wet sand is easier to compact and can better fill the gaps in the backfill area during the compaction process, forming a tight structure and improving the overall density, thereby effectively supporting large-diameter GRP pipes and reducing the risk of uneven stress.

[0037] Preferably, in S23, when the top of the GRP pipe in the backfill area has a soil cover of more than 300-500 mm, a roller is used to compact the backfill area.

[0038] Sufficient cover soil thickness can provide good protection for the GRP pipes, prevent the GRP pipes from being damaged during operation of the roller, and reduce the risk of pipe damage.

[0039] In a second aspect, the present invention provides a pipeline system, which is backfilled using the above-mentioned multi-row GRP pipe backfilling method, including a foundation trench, a cushion layer is laid at the bottom of the foundation trench, the cushion layer is made of SC1 material or 3 / 4 crushed stone, and the compaction degree of the cushion layer is more than 90%; five GRP pipes are laid side by side on the cushion layer, the pipe circumference of the GRP pipe is wrapped by backfill material, the backfill material covers 300±50mm above the top of the GRP pipe, the backfill material is SC2 material, and the compaction degree of the backfill material is more than 90%; above the backfill material is original soil, the thickness of the original soil is 300-500mm, and the compaction degree of the original soil is more than 90%.

[0040] The bottom of the pipeline system provided by the present invention is laid with a cushion layer, which can effectively enhance the support of the pipeline and ensure long-term settlement control; the backfill material is wrapped around the pipeline and covers the top of the pipe by 300±50mm to form a good protective layer to resist external pressure and evenly distribute the pressure on the pipeline, reducing the risk of local overload; the upper layer of original soil is backfilled with a thickness of 300-500mm to provide additional stability, thereby reducing the risk of pipeline settlement and displacement. The pipeline system has a stable structure and ensures the service life of the GRP pipeline.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] 1. The multi-row GRP pipe backfilling method provided by the present invention divides the entire backfilling process into local backfilling and overall backfilling. During local backfilling, the triangular area of ​​the GRP pipe is first symmetrically backfilled to enhance the support of both sides of the bottom of the pipe. Since the GRP pipe has a large diameter and heavy deadweight, the bottom support is crucial to the overall stability of the pipe. By symmetrically backfilling the triangular area, the stress at the bottom of the pipeline can be evenly distributed, reducing the structural damage caused by uneven settlement and effectively improving the long-term stability of the pipeline. When performing local backfilling around the pipe, the method of longitudinal layered backfilling and transverse synchronous symmetrical backfilling is adopted. The longitudinal layered backfilling can ensure that each layer of backfill material is evenly distributed around the pipeline, avoiding the problem of uneven distribution of backfill material caused by traditional one-time large-area backfilling. In addition, the layered backfilling can make the GRP pipe evenly stressed, avoiding the problem of sudden increase in pipe pressure and damage to the GRP pipe due to one-time backfilling. The transverse synchronous symmetrical backfilling can ensure the lateral stability of the GRP pipe during each layer of backfilling, avoiding the problem of pipe displacement due to uneven stress. After each layer of backfilling, compaction is carried out to ensure that the position of the GRP pipe remains stable throughout the backfilling process, ensuring the backfilling quality and significantly reducing the common pipe displacement problem in the laying of multiple rows of pipes. After the local backfilling is completed, the overall backfilling stage is entered, and the top of the pipe is backfilled with original soil to further ensure the integrity and stability of the soil around the pipe. After the overall backfill, tamping and compaction are continued to ensure the density of the entire trench backfill and avoid the risk of pipeline damage caused by uneven settlement in the later stage;

[0043] 2. The multi-row GRP pipe backfilling method provided by the present invention provides an effective solution to the insufficient support, pipe deviation and damage risks of multi-row large-diameter GRP pipes during the backfilling process by optimizing the backfilling sequence and method, which significantly improves the construction safety and long-term stability of the pipes, while improving the construction efficiency and reducing the time and cost losses caused by rework;

[0044] 3. The bottom of the pipeline system provided by the present invention is laid with a cushion layer, which can effectively enhance the support of the pipeline and ensure long-term settlement control; the backfill material is wrapped around the pipeline and covers the top of the pipe by 300±50mm to form a good protective layer to resist external pressure and evenly distribute the pressure on the pipeline, reducing the risk of local overload; the original soil on the upper layer is backfilled with a thickness of 300-500mm to provide additional stability, thereby reducing the risk of pipeline settlement and displacement. The pipeline system has a stable structure and ensures the service life of the GRP pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 A flow chart of the multi-row GRP pipe backfilling method provided by the present invention;

[0046] Figure 2 This is a schematic diagram of the backfill of the triangular area of ​​the GRP pipe;

[0047] Figure 3 This is a schematic diagram of five GRP pipes installed in the foundation trench;

[0048] Figure 4 A cross-sectional view of the piping system provided for Example 3.

[0049] Markings in the figure:

[0050] 1-GRP pipe, 2-foundation trench, 3-wooden sticks, 100-first gap, 200-second gap, 300-backfill, 400-original soil, 500-cushion. DETAILED DESCRIPTION

[0051] The present invention is further described in detail below in conjunction with specific embodiments. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0052] Unless otherwise specified, in the description of the specific embodiments of the present invention, the terms indicating the orientation or position relationship such as "up", "down", "left", "right", "center", "inside", "outside", etc. are all based on the expression of the orientation or position relationship shown in the drawings, or are the orientation or position relationship when the invented product / equipment / device is usually used. These terms of orientation or position relationship are only for the convenience of describing the scheme of the present invention or simplifying the description in the specific embodiments, so as to facilitate the technicians to quickly understand the scheme, and do not indicate or imply that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific position relationship, and therefore cannot be understood as a limitation on the present invention.

[0053] In addition, if the terms "horizontal", "vertical", "overhanging", "parallel" and the like appear, it does not mean that the corresponding devices / components / elements are required to be absolutely horizontal or vertical or overhanging or parallel, but may be slightly tilted or have deviations. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but may be slightly tilted. Alternatively, it can be simplified to mean that the corresponding devices / components / elements are set in directions such as "horizontal", "vertical", "overhanging", "parallel", etc., and can have an error / deviation of ±10% relative to the corresponding direction setting, more preferably an error / deviation within ±8%, more preferably an error / deviation within ±6%, more preferably an error / deviation within ±5%, and more preferably an error / deviation within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its role in the scheme of the present invention.

[0054] In addition, the expressions “first”, “second”, “third”, etc., which appear in the terms, are merely used to distinguish the description of the same or similar components and should not be understood as emphasizing or implying the relative importance of specific components.

[0055] In addition, in the description of the embodiments of the present invention, "several", "plurality" and "a number" represent at least 2. It can be any number such as 2, 3, 4, 5, 6, 7, 8, 9, and even more than 9.

[0056] In addition, in the description of the technical solution of the present invention, unless otherwise clearly specified / defined / restricted, the terms "set", "install", "connect", "connected", "provided with", "laid", and "arranged" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, and can be welding, riveting, bolting, threading, and other commonly used connection means in the field. This connection can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the internal connection of two elements.

[0057] Example 1

[0058] like Figure 1 As shown, this embodiment provides a multi-row GRP pipe backfilling method, which is suitable for multi-row settings (e.g. Figure 2 The five GRP pipes 1) arranged side by side are backfilled with large diameter GRP pipes (diameter ≥ 3000 mm, dead weight ≥ 20 tons).

[0059] The multi-row GRP pipe backfilling method provided in this embodiment comprises the following steps:

[0060] S1. Perform local backfilling, including the following steps:

[0061] S11. Backfill the triangle area of ​​GRP pipe 1:

[0062] Specific, for example Figure 2 A schematic diagram of backfilling the triangular area is shown. The backfill material 300 can be pushed symmetrically into the triangular areas on both sides of the GRP pipe 1 by manual compaction method.

[0063] The specific method of manual compaction in this embodiment may include: firstly leveling the backfill material 300 in the triangular area before manual compaction. Then the construction personnel use a tool with a sharp wedge-shaped end to push the backfill material 300 symmetrically into the triangular areas on both sides of the GRP pipe 1. The tool with a sharp wedge-shaped end may be as follows: Figure 2 The end of the stick 3 shown is cut into a sharp wedge shape (for example, the end of the tool is like a wedge shape, presenting a gradually pointed and flat shape). It can be understood that the tool with a sharp wedge end can also be a shovel-like tool with a sharp wedge end. When tamping manually, tamping is performed in a fixed direction, for example, along the extension direction of the GRP pipe 1. When tamping manually, one tamping and half tamping can be adopted, tamping is connected, rows are connected, tamping is performed twice, and tamping is performed in layers.

[0064] The backfilling and compaction of the triangular area of ​​the GRP pipe 1 is very important and plays a key role in preventing the pipe from bending and deforming. With the above treatment method, before manual tamping, the backfill material 300 in the triangular area is preliminarily leveled to ensure that the filler is evenly distributed before entering the tamping stage, avoiding local gaps and stress concentration caused by uneven distribution of the backfill material 300; using a tool with a pointed wedge-shaped end to push the backfill material 300 symmetrically into the triangular area on both sides of the pipe, the backfill material 300 can be more accurately sent to every corner of the triangular area, ensuring that the backfill material 300 can tightly fill the space between the pipe and the groove wall, avoiding gaps or incomplete filling. If the backfilling is asymmetrical, it will easily cause the pipe to deviate; the fixed direction tamping method is used to ensure that each position can obtain a uniform compaction effect during tamping. This not only makes the density of the backfill material 300 more uniform, but also reduces the problem of uneven stress caused by inconsistent directions during the tamping process.

[0065] S12. Partially backfill the area around the GRP pipe 1:

[0066] Specifically, Figure 3 As shown, the gap between the GRP pipe 1 and the groove wall of the base groove 2 can be defined as a first gap 100 , and the gap between two adjacent GRP pipes 1 can be defined as a second gap 200 .

[0067] When backfilling locally, backfilling is carried out in layers vertically. The thickness of each layer of backfilling is 300±50mm, and the best thickness is 300mm. Controlling the thickness of each layer within the range of 300±50mm can ensure that each layer of backfill material 300 can be fully compacted. It is difficult to achieve uniform compaction effect with thicker backfill layers, while too thin backfill layers increase construction time and cost. By controlling the thickness within the reasonable range of 300±50mm, each layer of backfill material 300 can evenly distribute the compaction force during the compaction process, ensuring that the density meets the design requirements, thereby improving the support stability of the pipeline and reducing the risk of settlement.

[0068] When partially backfilling, the backfilling of the first horizontal gap 100 and the backfilling of the second gap 200 are performed synchronously and symmetrically. In this embodiment, the backfilling of the first gap 100 and the backfilling of the second gap 200 can be performed simultaneously, and the backfilling of the second gap 200 is performed from the second gaps 200 on both sides of the foundation trench 2 to the second gap 200 in the middle of the foundation trench 2. Figure 3 For example, it can be Figure 3 The number is The first gap 100 is numbered The second gap 200 is backfilled at the same time, where the number is When the second gap 200 of the base trench 2 is backfilled, the second gap 200 on both sides of the base trench 2 is backfilled toward the second gap 200 in the middle of the base trench 2, that is, The second gap 200 is symmetrically backfilled and numbered as The second gap 200 is symmetrically backfilled.

[0069] By adopting this backfilling method, when backfilling the first gap and the second gap simultaneously, the left and right symmetrical operations can ensure that each GRP pipe 1 is subjected to uniform lateral support force, and prevent the pipe from tilting or deflecting due to faster backfilling or uneven backfilling on one side, and the pipe from being damaged due to uneven force on both sides of the pipe. Especially for large-diameter pipes, uneven lateral force is more likely to cause deflection or instability. By synchronous and symmetrical backfilling, the lateral stability of the pipe can be effectively improved.

[0070] When backfilling the second gap 200, the method of gradually backfilling from both sides of the base trench 2 to the middle can avoid premature accumulation of filler in the middle area, so that the entire backfilling process remains stable. This can ensure that the filler between adjacent pipes is gradually advanced, reducing the local settlement or uneven compaction caused by premature accumulation of backfill 300 in the middle. This backfilling method can gradually increase the support force of the filler and make the support between adjacent pipes more uniform, avoiding unbalanced force on the pipes.

[0071] S13. After backfilling each layer, compaction is performed;

[0072] For example, after the first layer of backfill material (thickness of 300±50mm) is backfilled, tamping is performed. In this embodiment, the tamping direction can be from both sides of the foundation trench 2 to the middle of the foundation trench 2. This tamping method can ensure that the pressure of the tamping operation is gradually transferred to the middle and evenly distributed in the entire foundation trench 2 area. If tamping is performed directly from one side to the other side, the filler on one side may be compacted first, while the other side is not yet stable, resulting in uneven lateral force on the pipeline.

[0073] When tamping is performed gradually from both sides to the middle, the tamping force is symmetrically concentrated in the middle, so that each area where the backfill material 300 contacts the pipeline can be evenly compacted, ensuring that the filler support around the pipeline is more uniform, thereby reducing deformation or damage to the pipeline surface caused by uneven force; at the same time, while gradually compacting the backfill material 300, the pressure of the underlying soil layer can be better dispersed, avoiding excessive compression of the filler in a local area due to unilateral over-rapid compaction, which helps to reduce the settlement of the foundation trench 2 or the pipeline caused by uneven compaction after backfilling.

[0074] Furthermore, in this embodiment, the compaction operation can be performed using wet sand, which is easier to compact and can better fill the gaps in the backfill area during the compaction process, forming a compact structure and improving the overall density, thereby effectively supporting the large-diameter GRP pipe 1 and reducing the risk of uneven force.

[0075] S14. Repeat S12 and S13 until the backfill material 300 completely covers the top of the GRP pipe 1.

[0076] Furthermore, S14 is to repeat S12 and S13 until the backfill material 300 completely covers the top of the GRP pipe 1 and is backfilled to 300±50mm above the top of the GRP pipe 1. This backfilling method can form a thick protective layer on the top of the pipe. This layer of backfill material 300 can not only protect the pipe from direct pressure from external loads (such as construction equipment, vehicle passing, etc.), but also reduce the impact of external environmental changes (such as temperature, humidity, etc.) on the pipe, and prevent the material performance of the GRP pipe 1 from being degraded due to environmental fluctuations; at the same time, by increasing the thickness of the backfill material 300, the gap around the pipe can be effectively reduced, slowing down and homogenizing the soil settlement.

[0077] S2. Perform full backfilling, including the following steps:

[0078] S21. Backfill the backfill area with the original soil 400;

[0079] S22. Compact the backfill area;

[0080] S23. Compact the backfill area. In this embodiment, when the top of the GRP pipe 1 in the backfill area has a soil cover of more than 300-500 mm, a roller can be used to compact the backfill area. Sufficient thickness of the soil cover can provide good protection for the GRP pipe 1, prevent the GRP pipe 1 from being damaged during operation by the roller, and reduce the risk of pipe damage.

[0081] The multi-row GRP pipe backfilling method provided in this embodiment divides the entire backfilling process into local backfilling and overall backfilling;

[0082] When partially backfilling, first symmetrically backfill the triangular area of ​​GRP pipe 1 to enhance the support on both sides of the bottom of the pipe. Since GRP pipe 1 has a large diameter and heavy deadweight, the support at the bottom is crucial to the overall stability of the pipe. By symmetrically backfilling the triangular area, the stress at the bottom of the pipe can be evenly distributed, reducing structural damage caused by uneven settlement, and effectively improving the long-term stability of the pipe.

[0083] When performing local backfilling around the pipe, the method of longitudinal layered backfilling and transverse synchronous symmetrical backfilling is adopted. The longitudinal layered backfilling can ensure that the backfill material 300 of each layer is evenly distributed around the pipe, avoiding the problem of uneven distribution of backfill material caused by traditional one-time large-area backfilling; in addition, the layered backfilling can make the GRP pipe 1 evenly stressed, avoiding the problem of sudden increase in pipe pressure and damage to the GRP pipe 1 due to one-time backfilling.

[0084] Laterally synchronous and symmetrical backfilling can ensure the lateral stability of the GRP pipe 1 during each layer of backfilling, and avoid the problem of pipe deviation due to uneven force. After each layer of backfilling, compaction work is carried out to ensure that the position of the GRP pipe 1 remains stable during the entire backfilling process, ensuring the backfilling quality and significantly reducing the common pipe deviation problem in the laying of multiple rows of pipes.

[0085] After the partial backfill is completed, the overall backfill stage begins. The top of the pipeline is backfilled with 400 original soil to further ensure the integrity and stability of the soil around the pipeline. After the overall backfill, tamping and compaction are continued to ensure the density of the entire trench backfill and avoid the risk of pipeline damage caused by uneven settlement in the later stage.

[0086] In summary, the multi-row GRP pipe backfilling method provided in this embodiment, by optimizing the backfilling sequence and method, proposes an effective solution to the insufficient support, pipe deviation and damage risks of multiple rows of large-diameter GRP pipes during the backfilling process, significantly improves the construction safety and the long-term stability of the pipe, while improving the construction efficiency and reducing the time and cost losses caused by rework.

[0087] Example 2

[0088] Different from the first embodiment, in the present embodiment S12, the backfilling of the first gap 100 and the backfilling of the second gap 200 are performed synchronously and symmetrically, and include the following steps:

[0089] The second gap 200 is backfilled while the first gap 100 is backfilled. The second gap 200 is backfilled from one side of the foundation trench 2 to the other side of the foundation trench 2 .

[0090] by Figure 3 For example, it can be Figure 3 The number is The first gap 100 is numbered The second gap 200 is backfilled at the same time, where the number is The second gap 200 may be numbered when backfilled. The second gap 200 is symmetrically backfilled and numbered as The second gap 200 of can also be numbered The second gap 200 is symmetrically backfilled and numbered as The second gap 200 is symmetrically backfilled. After the backfilling of the same layer in the longitudinal direction is completed, the next step is carried out.

[0091] By adopting this backfilling method, the support structure can be effectively established step by step in each layer by backfilling from one side of the foundation trench 2 to the other side. By backfilling at intervals, the backfill material 300 will not be accumulated on one side at once, thus avoiding excessive unilateral pressure on the pipeline or the foundation trench 2.

[0092] Interval backfilling can maintain uniform force distribution throughout the backfilling process. Compared with filling the entire backfill area at one time, interval backfilling can avoid the problem of excessive filling or compaction in local areas, thereby effectively reducing the risk of pipeline deformation or settlement caused by local uneven compaction.

[0093] The interval backfilling can disperse the weight of the backfill material 300, so that the backfilling on each side can be carried out gradually, thereby avoiding the local settlement problem caused by a large amount of backfill material 300 being piled up at one time.

[0094] Interval backfilling can make the construction process more flexible, and the construction personnel can adjust the backfilling order according to the specific conditions of the foundation trench 2. By backfilling layer by layer, the complex mechanical conditions in the backfilling process can be effectively avoided, making the backfilling pressure and support of each step more uniform, and reducing the risk of uneven distribution of backfill material 300 or squeezing of pipes during construction.

[0095] In this embodiment, if a pressure test is required at the joint of the GRP pipe 1, the joint of the GRP pipe 1 can be reserved during backfilling, and after the test, the backfilling is performed manually in layers, and a small roller and a small tamping machine are used to perform layered compaction.

[0096] Example 3

[0097] This embodiment provides a pipeline system, which is backfilled using the multi-row GRP pipeline backfilling method provided in Embodiment 1 or Embodiment 2.

[0098] like Figure 4 As shown, the pipeline system includes a foundation trench 2, a cushion layer 500 is laid at the bottom of the foundation trench 2, the cushion layer 500 is made of SC1 material or 3 / 4 crushed stone, and the compaction degree of the cushion layer 500 is more than 90%; five GRP pipes 1 are laid side by side on the cushion layer 500, and the pipe circumference of the GRP pipe 1 is wrapped by backfill material 300, and the backfill material 300 covers 300±50mm above the pipe top of the GRP pipe 1, the backfill material 300 is SC2 material, and the compaction degree of the backfill material 300 is more than 90%; above the backfill material 300 is the original soil 400, the thickness of the original soil 400 is 300-500mm, and the compaction degree of the original soil 400 is more than 90%.

[0099] The above-mentioned SC1 material and SC2 material are the classifications of SC1 to SC5 for several types of backfill soil in the pressure GRP pipe standard AWWA C950 (ANSI / AWWA C950-13) promulgated by the American Water Works Association.

[0100] The cushion layer 500 laid at the bottom of the pipeline system provided in this embodiment can effectively enhance the support of the pipeline and ensure long-term settlement control; the backfill material 300 is wrapped around the pipeline and covers the top of the pipe by 300±50mm to form a good protective layer to resist external pressure and evenly distribute the pressure on the pipeline, reducing the risk of local overload; the upper layer of undisturbed soil 400 is backfilled with a thickness of 300-500mm to provide additional stability, thereby reducing the risk of pipeline settlement and displacement. The pipeline system has a stable structure and ensures the service life of the GRP pipeline 1.

[0101] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for backfilling multiple rows of GRP pipes, characterized in that: The following steps are involved: S1. Perform local backfilling, including the following steps: S11. Backfilling the triangular area of ​​the GRP pipe (1): using a manual compaction method, push the backfill material (300) symmetrically into the triangular area on both sides of the GRP pipe (1); S12. Partial backfilling is performed around the GRP pipe (1): the gap between the GRP pipe (1) and the wall of the base trench (2) is a first gap (100), and the gap between two adjacent GRP pipes (1) is a second gap (200). When partially backfilling, backfilling is performed in layers in the longitudinal direction, and backfilling of the first gap (100) and the second gap (200) in the transverse direction are performed synchronously and symmetrically; S13. After backfilling each layer, compaction is performed; S14. Repeat S12 and S13 until the backfill material (300) completely covers the top of the GRP pipe (1); S2. Perform full backfilling, including the following steps: S21. Backfill the backfill area using the original soil (400); S22. Compact the backfill area; S23. Compact the backfill area.

2. A multi-row GRP pipe backfilling method according to claim 1, characterized in that: The manual compaction method in S11 includes: before manual compaction, the backfill material (300) in the triangular area is initially leveled, and the construction personnel use a tool with a pointed wedge-shaped end to push the backfill material (300) symmetrically into the triangular areas on both sides of the GRP pipe (1), and compact in a fixed direction during manual compaction.

3. A multi-row GRP pipe backfilling method according to claim 1, characterized in that: In S14, the backfill material (300) completely covers the top of the GRP pipe (1) and is backfilled to 300±50 mm above the top of the GRP pipe (1).

4. A multi-row GRP pipe backfilling method according to claim 3, characterized in that: In S12, the thickness of each layer of backfill is 300±50mm when backfilling in layers.

5. A multi-row GRP pipe backfilling method according to claim 1, characterized in that: In S12, the backfilling of the first gap (100) and the backfilling of the second gap (200) are performed synchronously and symmetrically, and include the following steps: The second gap (200) is backfilled while the first gap (100) is backfilled. The second gap (200) is backfilled from the second gaps (200) on both sides of the base trench (2) to the second gap (200) in the middle of the base trench (2).

6. A multi-row GRP pipe backfilling method according to claim 1, characterized in that: In S12, the backfilling of the first gap (100) and the backfilling of the second gap (200) are performed synchronously and symmetrically, and include the following steps: The second gap (200) is backfilled while the first gap (100) is backfilled. The second gap (200) is backfilled from one side of the base trench (2) to the other side of the base trench (2).

7. A method for backfilling multiple rows of GRP pipes according to claim 1, characterized in that: The compaction operation direction in S13 is from both sides of the foundation trench (2) to the middle of the foundation trench (2).

8. A method for backfilling multiple rows of GRP pipes according to claim 1, characterized in that: The compaction work in S13 uses wet sand for compaction.

9. A method for backfilling multiple rows of GRP pipes according to claim 3, characterized in that: In S23, when the top of the GRP pipe (1) in the backfill area has a soil cover of more than 300-500 mm, a roller is used to compact the backfill area.

10. A pipeline system, characterized in that: Backfilling is performed using any of the multi-row GRP pipe backfilling methods of claims 1-9, comprising a foundation trench (2), a cushion layer (500) is laid at the bottom of the foundation trench (2), the cushion layer (500) is made of SC1 material or 3 / 4 crushed stone, and the compaction degree of the cushion layer (500) is above 90%; five GRP pipes (1) are laid side by side on the cushion layer (500), the pipe circumference of the GRP pipe (1) is wrapped by backfill material (300), the backfill material (300) covers 300±50 mm above the top of the GRP pipe (1), the backfill material (300) is SC2 material, and the compaction degree of the backfill material (300) is above 90%; above the backfill material (300) is original soil (400), the thickness of the original soil (400) is 300-500 mm, and the compaction degree of the original soil (400) is above 90%.

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